# GCN_circulars

GRB_name: GRB230618A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34008
SUBJECT: GRB 230618A: Swift/UVOT Upper Limits
DATE:    23/06/18 17:05:34 GMT
FROM:    Paul Kuin at MSSL <npkuin@gmail.com>

N.P.M. Kuin (MSSL/UCL) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230618A
137 s after the BAT trigger (Page et al., GCN Circ. 33989).
No optical afterglow consistent with the XRT position (Evans GCN
Circ. 33990) is detected in the initial UVOT exposures. The source
was however detected in r and i (Strausbaugh et al, GCN Circ. 33992 and KAIT
(Zhang and Filipenko, GCN Cric. 34001) in clear (R).
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           137          287          147         >20.4
u_FC               296          546          246         >19.9
white              137         1022          295         >20.7
u                  296          546          246         >19.9
w1                5114         5178           63         >18.9
m2                4909         5108          197         >19.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.025 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB230618A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34009
SUBJECT: GRB 230618A: Enhanced Swift-XRT position
DATE:    23/06/18 21:36:36 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 3710 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 230618A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 196.60314, +3.30351 which is equivalent
to:

RA (J2000): 13h 06m 24.75s
Dec (J2000): +03d 18' 12.6"

with an uncertainty of 2.0 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB230618A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34024
SUBJECT: GRB 230618A: Osservatorio Astronomico Nastro verde upper limit
DATE:    23/06/19 20:14:40 GMT
FROM:    Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 <osservatorionastroverde@gmail.com>

Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report: 

We image the field of GRB 230618A detected by SWIFT (Page et al., GCN 33989)
with telescope of Nastro Verde Observatory - Sorrento (Naples), Italy. Member of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
AstroCampania Associazione

Observations began at 21:02 UT on 2023/06/18, 19 hours after GRB's detection, 
with principal telescope  SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME
I took 24 image of 60 sec each. All images are unfiltered, calibrated with masterdark and masterflat,stacked with Tycho Tracker software
We have not detected any clearly visible sources, up to 20.3th magnitude with clear sky at 
RA(J2000)  = 13h 06m 24.75s
Dec(J2000) = +03d 18' 09.3"
on a field of view 23.3 x 15.7 arcmin
   Start                   End          Rlim
21:02:25 UT            21:29:28 UT      20.3





Magnitudes were estimated with the Gaia DR2 cat. and 
are not corrected for galactic dust extinction.



The message may be cited.


GRB_name: GRB230616A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34046
SUBJECT: IPN triangulation of GRB 230616A (short)
DATE:    23/06/21 09:19:52 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the MGNS/BepiColombo and HEND/Mars Odyssey teams,

J. Benkhoff on behalf of the BepiColombo team,

D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

E. Burns on behalf of the IPN,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team,

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:

The bright, short-duration GRB 230616A
(Swift-BAT/GUANO detection: Tohuvavohu et al., GCN Circ. 33982;
AstroSat-CZTI detection: Waratkar et al., GCN Circ. 33983)
was detected by Swift (BAT), Konus-Wind, INTEGRAL (SPI-ACS),
AstroSat (CZTI), Mars-Odyssey (HEND), and BepiColombo (MGNS)
at about 74278 s UT (20:37:58).
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
  192.035 (12h 48m 08s)  +5.683 ( +5d 40' 57")
 Corners:
  192.022 (12h 48m 05s)  +5.663 ( +5d 39' 46")
  192.049 (12h 48m 12s)  +5.714 ( +5d 42' 49")
  192.048 (12h 48m 12s)  +5.702 ( +5d 42' 08")
  192.022 (12h 48m 05s)  +5.652 ( +5d 39' 06")
 ---------------------------------------------
The error box area is 0.9 sq. arcmin, and its maximum
dimension is 4 arcmin (the minimum one is 0.3 arcmin).
The Sun distance was 103 deg.

This box may be improved.

The Swift-XRT sources (D'Avanzo et al., GCN Circ. 34006)
are outside the IPN box.
There are no obvious catalogued host galaxies
(from GLADE+ catalog; Dalya et al., MNRAS 514, 1, 1403, 2022)
inside the box.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB230616_T74278/IPN

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.


GRB_name: GRB230621A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34056
SUBJECT: GRB 230621A: Fermi GBM Final Localization Correction
DATE:    23/06/22 02:13:52 GMT
FROM:    Joshua Wood at NASA/MSFC <joshua.r.wood@nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

"At 23:45:24.83 UT on 21 June 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230621A (trigger 709083929/230621990).
This trigger was initially classified as Distant Particles by the flight software,
but is in fact a GRB.

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 337.40, Dec = 41.22 (J2000 degrees, equivalent to J2000 22h 29m, +41d 13'),
with a statistical uncertainty of 4.54 degrees.

The angle from the Fermi LAT boresight is 70 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230621990/quicklook/glg_skymap_all_bn230621990.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230621990/quicklook/glg_healpix_all_bn230621990.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230621990/quicklook/glg_lc_medres34_bn230621990.gif"


GRB_name: GRB230622A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34058
SUBJECT: GRB 230622A: Swift detection of a burst
DATE:    23/06/22 10:25:32 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>


A. Melandri (INAF-OAR), A. D'Ai (INAF-IASFPA), J. A. Kennea (PSU),
K. L. Page (U Leicester) and M. H. Siegel (PSU) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 10:04:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 230622A (trigger=1176135).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 292.532, -32.922 which is 
   RA(J2000) = 19h 30m 08s
   Dec(J2000) = -32d 55' 16"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 5 sec.  The peak count rate
was ~2020 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 10:10:36.3 UT, 375.1 seconds after
the BAT trigger. No source was detected in the 2.5-s promptly available
image. We are waiting for the full dataset to detect and localise the
XRT counterpart. 

UVOT took a finding chart exposure of 114 seconds with the White filter
starting 378 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 25% of
the BAT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
BAT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.101. 

Burst Advocate for this burst is A. Melandri (andrea.melandri AT inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB230622A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34067
SUBJECT: Swift GRB 230622A: Global MASTER-Net observations report
DATE:    23/06/22 19:12:52 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 230622A ( A. Melandri et al., GCN 34058) errorbox  24809 sec after notice time and 25243 sec after trigger time at 2023-06-22 17:05:04 UT, with upper limit up to  17.1 mag. The observations began at zenith distance = 84 deg. The sun  altitude  is -17.1 deg. 

The galactic latitude b = -23 deg., longitude l =  6 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2226200

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

     497 |             MASTER- |   C |    90 | 16.9 |        
     617 |             MASTER- |   C |   110 | 17.2 |        
     762 |             MASTER- |   C |   140 | 17.3 |        
     937 |             MASTER- |   C |   170 | 17.2 |        
    1132 |             MASTER- |   C |   180 | 17.3 |        
    1332 |             MASTER- |   C |   180 | 17.2 |        
    1532 |             MASTER- |   C |   180 | 16.6 |        
    1732 |             MASTER- |   C |   180 | 17.3 |        
    1931 |             MASTER- |   C |   180 | 17.3 |        
    2132 |             MASTER- |   C |   180 | 17.3 |        
    2356 |             MASTER- |   C |   180 | 17.3 |        
    2556 |             MASTER- |   C |   180 | 17.3 |        
    2757 |             MASTER- |   C |   180 | 17.3 |        
    2957 |             MASTER- |   C |   180 | 17.2 |        
    3296 |             MASTER- |   C |   180 | 17.3 |        
   25333 |         MASTER-SAAO |   C |   180 | 16.9 |        
   25533 |         MASTER-SAAO |   C |   180 | 17.1 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230623A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34068
SUBJECT: GRB 230623A: MAXI/GSC detection
DATE:    23/06/23 09:39:20 GMT
FROM:    Motoko Serino at Aoyama Gakuin U. <serino@phys.aoyama.ac.jp>

Y. Hagiwara (Miyazaki U.), H. Negoro, M. Nakajima (Nihon U.), M. Serino (AGU),
K. Kobayashi, M. Tanaka, Y. Soejima, Y. Kudo (Nihon U.),
T. Mihara, T. Kawamuro, S. Yamada, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN),
T. Sakamoto, S. Sugita, H. Hiramatsu, H. Nishikawa, A. Yoshida (AGU),
Y. Tsuboi, S. Urabe, S. Nawa, N. Nemoto (Chuo U.),
M. Shidatsu (Ehime U.),
I. Takahashi, M. Niwano, S. Sato, N. Higuchi, Y. Yatsu (Tokyo Tech),
S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, T. Kurihara (JAXA),
Y. Ueda, K. Setoguchi, T. Yoshitake, Y. Nakatani (Kyoto U.),
M. Yamauchi, Y. Umeki, Y. Otsuki (Miyazaki U.),
K. Yamaoka (Nagoya U.),
Y. Kawakubo (LSU),
M. Sugizaki (NAOC),
W. Iwakiri (Chiba U.) 
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source 
at 07:23:37 UT on 23 June 2023.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (349.981 deg, -17.842 deg) = (23 19 55, -17 50 31) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.23 deg and 0.2 deg, respectively.
The roll angle of long axis from the north direction is 40.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 185 +- 29 mCrab
(4.0-10.0keV, 1 sigma error).
Without assumptions on the source constancy, we obtain a rectangular error
box for the transient source with the following corners:
(R.A., Dec) = (349.422, -18.340) deg = (23 17 41, -18 20 23) (J2000)
(R.A., Dec) = (349.773, -18.563) deg = (23 19 05, -18 33 46) (J2000)
(R.A., Dec) = (350.604, -17.375) deg = (23 22 24, -17 22 30) (J2000)
(R.A., Dec) = (350.255, -17.153) deg = (23 21 01, -17 09 10) (J2000)
There was no significant excess flux in the previous transit at 05:50 UT
and in the next transit at 08:56 UT with an upper limit of 20 mCrab for each.


GRB_name: GRB230622A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34069
SUBJECT: GRB 230622A: Swift-XRT refined Analysis
DATE:    23/06/23 13:16:44 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

A. Melandri (INAF-OAR), A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC & INAF-OAR) reports on behalf of the Swift-XRT team:

We have analysed 3.9 ks of XRT data for GRB 230622A, from 383 s to 27.0
ks after the  BAT trigger. The data are entirely in Photon Counting
(PC) mode. Using 105 s of PC mode data and 1 UVOT image, we find an
enhanced XRT position (using the XRT-UVOT alignment and matching UVOT
field sources to the USNO-B1 catalogue): RA, Dec = 292.51735, -32.97036
which is equivalent to:

RA (J2000): 19h 30m 04.16s
Dec(J2000): -32d 58' 13.3"

with an uncertainty of 5.4 arcsec (radius, 90% confidence).

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01176135.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230622A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34070
SUBJECT: GRB 230622A: ATCA rapid radio follow-up
DATE:    23/06/23 13:30:09 GMT
FROM:    Gemma Anderson at Curtin U <gemma.anderson@curtin.edu.au>

G. E. Anderson (Curtin), J. K. Leung (USyd), A. J. van der Horst (GWU), L. Rhodes (Oxford), A. Gulati (USyd), S. Chastain (UNM) on behalf of the PanRadio GRB collaboration

The Australia Telescope Compact Array (ATCA) rapidly performed radio observations of the long GRB 230622A (Melandri et al. GCN 34058) at 5.5 and 9 GHz as part of the Large ATCA â€œPanRadio GRBâ€ follow-up programme C3542 (PI. Anderson). ATCA was on target observing at 11:30 UT, just 1.5 hrs post-burst and observed for 10 hrs. Only 4 of the usual 6 antennas were available. Due to poor observing conditions, only ~6 hrs of data at each frequency were imaged. There is no radio source coincident with the enhanced XRT position (Evans et al. GCN 34069) with a 3 sigma upper limit of 54 and 48 microJy/beam at 5.5 and 9.0 GHz, respectively. Further observations are planned.

We thank the CSIRO Space and Astronomy staff for supporting these observations and maintaining the ATCA rapid-response observing mode. 

We acknowledge the Gomeroi people as the traditional owners of the Observatory site. The Australia Telescope Compact Array is part of the Australia Telescope National Facility (https://ror.org/05qajvd42) which is funded by the Australian Government for operation as a National Facility managed by CSIRO.


GRB_name: GRB230623A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34071
SUBJECT: GRB 230623A: Tiled Swift observations
DATE:    23/06/23 14:27:31 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>


P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a series of observations, tiled on the sky, of the
MAXI GRB 230623A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00113

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the MAXI event is high: any X-ray source
considered to be a probable afterglow candidate will be reported via a GCN Circular
after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230623A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34072
SUBJECT: MAXI GRB 230623A: MASTER optical observations
DATE:    23/06/23 15:35:27 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>


V.Lipunov, A.Kuznetsov, N.Tiurina, E.Gorbovskoy, P.Balanutsa, K.Zhirkov, O.Gress,  A.Chasovnikov, G.Antipov, D.Vlasenko,
V.Senik, V.Topolev, Ya.Kechin, Yu.Tselik, Siyu Wu, D.Cheryasov, V.Shumkov, T.Pogrosheva (Lomonosov Moscow State University,SAI,Physics Department),
C.Francile, F. Podesta, C.Lopez, R. Podesta (Observatorio Astronomico Felix Aguilar OAFA),
D.Buckley (SAAO),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez,J.Martinez,A.Corella,L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
N.M.Budnev, O.Ershova (ISU,API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational State University),
M.Gulyaev, E.Minkina (Lomonosov MSU)

MASTER-OAFA obotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)
pointed to MAXI/GSC GRB 230623A (Hagiwara et al. GCN 34068,
Trigger=2023-06-23 07:23:37 UT, not came in socket, Tnotice(GCN)=09:39:20)
at 2023-06-23 10:14:25UT through  clouds with  mlim=17.0 at first 6 images (sun alt.=-16 and sunrise), we don't find OT insode 0.23deg MAXI error-box by auto-detection system.

We also made the difference with old MASTER image and didn't find new optical sources, that can be connected with GRB.


GRB_name: GRB230623A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34073
SUBJECT: GRB 230623A: Tiled Swift observations
DATE:    23/06/23 15:44:41 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>


P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a series of observations, tiled on the sky, of the
MAXI GRB 230623A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00114

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the MAXI event is high: any X-ray source
considered to be a probable afterglow candidate will be reported via a GCN Circular
after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230623B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34076
SUBJECT: GRB 230623B: Swift/BAT-GUANO detection of a long burst outside the coded FOV 
DATE:    23/06/24 14:51:09 GMT
FROM:    Samuele Ronchini at PSU <sjs8171@psu.edu>

Samuele Ronchini (PSU), James DeLaunay (U Alabama), Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: 

Swift/BAT did not localize GRB 230623B onboard (T0: 2023-06-23T21:22:34.5 UTC, GECAM trig 195).

The GECAM notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. 

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), detects the burst with a sqrt(TS) of 19.53 in a 8.192 s analysis time bin. 

NITRATES results are consistent with a burst coming from outside the FOV, with DeltaLLHOut of -28.84.

See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut. 

GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. 

A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/


GRB_name: GRB230625A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34080
SUBJECT: GRB 230625A: Fermi GBM Final Real-time Localization
DATE:    23/06/25 18:34:49 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 18:24:10 UT on 25 Jun 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230625A (trigger 709410255.711038 / 230625767).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 321.2, Dec = -18.7 (J2000 degrees, equivalent to J2000 21h 24m, -18d 41'), with a statistical uncertainty of 3.5 degrees.

The angle from the Fermi LAT boresight is 69.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230625767/quicklook/glg_skymap_all_bn230625767.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230625767/quicklook/glg_healpix_all_bn230625767.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230625767/quicklook/glg_lc_medres34_bn230625767.gif


GRB_name: GRB230623A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34081
SUBJECT: GRB 230623A: Swift-XRT observations
DATE:    23/06/26 13:41:57 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

S. Dichiara (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U.
Leicester), E. Ambrosi (INAF-IASFPA) , M. Capalbi (INAF-IASFPA), M.
Perri (SSDC & INAF-OAR) and P.A. Evans (U. Leicester) reports on behalf
of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 230623A in a series of observations tiled on the sky. The
total exposure time is 1.8 ks, distributed over 7 tiles; the maximum
exposure at a single sky location was 807 s. The data were collected
between T0+19.9 ks and T0+38.0 ks, and are entirely in Photon Counting
(PC) mode. 

No X-ray sources have been detected. The 3-sigma upper limit in the
field (not including the regions where the tiles overlap) ranges from
~0.02 to ~0.23 ct s^-1, corresponding to a 0.3-10 keV observed flux of
6.1e-13 to 9.1e-12 erg cm^-2 s^-1 (assuming a typical GRB spectrum).

The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00113.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230622A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34082
SUBJECT: GRB 230622A: Swift-BAT refined analysis
DATE:    23/06/26 16:15:20 GMT
FROM:    Sibasish Laha at GSFC <sibasish.laha@nasa.gov>

D. M. Palmer (LANL), C. B. Markwardt (GSFC),
S. D. Barthelmy (GSFC), H. A. Krimm (NSF),
 S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),,
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230622A (trigger #1176135)
(Melandri, et al., GCN Circ. 34058).  The BAT ground-calculated position is
RA, Dec = 292.516, -32.972 deg which is
   RA(J2000)  =  19h 30m 03.8s
   Dec(J2000) = -32d 58' 20.6"
with an uncertainty of 2.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 30%.

The BAT  light curve shows a complex structure with a duration of ~ 20 sec.
The second soft peak at T~24 sec is probably due to calibration and/or instrument effects, and possibly not related to the GRB.
T90 (15-350 keV) is 18.37 +- 13.63 sec (estimated error including systematics).

The time-averaged spectrum from T-0.06 to T+23.88 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
2.52 +- 0.43.  The fluence in the 15-150 keV band is 4.1 +- 1.0 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+0.05 sec in the 15-150 keV band
is 2.8 +- 0.4 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1176135/BA/


GRB_name: GRB230625B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34084
SUBJECT: GRB 230625B: Swift/BAT-GUANO detection of a long burst
DATE:    23/06/26 23:54:39 GMT
FROM:    Samuele Ronchini at PSU <sjs8171@psu.edu>

Samuele Ronchini (PSU), James DeLaunay (U Alabama), Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: 

Swift/BAT did not localize GRB 230625B onboard (T0: 2023-06-25T07:28:45.61 UTC, CALET trig. 1371713313). 

The CALET notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169),  performed on the temporal window [T0-20 s, T0+20 s] , detects the burst with a sqrt(TS) of 10.93 in a 16.384 s analysis time bin, starting at T0+4.096 s.

NITRATES results, independently, are ambiguous with respect to whether this burst originates from inside or outside the BAT coded FOV, with a DeltaLLHOut of 12.81 and DeltaLLHPeak of 2.84.

See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.

GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/


GRB_name: GRB230618A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34085
SUBJECT: GRB 230618A: Swift-BAT refined analysis
DATE:    23/06/27 00:39:58 GMT
FROM:    Sibasish Laha at GSFC <sibasish.laha@nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), D. M. Palmer (LANL),
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):

Using the data set from T-275 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230618A (trigger #1175438)
(Page et al., GCN Circ. 33989).  The BAT ground-calculated position is
RA, Dec = 196.642, 3.278 deg which is
   RA(J2000)  =  13h 06m 34.1s
   Dec(J2000) = +03d 16' 39.6"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The BAT light curve showed a complex structure with a duration of about 200 sec.
T90 (15-350 keV) is 104.05 +- 22.86 sec (estimated error including systematics).

The time-averaged spectrum from T-27.78 to T+107.00 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.35 +- 0.15.  The fluence in the 15-150 keV band is 1.5 +- 0.2 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+9.04 sec in the 15-150 keV band
is 0.5 +- 0.1 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1175438/BA/


GRB_name: GRB230626A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34094
SUBJECT: GRB230626A: Fermi GBM Detection
DATE:    23/06/27 16:55:13 GMT
FROM:    sumanbala2210@gmail.com

S. Bala (USRA) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 14:30:22.25 UT on 26 June 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB230626A (trigger 709482627/230626604).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 146.38, Dec = 0.09 (J2000 degrees, equivalent to
J2000 09h 45m, +00d 05'), with a statistical uncertainty of 1.0 degrees.
(radius, 1-sigma containment, statistical only; there is additionally a
systematic error which we have characterized as a core-plus-tail model,
with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger
than 10 deg systematic error [Connaughton et al. 2015, ApJS, 216, 32]).

The angle from the Fermi LAT boresight is 49 degrees.

The GBM light curve consists of two peaks (the second peak is found
to be much brighter) with a duration (T90) of about 15 s (50-300 keV).
The time-averaged spectrum from T0-1.024 to T0+25.60 s is best fit by
a Band function with Epeak= 169 +/- 12 keV, alpha = -1.29 +/- 0.02
 and beta = -2.16 +/- 0.08.

The event fluence (10-1000 keV) in this time interval is
(2.55 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+11 s in the 10-1000 keV band is 35 +/- 0.5 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB230626A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34099
SUBJECT: GRB 230626A: GRBAlpha detection
DATE:    23/06/27 21:47:24 GMT
FROM:    Marianna DafÄÃ­kovÃ¡ at Masaryk University <500025@mail.muni.cz>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), yyT. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.

The long-duration GRB 230626A (Fermi/GBM detection: GCN 34094; GECAM-B detection: trigger no. 198; Konus/Wind detection at 2023-06-26 14:30:27.440 UT) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023; arXiv:2302.10048).

The detection was confirmed at the peak time 2023-06-26 14:30:29 UTC. The T90 duration measured by GRBAlpha is 14 s and the overall significance during T90 reaches 19 sigma.

The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB230626A_GCN.pdf

All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/ 
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume. 


GRB_name: GRB230628A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34101
SUBJECT: GRB 230628A: Fermi GBM Final Localization
DATE:    23/06/28 11:26:43 GMT
FROM:    Andreas von Kienlin at MPE <azk@mpe.mpg.de>

The Fermi GBM team reports the detection of a likely SHORT GRB

"At 05:35:36.16 UT on 28 June 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230628A (trigger 709623341/230628233).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 139.19, Dec = -11.54 (J2000 degrees, equivalent to J2000 9h 16m, -11d 32'),
with a statistical uncertainty of 16.84 degrees.

The angle from the Fermi LAT boresight is 51 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628233/quicklook/glg_skymap_all_bn230628233.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628233/quicklook/glg_healpix_all_bn230628233.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628233/quicklook/glg_lc_medres34_bn230628233.gif"


GRB_name: GRB230623B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34104
SUBJECT: GRB 230623B: CALET Gamma-Ray Burst Monitor detection
DATE:    23/06/28 16:39:07 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

S. Nakahira (JAXA), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), Y. Asaoka (ICRR),
S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 230623B (GECAM trigger 195; Swift/BAT-GUANO 
detection: Ronchini et al.,GCN Circ. 34076) triggered the CALET 
Gamma-ray Burst Monitor (CGBM) at 21:22:37.02 UTC on 23 
June 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1371590547/index.html).
The burst signal was seen by all CGBM detectors.  No real-time 
CGBM GCN notice was distributed about this trigger because
the real-time communication from the ISS was off (loss of signal).

The burst light curve shows a multi-peaked structure that starts
at T-3.2 sec, peaks at T+13.9 sec, and ends at T+20.4 sec.
The T90 and T50 durations measured by the SGM data are 21.4 +/- 1.5 sec
and 13.4 +/- 0.6 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1371590547/

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.


GRB_name: GRB230628B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34105
SUBJECT: GRB 230628B: Swift/BAT-GUANO detection of a burst outside the coded FOV
DATE:    23/06/28 16:42:07 GMT
FROM:    Jimmy DeLaunay at University of Alabama  <delauj2@gmail.com>

James DeLaunay (U Alabama), Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), Samuele Ronchini (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: 

Swift/BAT did not localize GRB 230628B onboard (T0: 2023-06-28T01:35:56.03 UTC, INTEGRAL trig 10298, Fermi trig. 709608965). 

The INTEGRAL and Fermi notices, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169),  performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 14.54 in a 16.384 s analysis time bin, starting at T0.

NITRATES results are consistent with a burst coming from outside the FOV, with DeltaLLHOut of 0.78. 

See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.

GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/


GRB_name: GRB230628C
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34106
SUBJECT: GRB 230628C: Fermi GBM Final Real-time Localization
DATE:    23/06/28 17:47:08 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 17:36:34 UT on 28 Jun 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230628C (trigger 709666599.86266 / 230628734).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 301.0, Dec = 35.6 (J2000 degrees, equivalent to J2000 20h 03m, 35d 36'), with a statistical uncertainty of 3.3 degrees.

The angle from the Fermi LAT boresight is 18.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628734/quicklook/glg_skymap_all_bn230628734.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628734/quicklook/glg_healpix_all_bn230628734.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628734/quicklook/glg_lc_medres34_bn230628734.gif


GRB_name: GRB230628D
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34108
SUBJECT: GRB 230628D: Fermi GBM Final Real-time Localization
DATE:    23/06/28 20:32:52 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 20:22:31 UT on 28 Jun 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230628D (trigger 709676556.5632 / 230628849).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 175.0, Dec = 12.3 (J2000 degrees, equivalent to J2000 11h 39m, 12d 18'), with a statistical uncertainty of 1.6 degrees.

The angle from the Fermi LAT boresight is 25.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628849/quicklook/glg_skymap_all_bn230628849.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628849/quicklook/glg_healpix_all_bn230628849.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230628849/quicklook/glg_lc_medres34_bn230628849.gif


GRB_name: GRB230628D
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34109
SUBJECT: GRB 230628D: BALROG localization (Fermi Trigger 709676556 / GRB 230628849)
DATE:    23/06/28 20:54:04 GMT
FROM:    Jochen Greiner at MPE <jcgrog@mpe.mpg.de>

T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
709676556 at 20:22:31 on 28 June 2023 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 177.0+/-1.2 deg
Decl.(2000.0) = 3.0+/-1.1 deg
We estimate an additional systematic error of 2 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB230628849/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB230628849/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB230628849/json

                        


GRB_name: GRB230628E
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34110
SUBJECT: GRB 230628E: Swift detection of a burst
DATE:    23/06/28 23:00:04 GMT
FROM:    N. Klingler at NASA-GSFC/UMBC/CRESST II <noelklingler@gmail.com>

CRESSTII), C. Salvaggio (INAF-OAB), T. Sbarrato (INAF-OAB), M. H. Siegel (PSU) and M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift Observatory Team:

At 22:26:10 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 230628E (trigger=1177054).  Swift slewed immediately to the burst.  The BAT on-board calculated location is 
RA, Dec 171.841, -11.447 which is 
   RA(J2000) = 11h 27m 22s
   Dec(J2000) = -11d 26' 47"
with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty).  The BAT light curve showed a single peaked structure with a duration of about 5 sec.  The peak count rate was ~600 counts/sec (15-350 keV), at ~0 sec after the trigger.

The XRT began observing the field at 22:29:48.3 UT, 217.7 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 171.8499, -11.4641 which is equivalent to:
   RA(J2000)  = +11h 27m 23.77s 
   Dec(J2000) = -11d 27' 50.2â€
with an uncertainty of 1.9 arcseconds (radius, 90% containment).  This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper.  No spectrum from the
promptly downlinked event data is yet available to determine the column density.

UVOT took a finding chart exposure of 150 seconds with the White filter starting 221 seconds after the BAT trigger.  No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers none of the XRT error circle. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle.  The list of sources is typically complete to about 18 mag.  No correction has been made for the expected extinction corresponding to E(B-V) of 0.040.

Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst.  In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB230628E
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34112
SUBJECT: GRB 230628E: LCOGT Optical Upper Limit
DATE:    23/06/29 00:32:59 GMT
FROM:    Robert Strausbaugh at University of Minnesota <rstrausb@umn.edu>

R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on behalf
of a larger collaboration:

We observed the GRB 230628E (Klingler et al., GCN 34110) field with the LCOGT
1-meter Sinistro instrument at the Cerro Tololo Interamerican Observatory,
Chile site, on June 28, from 23:08 to 23:40 UT (corresponding to 0.70 to
1.23 hours from the GRB trigger time) with the SDSS r and i filters.

We performed a series of 3x300s exposures in each band.  We do not detect a
source within the Swift-XRT error region (Klingler et al., GCN 34110) in
either band.

The following upper limits are calculated using the PanSTARRS catalog as
reference:

r > 19.2

i > 19.0

These magnitudes are not corrected for galactic extinction.


GRB_name: GRB230628D
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34114
SUBJECT: Fermi GRB 230628D: Global MASTER-Net observations report
DATE:    23/06/29 02:00:34 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-OAFA robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 230628D ( Fermi GBM team, GCN 34108) errorbox  15347 sec after notice time and 15383 sec after trigger time at 2023-06-29 00:38:54 UT, with upper limit up to  19.0 mag. The observations began at zenith distance = 60 deg. The sun  altitude  is -36.9 deg. 

The galactic latitude b = 68 deg., longitude l = 253 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2230025

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   15473 | 2023-06-29 00:38:54 |         MASTER-OAFA | (11h 38m 17.90s , +12d 57m 37.4s) |   C |   180 | 18.3 |        
   15653 | 2023-06-29 00:38:54 |         MASTER-OAFA | (11h 38m 17.90s , +12d 57m 37.4s) |   C |   540 | 19.0 |  Coadd 
   15685 | 2023-06-29 00:42:26 |         MASTER-OAFA | (11h 38m 23.91s , +12d 56m 35.9s) |   C |   180 | 18.2 |        
   16524 | 2023-06-29 00:56:25 |         MASTER-OAFA | (11h 38m 20.58s , +12d 55m 38.5s) |   C |   180 | 18.1 |        
   18504 | 2023-06-29 01:29:25 |         MASTER-OAFA | (11h 42m 15.16s , +13d 09m 29.7s) |   C |   180 | 17.8 |        
   18684 | 2023-06-29 01:29:25 |         MASTER-OAFA | (11h 42m 15.16s , +13d 09m 29.7s) |   C |   540 | 18.5 |  Coadd 
   18716 | 2023-06-29 01:32:57 |         MASTER-OAFA | (11h 42m 15.00s , +13d 08m 03.9s) |   C |   180 | 17.8 |        
   18927 | 2023-06-29 01:36:28 |         MASTER-OAFA | (11h 42m 16.98s , +13d 09m 21.5s) |   C |   180 | 17.9 |        
   19137 | 2023-06-29 01:39:58 |         MASTER-OAFA | (11h 42m 12.15s , +13d 08m 40.0s) |   C |   180 | 17.6 |        
   19581 | 2023-06-29 01:47:22 |         MASTER-OAFA | (11h 38m 17.87s , +11d 38m 32.8s) |   C |   180 | 17.6 |        
   19792 | 2023-06-29 01:50:54 |         MASTER-OAFA | (11h 38m 12.10s , +11d 37m 29.1s) |   C |   180 | 17.9 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230628A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34115
SUBJECT: GRB 230628A: Enhanced Swift-XRT position
DATE:    23/06/29 04:09:47 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 3999 s of XRT Photon Counting mode data and 9 UVOT
images for GRB 230628A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 171.84876, -11.46370 which is equivalent
to:

RA (J2000): 11h 27m 23.70s
Dec (J2000): -11d 27' 49.3"

with an uncertainty of 2.1 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB230628E
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34116
SUBJECT: GRB 230628E: Enhanced Swift-XRT position (Correction to name in GCN 34115)
DATE:    23/06/29 04:37:07 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>

K.L. Page and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT
team:

GCN 34115 incorrectly referred to GRB 230628A; the enhanced position given
was instead for GRB 230628E. We repeat the details here, with the correct
name:

Using 3999 s of XRT Photon Counting mode data and 9 UVOT images for GRB
230628E, we find an astrometrically corrected X-ray position (using the
XRT-UVOT alignment and matching UVOT field sources to the USNO-B1
catalogue): RA, Dec = 171.84876, -11.46370 which is equivalent to:

RA (J2000): 11h 27m 23.70s
Dec (J2000): -11d 27' 49.3"

with an uncertainty of 2.1 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at https://www.swift.ac.uk/xrt_positions/ Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230628E
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34117
SUBJECT: GRB 230628E: Swift-XRT refined Analysis
DATE:    23/06/29 06:42:28 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), M. Capalbi (INAF-IASFPA), M.
Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), D.N. Burrows
(PSU) and P.A. Evans report on behalf of the Swift-XRT team:

We have analysed 6.3 ks of XRT data for GRB 230628E, from 226 s to 22.6
ks after the  BAT trigger. The data are entirely in Photon Counting
(PC) mode. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.85 (+/-0.05).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.94 (+/-0.18). The
best-fitting absorption column is  9.5 (+4.9, -4.3) x 10^20 cm^-2, in
excess of the Galactic value of 4.3 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.4 x 10^-11 (4.1 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      9.5 (+4.9, -4.3) x 10^20 cm^-2
Galactic foreground: 4.3 x 10^20 cm^-2
Excess significance: 2.0 sigma
Photon index:      1.94 (+/-0.18)

If the light curve continues to decay with a power-law decay index of
0.85, the count rate at T+24 hours will be 8.1 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.8 x
10^-13 (3.3 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01177054.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230628E
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34118
SUBJECT: GRB230628E: VLT optical identification of afterglow candidate
DATE:    23/06/29 07:14:44 GMT
FROM:    J. T. Palmerio at Observatoire de Paris - GEPI <jesse.palmerio@obspm.fr>

D. B. Malesani (Radboud Univ. and DAWN/NBI) and J. Palmerio (GEPI / Paris Obs.) report on behalf of the STARGATE collaboration:
 We observed the field of GRB 230628E (Salvaggio et al., GCN 34110) with the ESO VLT UT3 (Melipal) equipped with the X-shooter acquisition camera.
 In a single 30 s exposure acquired in the r band, with mid time June 29.0252 UT (2.17 hr after the GRB), we see a new object, very close to the Swift/XRT position, which is not visible in the Pan-STARRS images of this field. Its coordinates (J2000, calibrated against the Gaia catalog, 0.5" error) are:
 RA = 11:27:23.60
 Dec = -11:27:49.21
 Preliminary photometry (against the Pan-STARRS catalog) yields a magnitude r = 21.2
 We consider this object a strong candidate as the afterglow of GRB 230628E, due to its consistency with the X-ray position and lack of detection in the Pan-STARRS archival images.
 Further observations are in progress. We acknowledge expert support from the observing staff in Paranal, in particular Eleonora Sani (to whom we wish a happy birthday), Thomas Romain (on his last observing night in Paranal), Ditte Slumstrup (who actually discovered the afterglow), and Thomas Rivinius.


GRB_name: GRB230625B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34119
SUBJECT: GRB 230625B: AstroSat CZTI detection
DATE:    23/06/29 09:19:30 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>

P K. Navaneeth (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a GRB 230625B which was also detected by CALET (Trig. 1371713313) and Swift/BAT-GUANO (Ronchini et al., GCN Circ. 34084).

The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2023-06-25 07:28:57.50 UTC. The measured peak count rate associated with the burst is 279 (+55, -14) counts/s above the background in the combined data of all quadrants, with a total of 9279 (+893, -648) counts. The local mean background count rate was 504 (+3, -5) counts/s. Using cumulative rates, we measure a T90 of 65 (+3, -4) s.

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2023-06-25 07:28:57.50 UTC. The measured peak count rate associated with the burst is 266 (+80, -19) counts/s above the background in the combined data of all quadrants, with a total of 7354 (+1143, -1181) counts. The local mean background count rate was 1607 (+5, -6) counts/s. We measure a T90 of 70 (+3, -15) s from the cumulative Veto light curve.

We further report the detection of 2 more bright bursts, with multiple peaks, about 50 s after the first burst reported above had ended. Preliminary analysis shows that these subsequent emission bursts had similar signatures to GRB 230625B and lasted for about 200 s, after which AstroSat entered the South Atlantic Anomaly (SAA) region. We caution that since AstroSat was close to SAA, these bursts may not be related to GRB 230625B.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB230628C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34120
SUBJECT: Fermi GRB 230628C: Global MASTER-Net observations report
DATE:    23/06/29 11:30:37 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-OAGH robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB 230628C ( Fermi GBM team, GCN 34106) errorbox  61791 sec after notice time and 61823 sec after trigger time at 2023-06-29 10:46:57 UT, with upper limit up to  17.1 mag. Observations started at twilight.  The observations began at zenith distance = 27 deg. The sun  altitude  is -16.8 deg. 

The galactic latitude b =  2 deg., longitude l = 73 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2229961

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   61913 | 2023-06-29 10:46:57 |         MASTER-OAGH | (19h 47m 59.92s , +37d 05m 18.1s) |   C |   180 | 17.1 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230628E
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34122
SUBJECT: GRB 230628E - VLT spectroscopic observations
DATE:    23/06/29 13:05:51 GMT
FROM:    J. T. Palmerio at Observatoire de Paris - GEPI <jesse.palmerio@obspm.fr>

J. T. Palmerio (GEPI / Paris Obs. and IAP), D. B. Malesani (Radboud Univ. and DAWN/NBI),  A. Saccardi (GEPI / Paris Obs.), L. Izzo (INAF/OACn & DARK/NBI), P. Schady (Univ. Bath), A. de Ugarte Postigo (OCA) report on behalf of the STARGATE collaboration:

We observed the optical afterglow candidate of GRB 230628E (Malesani et al. GCN 34118) with the ESO VLT UT3 (Melipal) equipped with the X-shooter spectrograph.
Spectroscopy was carried out, covering the wavelength range 3000-21000 AA, and consisting of 4 exposures of 600 s each. The observation mid time was 2023 June 29 at 01:05 UT (~2.7 hours after the GRB).

Only a faint continuum is detected from this source down to ~3700 Angstrom, which allows us to set a redshift upper limit z <~ 2.
We note a possible, very faint emission feature at ~15550 Angstrom but in the absence of other associated emission features, we do not derive a redshift from this.

We acknowledge expert support from the observing staff in Paranal, in particular Eleonora Sani, Thomas Romain, Ditte Slumstrup, and Thomas Rivinius.


GRB_name: GRB230625B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34123
SUBJECT: GRB 230625B: CALET Gamma-Ray Burst Monitor detection
DATE:    23/06/30 04:09:47 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

Y. Asaoka (ICRR),  A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
S. Torii, Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 230625B (Swift/BAT-GUANO Detection: Ronchini et al.,
GCN Circ. 34083; AstroSat CZTI detection: Navaneeth et al., GCN 
Circ. 34119) triggered the CALET Gamma-ray Burst Monitor (CGBM)
at 07:28:45.62 UTC on 25 June 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1371713313/index.html).
The burst signal was seen by all CGBM detectors.

The burst light curve shows multi-peaked structure that starts
at T-2.0 sec. The whole episode was not seen by CGBM because 
the sequence of the HV turn-off started from T+220 sec.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1371713313/

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.


GRB_name: GRB230625B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34126
SUBJECT: IPN triangulation of GRB 230625B (ultra-long)
DATE:    23/06/30 23:54:32 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,

D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team,

E. Burns on behalf of the IPN,

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:

The ultra-long GRB 230625B
(Swift-BAT/GUANO detection: Ronchini et al., GCN Circ. 34084;
AstroSat-CZTI detection: Navaneeth et al., GCN Circ. 34119;
CALET-GBM detection: Asaoka et al., GCN Circ. 34123)
was detected by Konus-Wind, INTEGRAL (SPI-ACS), AstroSat (CZTI),
CALET (GBM triggers 1371713313 and 1371714158), Swift (BAT),
and Mars-Odyssey (HEND) at about 26925 s UT (07:28:45).
The burst was outside the coded field of view of the BAT.

As observed by Konus-Wind, the burst light curve shows a multi-peaked structure with the total duration of ~1100 s.

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ------------------------------
  RA(2000), deg  Dec(2000), deg
 ------------------------------
 Center:
    348.047      +27.385
 Corners:
    359.451      +18.898
    359.209      +18.406
    324.407      +33.245
    323.504      +33.777
 -------------------------------
The error box area is 18.4 sq. deg, and its maximum
dimension is 35.3 deg (the minimum one is 31.4 arcmin).
The Sun distance was about 86 deg.

This box may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB230625_T26937/IPN

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB230625_T26937

A detailed analysis of the Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular.


GRB_name: GRB230701A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34131
SUBJECT: GRB 230701A: Fermi GBM Final Real-time Localization
DATE:    23/07/01 22:55:18 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 22:44:39 UT on 1 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230701A (trigger 709944284.121944 / 230701948).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 115.7, Dec = 43.0 (J2000 degrees, equivalent to J2000 07h 42m, 43d 00'), with a statistical uncertainty of 2.9 degrees.

The angle from the Fermi LAT boresight is 45.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230701948/quicklook/glg_skymap_all_bn230701948.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230701948/quicklook/glg_healpix_all_bn230701948.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230701948/quicklook/glg_lc_medres34_bn230701948.gif


GRB_name: GRB230628E
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34132
SUBJECT: GRB 230628E: ATCA rapid radio follow-up
DATE:    23/07/02 04:53:29 GMT
FROM:    Gemma Anderson at Curtin U <gemma.anderson@curtin.edu.au>

G. E. Anderson (Curtin), J. K. Leung (USyd), A. J. van der Horst (GWU), A. Gulati (USyd), L. Rhodes (Oxford), S. Chastain (UNM) on behalf of the PanRadio GRB collaboration

The Australia Telescope Compact Array (ATCA) rapidly performed observations of the long GRB 230628E (Klingler et al. GCN 34110) at 5.5, 9, 16.7 and 21.2 GHz as part of the Large ATCA â€œPanRadio GRBâ€ follow-up programme C3542 (PI. Anderson). ATCA was on target observing at 2023-06-29 02:11 UT when the source had risen above the horizon, just 3.75 hrs post-burst and observed for 10.5 hrs. There is no radio source coincident with the enhanced XRT position (Page et al. GCN 34116) with 3 sigma upper limits of 44, 39, 54 and 78 microJy/beam at 5.5, 9.0, 16.7 and 21.2 GHz, respectively. Further observations are planned.

We thank the CSIRO Space and Astronomy staff for supporting these observations and maintaining the ATCA rapid-response observing mode.

We acknowledge the Gomeroi people as the traditional owners of the Observatory site. The Australia Telescope Compact Array is part of the Australia Telescope National Facility (https://ror.org/05qajvd42) which is funded by the Australian Government for operation as a National Facility managed by CSIRO.


GRB_name: GRB230702A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34133
SUBJECT: GRB 230702A: Fermi GBM Final Real-time Localization
DATE:    23/07/02 12:50:19 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 12:38:53 UT on 2 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230702A (trigger 709994338.06172 / 230702527).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 92.6, Dec = -27.4 (J2000 degrees, equivalent to J2000 06h 10m, -27d 23'), with a statistical uncertainty of 4.2 degrees.

The angle from the Fermi LAT boresight is 32.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230702527/quicklook/glg_skymap_all_bn230702527.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230702527/quicklook/glg_healpix_all_bn230702527.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230702527/quicklook/glg_lc_medres34_bn230702527.gif


GRB_name: GRB230628E
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34134
SUBJECT: GRB 230628E: Swift-BAT refined analysis
DATE:    23/07/02 13:03:50 GMT
FROM:    Sibasish Laha at GSFC <sibasish.laha@nasa.gov>

T. Parsotan (GSFC/UMBC), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Sakamoto (AGU),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230628E (trigger #1177054)
(Salvaggio et al., GCN Circ. 34110).  The BAT ground-calculated position is
RA, Dec = 171.851, -11.430 deg which is
   RA(J2000)  =  11h 27m 24.3s
   Dec(J2000) = -11d 25' 46.5"
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 41%.

The BAT  light curve shows a complex structure with a duration of ~ 15 sec.
T90 (15-350 keV) is 4.72 +- 1.08 sec (estimated error including systematics).

The time-averaged spectrum from T-0.50 to T+4.81 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.45 +- 0.30.  The fluence in the 15-150 keV band is 3.3 +- 0.6 x 10^-07 erg/cm2.
The 1-sec peak photon flux measured from T+0.33 sec in the 15-150 keV band
is 1.1 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1177054/BA/


GRB_name: GRB230628E
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34135
SUBJECT: GRB 230628E: Swift/UVOT Detection
DATE:    23/07/02 18:36:09 GMT
FROM:    Samantha Oates at University of Birmingham <samantha.oates@alumni.ucl.ac.uk>

S. R. Oates (U. Birmingham) and N. Klingler (NASA-GSFC/UMBC/CRESST II)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230628E
221 s after the BAT trigger (Klingler et al., GCN Circ. 34110).
A source consistent with the XRT position (Page et al., GCN Circ. 34116)
and the optical position (Malesani et al., GCN Circ. 34118)
is detected in the initial UVOT exposures.

Preliminary detections and 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white (FC)         221          371          167         20.10 +/- 0.20
wh                 501         1194          223         20.69 +/- 0.34       
v                  379         1243           68        >19.1
b                  477         1170           78        >19.9
u                  452         1145           78        >19.6
w1                 428         1120           78        >19.4
m2                1249         1269           19        >18.2
w2                 700          720           19        >18.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.040 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB220623A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34139
SUBJECT: Konus-Wind detection of GRB 220623A
DATE:    23/07/03 19:54:02 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

D. Svinkin, D. Frederiks, A. Lysenko, A. Ridnaia,
Y. Temiraev, A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long-duration GRB 220623A
(MAXI-GSC detection: Hagiwara et al., GCN 34068)
was detected by Konus-Wind (KW) in the waiting mode.

A Bayesian block analysis of the KW waiting mode data
in the 20-1500 keV band reveals a multi-peaked structure
which starts at ~T0 and ends at ~T0+580 s,
where T0 = T0(MAXI) = 07:23:37 UT.

The KW light curve of this burst is available at
http://www.ioffe.ru/LEA/GRBs/GRB230623A/

Modelling a time-integrated spectrum of the burst
by a power law (PL) model dN/dE ~ E^alpha
yields alpha = -2.18(-0.04,+0.05).

The spectrum near the peak count rate,
measured from T0+43.303 s to T0+75.687 s,
can be described by a power law with exponential cutoff (CPL) model
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with alpha = -1.58(-0.13, +0.15) and Ep = 243(-57,+141) keV.

The total burst fluence is 5.77(-0.34,+0.52)x10^-5 erg/cm^2,
and the 2.944 s peak energy flux is 6.08(-0.97,+1.40)x10^-7 erg/cm^2.
(both in the 20 keV - 10 MeV energy range).

All the quoted errors are estimated at the 68% confidence level.
All the presented results are preliminary.


GRB_name: GRB230328B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34141
SUBJECT: GRB 230328B: LBT detection of the likely host galaxy
DATE:    23/07/04 14:14:34 GMT
FROM:    Andrea Rossi at INAF <andrea.rossi@inaf.it>

A. Rossi, E. Maiorano, and E. Palazzi (INAF-OAS) report on behalf of the CIBO collaboration:

We observed the field of the long GRB 230328B detected by Fermi-GBM  (Fermi GBM Team, GCN 33526; Dalessi et al., GCN 33531), Swift-BAT (Gropp et al., GCN 33527), AstroSat-CZTI (Waratkar et al., GCN 33532), GRBAlpha (Dafcikova et al., GCN 33543), and Konus-Wind (Svinkin et al., GCN 33544). We obtained 20 min of g'- and r'-band imaging with the LBC camera mounted on LBT (Mt Graham, AZ, USA) on 2023-06-23, ~3 months after the burst trigger. Observations were performed under mediocre weather conditions with a strong SW wind and thus an average seeing of ~2".

At the location of the optical afterglow (Pankov et al., GCN 33528; Belkin et al., GCN 33530; Lu et al., GCN 33534; Catapano et al., GCN 33535; Suresh et al., GCN 33536; Adami et al., GCN 33537; Gompertz et al., GCN 33538; Komesh et al., GCN 33539; Kumar et al., GCN 33547; Kugel et al., GCN 33550; Siegel et al., 33556; Pozanenko et al., GCN 33559), we detect a faint source which is likely the GRB host galaxy. We measure the following AB magnitudes:

g 24.2 +- 0.3
r 23.8 +- 0.2

calibrated against PanSTARRS field stars, and not corrected for the foreground Galactic extinction.

We acknowledge the excellent support from the LBTO and LBT-INAF staff, particularly D. Thompson, D. Gonzalez Huerta, F. Cusano and D. Paris, in obtaining these observations.


GRB_name: GRB230626A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34143
SUBJECT: GRB 230626A: VZLUSAT-2 detection
DATE:    23/07/04 16:50:13 GMT
FROM:    Marianna DafÄÃ­kovÃ¡ at Masaryk University <500025@mail.muni.cz>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory),  N. Werner  (Masaryk U.), M. Ohno (Hiroshima U.),  L. Meszaros, B. Csak (Konkoly Observatory), H. Takahashi (Hiroshima U.), F. Munz , M. Topinka, F. Hroch, N. Husarikova, J.-P. Breuer (Masaryk U.), J. Hudec, J. Kapus, M. Frajt, M. Rezenov (Spacemanic s.r.o), R. Laszlo (Needronix), G. Galgoczi (Wigner Research Center/Eotvos U.), N. Uchida (ISAS/JAXA), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), Y. Fukazawa, K. Hirose, H. Matake (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), K. Torigoe (Hiroshima U.), P. Svoboda, V. Daniel, J. Dudas, M. Junas, J. Gromes (VZLU), I. Vertat (FEL ZCU)  -- the VZLUSAT-2/GRB payload collaboration.

The long duration GRB 230626A (Fermi/GBM detection: GCN 34094; GRBAlpha detection: GCN 34099; GECAM-B detection: trigger no. 198; Konus/Wind detection at 2023-06-26 14:30:27.440 UT) was detected by the GRB detector on board of the VZLUSAT-2 3U CubeSat (https://www.vzlusat2.cz/en/).

The data acquisition was performed by the GRB detector unit no. 1. The detection was confirmed at the peak time 2023-06-26 14:30:32 UTC. The T90 duration measured by VZLUSAT-2 is 13 s and the significance during T90 reaches 19 sigma.

The light curve obtained by VZLUSAT-2 is available here:
https://vzlusat2.konkoly.hu/static/share/GRB230626A_GCN_VZLUSAT2.pdf

All VZLUSAT-2 detections are listed at: https://monoceros.physics.muni.cz/hea/VZLUSAT-2/
The GRB detectors on VZLUSAT-2 are a demonstration payload for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). Two GRB modules of VZLUSAT-2 are placed in a perpendicular manner and each consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~30 keV to ~1000 keV. VZLUSAT-2 was launched on 2022 January 13 from Cape Canaveral.


GRB_name: GRB230625A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34149
SUBJECT: GRB 230625A: Detection by GRID
DATE:    23/07/06 14:32:09 GMT
FROM:    GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn>

Chenyu Wang and Zirui Yang report on behalf of the GRID Collaboration:

The long-duration GRB 230625A (Fermi GBM detection: GCN Circular 34080) was observed with GRID-03B.

The detection was confirmed at the trigger time 2023-06-25T18:23:56.7 UTC. The T90 duration measured with GRID is 59.0 s.

A brief introduction to GRID can be found at https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4.


GRB_name: GRB230707A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34156
SUBJECT: GRB 230707A: Fermi GBM Final Real-time Localization
DATE:    23/07/07 03:34:19 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 03:22:51 UT on 7 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230707A (trigger 710392976.959644 / 230707141).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 173.9, Dec = -17.1 (J2000 degrees, equivalent to J2000 11h 35m, -17d 06'), with a statistical uncertainty of 2.5 degrees.

The angle from the Fermi LAT boresight is 67.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230707141/quicklook/glg_skymap_all_bn230707141.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230707141/quicklook/glg_healpix_all_bn230707141.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230707141/quicklook/glg_lc_medres34_bn230707141.gif


GRB_name: GRB230707A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34157
SUBJECT: Fermi GRB 230707A: Global MASTER-Net observations report
DATE:    23/07/07 04:15:50 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-OAGH robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB 230707A ( Fermi GBM team, GCN 34156) errorbox  174 sec after notice time and 210 sec after trigger time at 2023-07-07 03:26:21 UT, with upper limit up to  18.0 mag. Observations started at twilight.  The observations began at zenith distance = 71 deg. The sun  altitude  is -11.9 deg. 

MASTER-OAFA robotic telescope  located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 230707A errorbox  804 sec after notice time and 840 sec after trigger time at 2023-07-07 03:36:52 UT, with upper limit up to  12.3 mag. The observations began at zenith distance = 87 deg. The sun  altitude  is -73.8 deg. 

The galactic latitude b = 42 deg., longitude l = 279 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2234493

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     230 | 2023-07-07 03:26:21 |         MASTER-OAGH | (11h 31m 43.96s , -18d 19m 29.8s) |   C |    40 | 16.8 |        
     451 | 2023-07-07 03:29:42 |         MASTER-OAGH | (11h 31m 38.19s , -18d 20m 47.6s) |   C |    80 | 17.2 |        
     916 | 2023-07-07 03:36:42 |         MASTER-OAGH | (11h 35m 36.07s , -17d 26m 31.7s) |   C |   170 | 17.8 |        
     906 | 2023-07-07 03:36:52 |         MASTER-OAFA | (11h 33m 57.32s , -16d 58m 43.3s) |   C |   130 | 12.3 |        
    1251 | 2023-07-07 03:42:12 |         MASTER-OAGH | (11h 35m 36.41s , -17d 28m 18.2s) |   C |   180 | 18.0 |        
    1592 | 2023-07-07 03:47:53 |         MASTER-OAGH | (11h 31m 07.26s , -16d 16m 23.9s) |   C |   180 | 17.7 |        
    1934 | 2023-07-07 03:53:35 |         MASTER-OAGH | (11h 39m 30.22s , -16d 16m 43.2s) |   C |   180 | 18.0 |        
    2274 | 2023-07-07 03:59:15 |         MASTER-OAGH | (11h 31m 16.26s , -16d 16m 40.2s) |   C |   180 | 17.7 |        
    2620 | 2023-07-07 04:05:01 |         MASTER-OAGH | (11h 39m 28.83s , -16d 16m 03.1s) |   C |   180 | 18.0 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230707A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34159
SUBJECT: GRB 230707A: Swift/BAT-GUANO arcminute localization of a burst
DATE:    23/07/07 11:21:40 GMT
FROM:    Aaron Tohuvavohu at University of Toronto <aaron.tohu@gmail.com>

Aaron Tohuvavohu (U Toronto), James DeLaunay (U Alabama), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC)  report:

Swift/BAT did not localize GRB 230707A onboard (T0: 2023-07-07T03:22:51 UTC, Fermi/GBM GCN 34156).

The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.

The burst is ~15 s in duration as seen by BAT.

In ground analysis of the available data, we find the position of the burst with SNR 10.0 in the image domain.
The BAT position is RA, Dec = 171.4759 -21.5125, which is:
    RA (J2000)     11h 25m 54.22s
    Dec (J2000)  -21d 30' 45.0"
with an estimated uncertainty of 2 arcminutes.

XRT and UVOT follow-up has been requested.
Results of follow-up observations will be reported in future circulars.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/


GRB_name: GRB230707A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34160
SUBJECT: GRB 230707A: Swift ToO observations
DATE:    23/07/07 12:28:56 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the Swift/BAT-GUANO GRB 230707A. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021587

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the Swift/BAT-GUANO event. Any X-ray source
considered to be a probable afterglow candidate will be reported via a 
GCN Circular after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230707A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34162
SUBJECT: GRB 230707A: Fermi GBM Detection
DATE:    23/07/07 17:52:03 GMT
FROM:    Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>

P. Veres and C. Meegan (both UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 03:22:51.96 UT on 07 July 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230707A (trigger 710392976/230707141),
which was also detected by the Swift/BAT-GUANO (Tohuvavohu et al.
2023, GCN 34159).
The Fermi GBM Final Real-time Localization (GCN 34156) is consistent
with the Swift position.
The angle from the Fermi LAT boresight is 63 degrees.

The GBM light curve consists of multiple pulses with a duration (T90)
of about 29 s (50-300 keV). The time-averaged spectrum
from T0-2.8 to T0+30.0 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.77 +/- 0.08 and the cutoff energy,
parameterized as Epeak, is 121 +/- 7 keV.

The event fluence (10-1000 keV) in this time interval is
(6.9 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.5 s in the 10-1000 keV band is 6.5 +/- 0.3 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 110 +/- 10 keV, alpha = -0.7 +/- 0.1 and beta = -2.5 +/- 0.2.


The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB230707B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34165
SUBJECT: GRB 230707B: Fermi GBM Final Real-time Localization
DATE:    23/07/07 18:56:58 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 18:46:20 UT on 7 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230707B (trigger 710448385.289496 / 230707782).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 28.5, Dec = -41.3 (J2000 degrees, equivalent to J2000 01h 53m, -41d 17'), with a statistical uncertainty of 2.2 degrees.

The angle from the Fermi LAT boresight is 83.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230707782/quicklook/glg_skymap_all_bn230707782.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230707782/quicklook/glg_healpix_all_bn230707782.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230707782/quicklook/glg_lc_medres34_bn230707782.gif


GRB_name: GRB230707A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34168
SUBJECT: GRB 230707A: Swift-XRT observations
DATE:    23/07/08 09:04:40 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

A. Tohuvavohu (U. Toronto), A.P. Beardmore (U. Leicester), J.P. Osborne
(U. Leicester), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC &
INAF-OAR), B. Sbarufatti (INAF-OAB), D.N. Burrows (PSU), J. D. Gropp
(PSU) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT
team:

Swift-XRT has performed follow-up observations of the
Swift/BAT-GUANO-detected burst GRB 230707A, collecting 4.7 ks of Photon
Counting (PC) mode data between T0+32.7 ks and T0+51.0 ks. 

No X-ray sources have been detected consistent with being within 197
arcsec of the Swift/BAT-GUANO position. The 3-sigma upper limit in the
field ranges from ~0.002 to ~0.003 ct s^-1, corresponding to a 0.3-10
keV observed flux of 9.4e-14 to 1.3e-13 erg cm^-2 s^-1 (assuming a
typical GRB spectrum).

Three uncatalogued sources were detected too far from the GRB position
to be likely afterglow candidates.

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00021587.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230707B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34169
SUBJECT: GRB 230707B: Swift/BAT-GUANO detection of a burst outside the coded FOV
DATE:    23/07/08 12:27:24 GMT
FROM:    Jimmy DeLaunay at University of Alabama  <delauj2@gmail.com>

James DeLaunay (U Alabama), Aaron Tohuvavohu (U Toronto), Samuele Ronchini (PSU), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: 

Swift/BAT did not localize GRB 230707B onboard (T0: 2023-07-07T18:46:20.29 UTC, Fermi trig 710120768, CALET trig 1372790743, INTEGRAL trig 10313) 

The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. 

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 12.0 in a 16.384 s analysis time bin, starting at T0. 

The burst is ~100 s in duration as seen by BAT. 

NITRATES results are consistent with a burst coming from outside the FOV, with DeltaLLHOut of -7 and are consistent with Fermi GBM's localization (GCN 34165).

See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut. 

GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. 

A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/


GRB_name: GRB230628C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34171
SUBJECT: GRB 230628C: GRID Detection
DATE:    23/07/08 14:30:08 GMT
FROM:    GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn>

Chenyu Wang and Zirui Yang report on behalf of the GRID Collaboration:

The long-duration GRB 230628C (Fermi GBM detection: GCN Circular 34106) was observed with GRID-07.

The detection was confirmed at the trigger time 2023-06-28T17:36:22.8 UTC. The T90 duration measured with GRID is 49.0 s.

A brief introduction to GRID can be found at https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4.


GRB_name: GRB230709A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34174
SUBJECT: Swift Trigger 1178410: possible GRB 230709A
DATE:    23/07/09 09:30:54 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>


A. Y. Lien (U Tampa), C. Gronwall (PSU) and K. L. Page (U Leicester)
report on behalf of the Neil Gehrels Swift Observatory Team:

The Swift Burst Alert Telescope (BAT) has triggered on a new event 
(trigger=1178410) and Swift has slewed to the location of this trigger. The 
trigger time is believed to be no earlier than 07:30 UT. Given a brief gap in the
TDRSS coverage we are unable to confirm the nature, location, or exact time of this 
trigger until the full data have been downloaded, in approximately by around 10:00 
UT. 

Limited XRT and UVOT data have been received. No counterpart is detected; however,
given the location of the image centre, we infer that the BAT position must have
been around RA,Dec = 162.052, -22.624 degrees (J2000), with an uncertainty of 12'. 

Burst Advocate for this burst is A. Y. Lien (yarleen AT gmail.com). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB230709B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34179
SUBJECT: GRB 230709B: BALROG localization (Fermi Trigger 710614579 / GRB 230709706)
DATE:    23/07/09 17:19:33 GMT
FROM:    Jochen Greiner at MPE <jcgrog@mpe.mpg.de>

B. Biltzinger, T. Preis, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
710614579 at 16:56:14 on 09 July 2023 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 87.0+/-1.2 deg
Decl.(2000.0) = -3.0+/-0.8 deg
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB230709706/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB230709706/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB230709706/json

                        


GRB_name: GRB230709C
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34187
SUBJECT: GRB 230709C: BALROG localization (Fermi Trigger 710617111 / GRB 230709735)
DATE:    23/07/09 22:19:05 GMT
FROM:    Jochen Greiner at MPE <jcgrog@mpe.mpg.de>

T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
710617111 at 17:38:26 on 09 July 2023 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 267.1+/-6.5 deg
Decl.(2000.0) = -71.4+/-1.1 deg
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB230709735/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB230709735/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB230709735/json

                        


GRB_name: GRB230703A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34188
SUBJECT: GRB 230703A detected with multiple GRID detectors
DATE:    23/07/10 06:21:09 GMT
FROM:    GRID Student Team at Tsinghua University <grid@tsinghua.edu.cn>

Chenyu Wang and Zirui Yang report on behalf of the GRID Collaboration:

The long-duration GRB 230703A (Fermi GBM Trigger Number bn230703954) was also detected with three GRID detectors, GRID-03B, GRID-04, and GRID-07, onboard two different CubeSats. 

The event was triggered by GRID on 2023-07-03 at 22:53:07.4 UTC.  The GRID light curves show a two-pulse temporal structure, each with a fast rise exponential decay like shape. The measured burst duration (T90) in the 30-2000 keV range is approximately 18.6 +/- 1.2 seconds. The GRB position derived from the GRID data is consistent with the burst location reported by Fermi/GBM (GCN Notice #710117592). An origin from Cygnus X-1 can be ruled out as the source is occulted by Earth in the view of GRID-03B. Further analysis of the data is currently in progress. 

GRID is a student-led project to monitor the transient gamma-ray sky with multiple detectors onboard different nanosatellites in the era of multi-messenger astronomy. For more information about GRID, please refer to the following references: https://doi.org/10.1007/s10686-019-09636-w and https://doi.org/10.1007/s10686-021-09819-4.


GRB_name: GRB230707B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34189
SUBJECT: GRB 230707B: CALET Gamma-Ray Burst Monitor detection
DATE:    23/07/10 07:10:03 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

S. Torii (Waseda U), A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), Y. Akaike, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 230707B (Fermi GBM Final Real-time Localization: 
Fermi GBM team, GCN Circ. 34165; Swift/BAT-GUANO detection: 
DeLaunay et al., GCN Circ. 34169) triggered the CALET Gamma-ray
Burst Monitor (CGBM) at 18:46:18.95 UTC on 7 July 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1372790743/index.html).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a multi-peaked structure that starts
at T+1.0 sec, peaks at T+82.1 sec, and ends at T+108.1 sec.
The T90 and T50 durations measured by the SGM data are 94.6 +/- 1.6 sec
and 52.1 +/- 1.2 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1372790743/

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.


GRB_name: GRB230710A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34196
SUBJECT: GRB 230710A: Fermi GBM Final Real-time Localization
DATE:    23/07/10 20:00:34 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 19:50:00 UT on 10 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230710A (trigger 710711405.793774 / 230710826).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 26.3, Dec = -17.4 (J2000 degrees, equivalent to J2000 01h 45m, -17d 23'), with a statistical uncertainty of 4.8 degrees.

The angle from the Fermi LAT boresight is 15.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230710826/quicklook/glg_skymap_all_bn230710826.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230710826/quicklook/glg_healpix_all_bn230710826.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230710826/quicklook/glg_lc_medres34_bn230710826.gif


GRB_name: GRB230707B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34197
SUBJECT: GRB 230707B: Fermi GBM Observation
DATE:    23/07/10 20:00:51 GMT
FROM:    sumanbala2210@gmail.com

S. Bala (USRA) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 18:46:20.29 UT on 07 July 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230707B (trigger 710448385/230707782).
which was also detected by Swift/BAT-GUANO (James DeLaunay et al. 2023, GCN 34169)
and CALET GBM (S. Torii et al. 2023, GCN 34189). The Fermi GBM Final Real-time Localization
was reported at GCN 34165.

The angle from the Fermi LAT boresight is 83 degrees.

The GBM light curve is long and consists of many peaks with a duration (T90)
of 99.6 s (50-300 keV). The time-averaged spectrum
from T0-2.3 to T0+117.5 s is best fit by
a Band function with Epeak = 143 +/- 5 keV,
alpha = -0.63 +/- 0.04, and beta = -2.15 +/- 0.05.

The event fluence (10-1000 keV) in this time interval is
(5.4 +/- 0.1)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+80 s in the 10-1000 keV band is 5.3 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB230709C
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34198
SUBJECT: GRB 230709C: Fermi GBM Final Localization
DATE:    23/07/10 20:07:49 GMT
FROM:    Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>


The Fermi GBM team reports the detection of a likely SHORT GRB

"At 17:38:26.82 UT on 09 July 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230709C (trigger 710617111/230709735), which 
initially was classified as a non-GRB trigger by the flight software.

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 267.56, Dec = -70.47 (J2000 degrees, equivalent to J2000 17h 50m, -70d 28'),
with a statistical uncertainty of 1.44 degrees.

The angle from the Fermi LAT boresight is 131 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230709735/quicklook/glg_skymap_all_bn230709735.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230709735/quicklook/glg_healpix_all_bn230709735.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230709735/quicklook/glg_lc_medres34_bn230709735.gif"


GRB_name: GRB230709C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34199
SUBJECT: GRB 230709C: Fermi GBM Detection
DATE:    23/07/10 20:12:24 GMT
FROM:    Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>


P. Veres  and C. Meegan (both UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 17:38:26.82 UT on 09 July 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230709C (trigger 710617111/230709735).

The on-ground calculated location, using the Fermi GBM trigger data (GCN #34198) is consistent with the location reported by Preis et al., GCN #34187.

The GBM light curve consists of a single emission episode with a duration (T90)
of about 0.19 s (50-300 keV). The time-averaged spectrum
from T0-0.06 to T0+0.19 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -0.01 +/- 0.07 and the cutoff energy,
parameterized as Epeak, is 1050 +/- 50 keV.

The event fluence (10-1000 keV) in this time interval is
(6.3 +/- 0.1)E-06 erg/cm^2. The 64-ms peak photon flux measured
starting from T0+0.0 s in the 10-1000 keV band is 58 +/- 3 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB230709B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34200
SUBJECT: GRB 230709B: GRBAlpha detection
DATE:    23/07/11 07:36:50 GMT
FROM:    Jakub Ripa <ripa.jakub@gmail.com>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), yyT. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.

The long-duration GRB 230709B (Fermi/GBM detection: GCN Circ. 34179) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023; arXiv:2302.10048).

The detection was confirmed at the peak time 2023-07-09 16:56:15 UTC. The T90 duration measured by GRBAlpha is 6 s and the overall significance during T90 reaches 9 sigma.

The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB230709B_GCN.pdf

All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/ GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.


GRB_name: GRB230709C
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34201
SUBJECT: GRB 230709C: GRBAlpha detection
DATE:    23/07/11 07:39:09 GMT
FROM:    Jakub Ripa <ripa.jakub@gmail.com>

M. Dafcikova, J. Ripa (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz , M. Topinka, M. Kolar, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal,  A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), yyT. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory),  T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.

The short-duration GRB 230709C (Fermi/GBM detection: GCN Circ. 34187; AstroSat detection: GCN Circ. 34191) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023; arXiv:2302.10048).

The detection was confirmed at the peak time 2023-07-09 17:38:26 UTC. The light curve observed by GRBAlpha shows a spike within 1 s bin where the SNR reaches 9 sigma.

The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB230709C_GCN.pdf

All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/ GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.


GRB_name: GRB230712A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34204
SUBJECT: GRB 230712A: Fermi GBM Final Real-time Localization
DATE:    23/07/12 00:49:51 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely SHORT GRB

At 00:39:13 UT on 12 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230712A (trigger 710815158.21058 / 230712027).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 153.8, Dec = 28.5 (J2000 degrees, equivalent to J2000 10h 15m, 28d 30'), with a statistical uncertainty of 19.6 degrees.

The angle from the Fermi LAT boresight is 73.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230712027/quicklook/glg_skymap_all_bn230712027.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230712027/quicklook/glg_healpix_all_bn230712027.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230712027/quicklook/glg_lc_medres34_bn230712027.gif


GRB_name: GRB230707A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34205
SUBJECT: GRB 230707A: Swift/BAT-GUANO position correction
DATE:    23/07/12 01:58:42 GMT
FROM:    Aaron Tohuvavohu at University of Toronto <aaron.tohu@gmail.com>

Aaron Tohuvavohu (U Toronto), Dmitry Svinkin (Ioffe Institute) report:

The prior reporting of the arcminute localization of GRB 230707A (GCN 34159) is incorrect.

The GRB signal detected and localized by BAT-GUANO is real, and correctly localized to arcminute precision in the instrument frame.
However, an incorrect spacecraft attitude quaternion was used for conversion from instrument to celestial coordinates.

The corrected BAT position for this burst is:
RA, Dec =  173.1992 -16.4121, which is:
    RA (J2000)     11h 32m 47.81s
    Dec (J2000)  -16d 24' 43.6"
with an estimated uncertainty of 2 arcminutes.

This position is 5.35 degrees from the position reported in GCN 34159.
I apologize for the error, and gratefully acknowledge the critical support from IPN teammates in identifying this discrepancy.

The source of the error has been identified and corrections will be implemented.
Previous BAT localizations have not been affected by this error.


GRB_name: GRB230712B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34207
SUBJECT: GRB 230712B: Fermi GBM Final Localization
DATE:    23/07/12 21:30:17 GMT
FROM:    Joshua Wood at NASA/MSFC <joshua.r.wood@nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

"At 20:49:57.21 UT on 12 July 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230712B (trigger 710887802/230712868).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 351.15, Dec = -42.61 (J2000 degrees, equivalent to J2000 23h 24m, -42d 36'),
with a statistical uncertainty of 5.38 degrees.

The angle from the Fermi LAT boresight is 31 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230712868/quicklook/glg_skymap_all_bn230712868.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230712868/quicklook/glg_healpix_all_bn230712868.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230712868/quicklook/glg_lc_medres34_bn230712868.gif"


GRB_name: GRB170817A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34208
SUBJECT: IceCube-230708A: Upper limits from Swift/BAT-GUANO
DATE:    23/07/13 03:09:49 GMT
FROM:    Samuele Ronchini at PSU <sjs8171@psu.edu>

Samuele Ronchini (PSU), Gayathri Raman (PSU), Aaron Tohuvavohu (U Toronto), James DeLaunay (U Alabama), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report:

The neutrino candidate (GCN 34203) was inside the coded BAT field of view.

The IceCube notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1).

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 90 seconds of BAT event-mode data from [-45,+45] seconds around the time of the burst. All the requested event mode data was delivered to the ground.

Using the NITRATES analysis (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), we searched for emission on 8 timescales from 0.128s to 16.384s in the interval [-20,+20] seconds around the merger time. We find no evidence for a signal, and derive the following upper limits.

We quote the 5-sigma flux upper limits in the 15-350 keV band, considering IceCube localization, for four spectral templates (soft, normal, and hard GRB-like templates described in [arXiv:1612.02395], and spectral shape from GRB170817A [arXiv:1710.05446]) and for four time bins. 
In units of 10^-8 erg/s/cm^2:

Bin duration (s) | hard normal soft GRB 170817A
---------------------------------------------------- 
0.256    | 10.4 15.0 13.8 15.9
1.024    | 5.3  7.7  7.1  8.1
4.096    | 2.9  4.2  3.8  4.4
16.384     | 1.8  2.6  2.4  2.8


The upper limits as function of sky position are plotted here:
https://doi.org/10.5281/zenodo.8141103

The corresponding fits file can be found here:
https://doi.org/10.5281/zenodo.8140900

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/


GRB_name: GRB230709C
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34209
SUBJECT: GRB 230709C: Swift/BAT-GUANO detection of a short burst outside the coded FOV
DATE:    23/07/13 03:09:57 GMT
FROM:    Samuele Ronchini at PSU <sjs8171@psu.edu>

Samuele Ronchini (PSU), James DeLaunay (U Alabama), Aaron Tohuvavohu (U Toronto), Gayathri Raman (PSU), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report: 

Swift/BAT did not localize GRB 230709C onboard (T0: 2023-07-09T17:38:26.82 UTC, Fermi trig 710617111) 

The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground. 

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), performed on the temporal window [T0-20 s, T0+20 s], detects the burst with a sqrt(TS) of 38.3 in a 0.256 s analysis time bin, starting at T0-0.064. 

NITRATES results are consistent with a burst coming from outside the FOV, with DeltaLLHOut of -32.55 and are consistent with Fermi GBM's localization (GCN 34198).

See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut. 

GUANO is a fully autonomous, extremely low latency, spacecraft commanding pipeline designed for targeted recovery of BAT event mode data around the times of compelling astrophysical events to enable more sensitive GRB searches. 

A live reporting of Swift/BAT event data recovered by GUANO can be found at: https://www.swift.psu.edu/guano/


GRB_name: GRB230703A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34210
SUBJECT: GRB 230703A: CALET Gamma-Ray Burst Monitor detection
DATE:    23/07/13 06:33:14 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

Y. Akaike (Waseda U), A. Yoshida, T. Sakamoto, S. Sugita (AGU), 
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA),
Y. Asaoka (ICRR), S. Torii, K. Kobayashi (Waseda U),
Y. Shimizu, T. Tamura (Kanagawa U), N. Cannady (GSFC/UMBC),
M. L. Cherry (LSU), S. Ricciarini (U of Florence),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 230703A (Fermi GBM Trigger Number 710117592;
GRID detection: Wang et al., GCN Circ. 34188) triggered the 
CALET Gamma-ray Burst Monitor (CGBM) at 22:53:04.92 UTC 
on 3 July 2023
(http://cgbm.calet.jp/cgbm_trigger/flight/1372459956/index.html).
The burst signal was seen by all CGBM detectors.

The burst light curve shows a double-peaked structure that starts
at T+2.1 sec, peaks at T+4.0 sec, and ends at T+17.5 sec.
The T90 and T50 durations measured by the SGM data are 13.5 +/- 0.6 sec
and 7.9 +/- 0.4 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1372459956/

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.


GRB_name: GRB230709B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34211
SUBJECT: GRB 230709B: CALET Gamma-Ray Burst Monitor detection
DATE:    23/07/13 06:46:38 GMT
FROM:    Yuta Kawakubo at Louisiana State University <kawakubo1@lsu.edu>

K. Kobayashi (Waseda U), A. Yoshida, T. Sakamoto, 
S. Sugita (AGU), Y. Kawakubo (LSU), K. Yamaoka (Nagoya U),
S. Nakahira (JAXA), Y. Asaoka (ICRR), S. Torii, 
Y. Akaike (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU), 
S. Ricciarini (U of Florence), P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The long GRB 230709B (Fermi-GBM Trigger 710614579; 
Fermi-GBM BALROG localization: Biltzinger et al., GCN Circ 34179;
GRBAlpha detection: Dafcikova et al., GCN Circ 34200) was detected
in the ground analysis of the CALET Gamma-ray Burst Monitor (CGBM)
data around 16:56:14.47 UTC on 9 July 2023 (referenced to 
Fermi-GBM Trigger 710614579). 
The burst signal was seen by HXM1 and SGM.

The burst light curve shows a single pulse that starts
at T+0.3 sec, peaks at T+3.5 sec, and ends at T+11.3 sec.
The T90 and T50 durations measured by the SGM data are 
9.9 +/- 0.6 sec and 5.4 +/- 1.1 sec (40-1000 keV), respectively.

The ground-processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1372956935/index.html

The CALET data used in this analysis are provided by
the Waseda CALET Operation Center located at Waseda University.


GRB_name: GRB230713A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34214
SUBJECT: GRB 230713A: Fermi GBM Final Real-time Localization
DATE:    23/07/14 00:09:48 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 23:59:05 UT on 13 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230713A (trigger 710985550.945368 / 230713999).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 122.8, Dec = 43.3 (J2000 degrees, equivalent to J2000 08h 11m, 43d 17'), with a statistical uncertainty of 5.5 degrees.

The angle from the Fermi LAT boresight is 86.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230713999/quicklook/glg_skymap_all_bn230713999.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230713999/quicklook/glg_healpix_all_bn230713999.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230713999/quicklook/glg_lc_medres34_bn230713999.gif


GRB_name: GRB230713A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34216
SUBJECT: Fermi GRB 230713A: Global MASTER-Net observations report
DATE:    23/07/14 19:03:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 230713A ( Fermi GBM team, GCN 34214) errorbox  67003 sec after notice time and 67036 sec after trigger time at 2023-07-14 18:36:22 UT, with upper limit up to  16.7 mag. Observations started at twilight.  The observations began at zenith distance = 72 deg. The sun  altitude  is -11.0 deg. 

The galactic latitude b = 33 deg., longitude l = 177 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2239056

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   67127 | 2023-07-14 18:36:22 |      MASTER-Tavrida | (08h 33m 27.83s , +48d 28m 54.8s) |   C |   180 | 16.0 |        
   67321 | 2023-07-14 18:39:36 |      MASTER-Tavrida | (08h 03m 26.04s , +46d 34m 53.8s) |   C |   180 | 15.2 |        
   67514 | 2023-07-14 18:42:49 |      MASTER-Tavrida | (08h 14m 58.75s , +46d 34m 49.7s) |   C |   180 | 15.7 |        
   67706 | 2023-07-14 18:46:02 |      MASTER-Tavrida | (08h 21m 20.69s , +48d 29m 25.6s) |   C |   180 | 16.5 |        
   67899 | 2023-07-14 18:49:14 |      MASTER-Tavrida | (08h 33m 32.63s , +48d 29m 03.2s) |   C |   180 | 16.7 |        
   68091 | 2023-07-14 18:52:26 |      MASTER-Tavrida | (08h 25m 36.83s , +46d 34m 32.3s) |   C |   180 | 16.6 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230715A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34217
SUBJECT: GRB 230715A: Fermi GBM Final Real-time Localization
DATE:    23/07/15 01:53:35 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 01:43:15 UT on 15 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230715A (trigger 711078200.940406 / 230715072).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 117.8, Dec = 46.0 (J2000 degrees, equivalent to J2000 07h 51m, 46d 00'), with a statistical uncertainty of 8.1 degrees.

The angle from the Fermi LAT boresight is 78.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230715072/quicklook/glg_skymap_all_bn230715072.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230715072/quicklook/glg_healpix_all_bn230715072.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230715072/quicklook/glg_lc_medres34_bn230715072.gif


GRB_name: GRB230717A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34220
SUBJECT: GRB 230717A: Fermi GBM Final Real-time Localization
DATE:    23/07/17 02:59:46 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 02:49:08 UT on 17 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230717A (trigger 711254953.822542 / 230717117).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 106.8, Dec = 21.4 (J2000 degrees, equivalent to J2000 07h 07m, 21d 23'), with a statistical uncertainty of 11.3 degrees.

The angle from the Fermi LAT boresight is 64.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230717117/quicklook/glg_skymap_all_bn230717117.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230717117/quicklook/glg_healpix_all_bn230717117.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230717117/quicklook/glg_lc_medres34_bn230717117.gif


GRB_name: GRB230712A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34222
SUBJECT: IPN triangulation of GRB 230712A (short)
DATE:    23/07/17 20:37:09 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
on behalf of the IPN,

A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, report:

The short-duration GRB 230712A
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 34204)
was detected by Fermi (GBM trigger 710815158) and
INTEGRAL (SPI-ACS) at about 81618 s UT (22:40:18).

We have triangulated it to a GBM-SPI-ACS annulus centered at
RA(2000)=216.150 deg (14h 24m 36s) Dec(2000)=+43.693 deg (+43d 41' 34")
whose radius is 74.146 +/- 8.027 deg (3 sigma).

The annulus combined with the Fermi-GBM final position (GCN 34204;
glg_healpix_all_bn230712027_v00) gives 1125 sq. deg (3 sigma) localization region.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB230712_T02353/IPN


GRB_name: GRB230712C
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34223
SUBJECT: IPN triangulation of GRB 230712C (short)
DATE:    23/07/17 20:44:03 GMT
FROM:    Dmitry Svinkin at Ioffe Institute <svinkin@mail.ioffe.ru>

D. Svinkin, D. Frederiks, A. Ridnaia, A. Lysenko,
on behalf of the Konus-Wind team,

A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, report:

The short-duration GRB 230712C
was detected by Fermi (GBM), Konus-Wind, Swift (BAT), and
INTEGRAL (SPI-ACS) at about 2575 s UT (00:42:55).
The burst was detected by Fermi (GBM) during
the trigger record of GRB 230712A (Fermi/GBM trigger 710815158).
The burst occurred during Swift slewing interval
(when normal BAT triggering is disabled).

We have triangulated it to a Konus-SPI-ACS annulus centered at
RA(2000)=110.347 deg (07h 21m 23s) Dec(2000)=+22.378 deg (+22d 22' 41"),
whose radius is 65.487 +/- 17.400 deg (3 sigma).

The annulus combined with the Fermi-GBM position gives 3749 sq. deg (3 sigma) localization region.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB230712_T02575/IPN


GRB_name: GRB230718A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34225
SUBJECT: GRB 230718A: Fermi GBM Final Real-time Localization
DATE:    23/07/18 04:40:41 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely SHORT GRB

At 04:30:02 UT on 18 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230718A (trigger 711347407.352732 / 230718188).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 146.0, Dec = 23.5 (J2000 degrees, equivalent to J2000 09h 43m, 23d 30'), with a statistical uncertainty of 33.5 degrees.

The angle from the Fermi LAT boresight is 79.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230718188/quicklook/glg_skymap_all_bn230718188.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230718188/quicklook/glg_healpix_all_bn230718188.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230718188/quicklook/glg_lc_medres34_bn230718188.gif


GRB_name: GRB230718A
Detection_method: Fermi LAT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34226
SUBJECT: GRB 230718A: Final Localization Correction
DATE:    23/07/18 16:42:46 GMT
FROM:    Oliver J Roberts at USRA/NASA <oliver.roberts@nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

"At 04:30:02.35 UT on 18 July 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230718A (trigger 711347407/230718188).
This trigger was initially classified as a SHORT GRB (GCN 34225) but is in fact a LONG GRB.

The updated on-ground calculated location, using the Fermi GBM trigger data,
is RA = 185.6, Dec = 39.9 degrees, equivalent 12h 22m, +39d 54' (J2000),
with a statistical uncertainty of 15 degrees.

The angle from the Fermi LAT boresight is 43 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230718188/quicklook/glg_skymap_all_bn230718188.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230718188/quicklook/glg_healpix_all_bn230718188.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230718188/quicklook/glg_lc_medres34_bn230718188.gif"


GRB_name: GRB230715D
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34230
SUBJECT: IPN triangulation of GRB 230715D
DATE:    23/07/20 19:12:50 GMT
FROM:    Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,

A. Ridnaia, D. Frederiks, D. Svinkin, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team,

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:

A long-duration GRB 230715D
has been detected by Fermi (GBM trigger 711088412),
Konus-Wind in the waiting mode, Swift (BAT), and 
Mars-Odyssey (HEND), so far, at about 16408 s UT (04:33:28)
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
   38.861 (02h 35m 27s) -65.868 (-65d 52' 05")
 Corners:
   19.987 (01h 19m 57s) -76.691 (-76d 41' 27")
   46.191 (03h 04m 46s) -50.654 (-50d 39' 14")
   44.347 (02h 57m 23s) -48.728 (-48d 43' 41")
   19.602 (01h 18m 24s) -74.655 (-74d 39' 18")
 ---------------------------------------------
The error box area is 34.5 sq. deg, and its maximum
dimension is 24.0 deg (the minimum one is 1.4 deg).
The Sun distance was 94 deg.

The IPN localization is consistent with, but reduces the area of,
the Fermi-GBM final localization (glg_healpix_all_bn230715190_v00).
It was inside the Transiting Exoplanet Survey Satellite (TESS)
field of view (Sector 67, Cameras 3 & 4).

We thank Robert Wilson for pointing out the TESS coverage 
of the IPN localization.

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB230715_T16407/IPN/


GRB_name: GRB230723B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34236
SUBJECT: GRB 230723B: Swift-XRT observations
DATE:    23/07/23 13:08:29 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

S. Campana (INAF-OAB), P.A. Evans (U. Leicester), J.P. Osborne (U.
Leicester), D.N. Burrows (PSU), J.A. Kennea (PSU) and G. Tagliaferri
(INAF-OAB) report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 230723B at 12:37:27.6 UT,
3294.7 seconds after the BAT trigger. No source was detected in 807 s
of promptly downlinked data, which covered 88% of the BAT error circle.
We are waiting for the full dataset to detect and localise the XRT
counterpart.


GRB_name: GRB230723A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34237
SUBJECT: GRB 230723A: AGILE/MCAL detection
DATE:    23/07/23 15:01:44 GMT
FROM:    Gabriele Panebianco <gabriele.panebianco@inaf.it>

G. Panebianco (Univ. Bologna - INAF/OAS Bologna), C. Casentini (INAF/IAPS), F. Verrecchia,
C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
A. Ursi (ASI and INAF/IAPS), A. Argan, M. Cardillo, Y. Evangelista, L. Foffano,
G. Piano (INAF/IAPS), A. Addis, L. Baroncelli, A. Bulgarelli, A. Ciabattoni,
A. Di Piano, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna),
F. Lucarelli (SSDC, and INAF/OAR), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
M. Pilia, A. Trois (INAF/OA-Cagliari), F. Longo (Univ. Trieste and INFN Trieste),
I. Donnarumma, E. Menegoni (ASI), A. Giuliani (INAF/IASF-Mi),  P. Cattaneo (INFN Pavia),
F. Cutrona (Univ. Milano Bicocca) and P. Tempesta (TeleSpazio)
report on behalf of the AGILE Team:

The AGILE satellite detected the GRB 230723A at T0 = 2023-07-23 04:38:43 s (UTC),
reported by Fermi GBM and Global MASTER-Net (GCNs #34232, #34233).

The burst is clearly visible in the AGILE scientific ratemeters of the
MiniCALorimeter (MCAL; 0.4-100 MeV), and AntiCoincidence (AC; 50-200 keV) detectors.
The event lasted about 4 s and it released a total number
of 3239 counts in the MCAL detector (above a background rate of 499 Hz)
and 16051 counts in the AC-Top detector (above a background rate of 2505 Hz).

The AGILE ratemeters light curves can be found at
http://www.agilescienceapp.it/notices/GRB230723A_AGILE_RM_ND.png .

The event also triggered a high time resolution MCAL data acquisition,
from T0-5.0 s to T0+8.6 s (UTC), and released 1186 counts in the detector, above
a background rate of 449 Hz.

The MCAL light curve can be found
at http://www.agilescienceapp.it/notices/GRB230723A_084565_617171923.000000.png .

The time-integrated spectrum of the burst between T0 and T0+2s be fitted in the
energy range 0.4-10 MeV with a power-law with ph. ind. = -1.8 +/- 0.3,
resulting in a reduced chi-squared of 0.94 (48 d.o.f.) and a fluence of 2.5e-06
ergs/cm^2 (90% confidence level), in the same energy range.

At the T0, the event was 103 deg off-axis.

Additional analysis of AGILE data is in progress.
Automatic MCAL GRB alert Notices
can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html


GRB_name: GRB230723B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34238
SUBJECT: Swift-XRT position for GRB 230723B
DATE:    23/07/23 15:59:14 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>

K.L. Page and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT
team:

We have analysed 1.0 ks of XRT data for GRB 230723B, from 3.3 ks to 4.4
ks after the  BAT trigger. The data are entirely in Photon Counting
(PC) mode. The refined XRT position is RA, Dec = 250.3798, -5.3348
which is equivalent to:

RA (J2000): 16 41 31.15
Dec(J2000): -05 20 05.2

with an uncertainty of 4.1 arcsec (radius, 90% confidence).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230723B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34239
SUBJECT: Swift GRB 230723B: Global MASTER-Net observations report
DATE:    23/07/23 17:08:58 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 230723B ( K. L. Page et al., GCN 34234) errorbox  18882 sec after notice time and 18900 sec after trigger time at 2023-07-23 16:57:33 UT, with upper limit up to  19.3 mag. Observations started at twilight.  The observations began at zenith distance = 42 deg. The sun  altitude  is -13.0 deg. 

The galactic latitude b = 25 deg., longitude l = 12 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2243736

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   18990 |         MASTER-SAAO |   C |   180 | 18.1 |        
   18990 |         MASTER-SAAO |   C |   180 | 19.1 |        
   19201 |         MASTER-SAAO |   C |   180 | 18.4 |        
   19201 |         MASTER-SAAO |   C |   180 | 19.3 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230723B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34240
SUBJECT: GRB 230723B: Swift/UVOT Upper Limits
DATE:    23/07/23 21:12:26 GMT
FROM:    Mike Siegel at PSU/Swift MOC <mhs18@psu.edu>

M. H. Siegel (PSU) and K. L. Page (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230723B
3298 s after the BAT trigger (Page et al., GCN Circ. 34234).
No optical afterglow consistent with the XRT position (Page and Evans, 
GCN Circ. 34238)  is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC          3298         3448          147         >20.6
white             3298         4680          344         >20.9
v                 3456         3655          197         >19.1
b                 4276         4475          197         >20.1
u                 4070         4270          197         >20.0
w1                3866         4065          197         >19.3

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.411 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB230723B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34241
SUBJECT: GRB 230723B: Optical limit from CAHA
DATE:    23/07/24 00:11:38 GMT
FROM:    Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>

J.F. Agui Fernandez (IAA-CSIC), A. de Ugarte Postigo (OCA/CNRS), C.C. Thoene (ASU-CAS), M. Blazek (CAHA) report:

We observed the field of GRB 230723B (Page et al. GCN 34234) with CAFOS at the 2.2m CAHA telescope, at Calar Alto Observatory, in Almeria (Spain). The observation consisted of 9x360s exposures in i-band, starting at 20:34 UT and with mean epoch on 0.389 days after the burst. We do not see any new source within the XRT error box (Page & Evans, GCN 34238) down to a 3-sigma limit of 23.0 mag. We do notice that there is a faint object at the Eastern edge of the XRT error box with a magnitude of 22.4 mag, with coordinates (J2000): 16:41:31.43, -5:20:05.7, but that seems to be also there, at a similar magnitude, in the PanSTARRS images. It is not possible at this time to determine if this object could be the host galaxy of GRB 230723B.


GRB_name: GRB230724A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34243
SUBJECT: GRB 230724A: Fermi GBM Final Real-time Localization
DATE:    23/07/24 01:20:54 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely SHORT GRB

At 01:10:29 UT on 24 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230724A (trigger 711853834.451348 / 230724049).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 278.4, Dec = 22.7 (J2000 degrees, equivalent to J2000 18h 33m, 22d 41'), with a statistical uncertainty of 39.4 degrees.

The angle from the Fermi LAT boresight is 135.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230724049/quicklook/glg_skymap_all_bn230724049.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230724049/quicklook/glg_healpix_all_bn230724049.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230724049/quicklook/glg_lc_medres34_bn230724049.gif


GRB_name: GRB230723B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34247
SUBJECT: GRB 230723B: non-detections from Observatoire de Haute-Provence
DATE:    23/07/24 09:43:47 GMT
FROM:    Emeric Le Floc'h at CEA-Saclay <emeric.lefloch@cea.fr>

C. Adami (LAM), J.-C. Cuillandre (CEA Paris-Saclay), M. Ollivier, H. Dole (IAS, UniversitÃ© Paris-Saclay), T. Adami (ENS Paris-Saclay), A. de Ugarte Postigo (OCA/CNRS), E. Le Flocâ€™h, D. GÃ¶tz (CEA Paris-Saclay), A.Saccardi, S.Vergani (GEPI, Obs. de Paris), S. Basa (LAM), report on behalf of a larger collaboration :

We observed the field of GRB 230723B (Page et al. GCN 34234) using the T193cm and T120cm telescopes at Observatoire de Haute-Provence (France). We obtained 26 exposures in the râ€™-band (4x30sec + 22x150sec) with MISTRAL on the T193cm for a total exposure time of 57min, starting at 20:54 UT with a mean epoch at ~0.42days after trigger. At the same time we also obtained 10 exposures of 6min in the I-band at T120cm (total time of 1h). In the râ€™-band and I-band combined frames, we do not detect any new source within the XRT error box (Page & Evans, GCN 34238). Our photometric calibration was performed using nearby stars from the PanSTARRS catalog, leading to the following lower limits :

râ€™ > 21 mag (AB, 3 sigma)
I > 19.25 mag (AB, 3 sigma)

These non-detections are consistent with the CAHA deeper observations in the i-band reported earlier by Agui Fernandez et al. (GCN 34241).

We acknowledge the excellent support from Observatoire de Haute-Provence, in particular Yoann Degot-Longhi, and we also thank Alice Morel.


GRB_name: GRB230723B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34248
SUBJECT: GRB 230723B: Swift-XRT refined Analysis
DATE:    23/07/24 12:37:25 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), V. D'Elia (SSDC
& INAF-OAR), B. Sbarufatti (INAF-OAB), A. D'Ai (INAF-IASFPA), D.N.
Burrows (PSU), J. D. Gropp (PSU), S. Dichiara (PSU), 
 and P.A. Evans report on behalf of the Swift-XRT team:

We have analysed 6.5 ks of XRT data for GRB 230723B, from 3.3 ks to
28.6 ks after the  BAT trigger. The data are entirely in Photon
Counting (PC) mode. Using 1149 s of PC mode data and 3 UVOT images, we
find an enhanced XRT position (using the XRT-UVOT alignment and
matching UVOT field sources to the USNO-B1 catalogue): RA, Dec =
250.37810, -5.33463 which is equivalent to:

RA (J2000): 16h 41m 30.74s
Dec(J2000): -05d 20' 04.7"

with an uncertainty of 2.4 arcsec (radius, 90% confidence).

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.6 (+0.6, -0.4).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.4 (+0.6, -0.5). The
best-fitting absorption column is  6.8 (+4.5, -3.3) x 10^21 cm^-2, in
excess of the Galactic value of 2.2 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.0 x 10^-11 (9.4 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      6.8 (+4.5, -3.3) x 10^21 cm^-2
Galactic foreground: 2.2 x 10^21 cm^-2
Excess significance: 2.3 sigma
Photon index:      2.4 (+0.6, -0.5)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01180410.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230723B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34249
SUBJECT: GRB 230723B: Fermi GBM observation
DATE:    23/07/24 14:00:22 GMT
FROM:    Joe Mangan at IJCLab <joseph.mangan@ijclab.in2p3.fr>

J.Mangan (CNRS/IJCLab) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:

At 11:42:33.03 UT on 23 July 2023, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 230723B (trigger 711805358 / 230723488),
which was also detected by Swift BAT (K. L. Page et al. 2023, GCN 34234).
The Fermi GBM on-ground location is consistent with the Swift BAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 78 degrees.

The GBM light curve consists of a single peak
with a duration (T90) of about 10 s (50-300 keV).
The time-averaged spectrum from T0-2 s to T0+9 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.9 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 59.1 +/- 2.7 keV.

The event fluence (10-1000 keV) in this time interval is
(3.8 +/- 0.2)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.2 s in the 10-1000 keV band
is 7.8 +/- 0.4 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/


GRB_name: GRB230723B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34250
SUBJECT: GRB 230723B: Bassano Bresciano Observatory upper limit
DATE:    23/07/24 15:54:42 GMT
FROM:    Ulisse Quadri at Bassano Bresciano Obs <oabb@ulisse.bs.it>

U.Quadri and  L.Strabla (Bassano Bresciano Astronomical Observatory),
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report: 

We imaged the field of GRB 230723B detected by SWIFT(trigger 1180410)
with the robotic telescope of (IAU station 565) Bassano Bresciano 
Observatory, Italy. Member of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
GAC - Gruppo Astrofili Cremonesi.

The observations started 518 min after the GRB trigger, at the end of twilight, 
with our Newton telescope D=250 mm F/D=4.8.

Weather conditions were medium.

We co-added 70 exposures of 120 sec each.

Start T0+      End T0+       R lim
518.43 min   598.40 min      19

We did not found any optical counterpart in the error box of the XRTcandidate.
Page et al. GCN 34234

Magnitudes were estimated with the Gaia DR2 cat. and 
are not corrected for galactic dust extinction.

Reference:
http://www.osservatoriobassano.org/GRB.asp

The message may be cited.


GRB_name: GRB230723B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34251
SUBJECT: GRB 230723B: Optical afterglow candidate from CAHA
DATE:    23/07/24 17:05:45 GMT
FROM:    Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>

J.F. Agui Fernandez (IAA-CSIC), A. de Ugarte Postigo (OCA/CNRS), C.C. Thoene (ASU-CAS), M. Blazek and Ana Guijarro Roman (CAHA) report:

After XRT delivered its refined analysis and updated GRB localisation (Osborne et al. GCN 34248) we noticed that the new localisation has very little overlap with the fist one. The revised localisation is no longer consistent with the object mentioned in our previous GCN (Agui Fernandez et al. GCN 34241). However, within the new localisation circle and outside the original one, we detect an object at coordinates (J2000): 16:41:30.65 -5:20:04.5 with an AB magnitude of i =  22.4+/-0.2 mag as compared to PanSTARRS field objects. No object is detected in PanSTARRS at this position. Further observations will be needed to confirm the object variability and its possible identification as the optical counterpart of GRB 230723A.


GRB_name: GRB230723B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34252
SUBJECT: GRB 230723B: Montarrenti Observatory upper limit
DATE:    23/07/24 18:30:42 GMT
FROM:    Simone Leonini at Montarrenti Observatory (Siena, Italy) <s.leonini@iol.it>

S. Leonini, M. Conti, P. Rosi, L.M. Tinjaca Ramirez and L. Bellizzi (Montarrenti Observatory, Siena, Italy) report:

We observed the field of the GRB 230723B (Trigger 1180410, K.L. Page et al., GCN 34234, V. Lipunov, GCN 34239; J.F. Agui Fernandez, GCN 34241; C. Adami, GCN 34247; U. Quadri, GCN 34250; J.F. Agui Fernandez, GCN 34251) with the automatic 0.53m Ritchey-Chretien telescope + U47 detector at Montarrenti Observatory (Siena, Italy, IAU code C88).

The observations were started under good weather conditions at 2023-07-23 21:13:37 UT (approximately 9.5 hours after notice) stacking 30x30s clear filter CCD exposures.

We have not found optical transient within the error-box of the Neil Gehrels Swift Observatory position (RA 16h 41m 30.74s, Dec. -05d 20m 04.7s - J2000).  
Mag. upper limit R = 20.83 +/-0.14

Magnitudes were obtained from USNO-B1 catalogue and are not corrected for galactic extinction.


GRB_name: GRB230723B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34253
SUBJECT:  GRB 230723B: Osservatorio Astronomico Nastro Verde upper limit
DATE:    23/07/24 20:20:44 GMT
FROM:    Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 <osservatorionastroverde@gmail.com>

Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report: 

We image the field of GRB 230723B detected by SWIFT(trigger 1180410)
with telescope of Nastro Verde Observatory - Sorrento (Naples), Italy. Member of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
AstroCampania Associazione

The observations started at 19:19 UT of  2023/07/23, after 7,40 hours after the GRB trigger, at the end of twilight
with principal telescope  SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME
I took 32 image of 60 sec each. All images are unfiltered, calibrated with masterdark and masterflat,stacked with Tycho Tracker software
We have not detected any clearly visible sources, up to 20th magnitude with clear skies.
   Start T0+                  End T0+        Rlim
19:19:39 UT            19:54:47 UT      20

We did not found any optical counterpart in the error box of the XRTcandidate.
Page et al. GCN 34234



Magnitudes were estimated with the Gaia DR2 cat. and 
are not corrected for galactic dust extinction.



The message may be cited.


GRB_name: GRB230723B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34254
SUBJECT: GRB 230723B: Leavitt Observatory upper limit
DATE:    23/07/24 20:32:05 GMT
FROM:    leavittob@gmail.com

E. Pavoni and L. Moretti (Leavitt Observatory), in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report: 

We imaged the field of GRB 230723B detected by SWIFT(trigger 1180410)
with telescope of Leavitt Observatory, Italy. Member of: 
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
ATA - Associazione Tuscolana di Astronomia.

The observations began at 21:31 UT on 2023/07/23, 577 min after the GRB trigger, with our RC telescope D=250 mm F/D=8.

Weather conditions were medium.

We took 30 images of 120 sec each. All images are unfiltered, calibrated with master dark and master flat, stacked with ASTAP software.

We have not detected any clearly visible sources, up to 19.9th magnitude with clear sky at 
RA(J2000)  = 16h 41m 43.83s
Dec(J2000) = -05d 17' 16.04"

on a field of view 31.1 x 26.8 arcmin

Start                End              Rlim
577 min         637 min      19.9

Magnitudes were estimated with the Gaia DR3 cat. and are not corrected for galactic dust extinction.

The message may be cited.


GRB_name: GRB230725A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34255
SUBJECT: GRB 230725A: Fermi GBM Final Real-time Localization
DATE:    23/07/25 10:43:21 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely SHORT GRB

At 10:32:50 UT on 25 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230725A (trigger 711973975.87891 / 230725439).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 207.2, Dec = 4.9 (J2000 degrees, equivalent to J2000 13h 48m, 4d 54'), with a statistical uncertainty of 4.5 degrees.

The angle from the Fermi LAT boresight is 31.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230725439/quicklook/glg_skymap_all_bn230725439.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230725439/quicklook/glg_healpix_all_bn230725439.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230725439/quicklook/glg_lc_medres34_bn230725439.gif


GRB_name: GRB230725B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34256
SUBJECT: GRB 230725B: Fermi GBM Final Real-time Localization
DATE:    23/07/25 13:08:51 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 12:58:19 UT on 25 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230725B (trigger 711982704.317538 / 230725540).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 30.2, Dec = 47.8 (J2000 degrees, equivalent to J2000 02h 00m, 47d 47'), with a statistical uncertainty of 1.0 degrees.

The angle from the Fermi LAT boresight is 2.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230725540/quicklook/glg_skymap_all_bn230725540.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230725540/quicklook/glg_healpix_all_bn230725540.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230725540/quicklook/glg_lc_medres34_bn230725540.gif


GRB_name: GRB230723A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34258
SUBJECT: IPN triangulation of GRB 230723A (short)
DATE:    23/07/25 15:40:41 GMT
FROM:    Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,

A. Ridnaia, D. Frederiks, D. Svinkin, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:

The short-duration GRB 230723A
(Fermi GBM detection: The Fermi GBM team, GCN 34232;
AGILE/MCAL detection: Panebianco et al., GCN 34237)
has been detected by Fermi (GBM), Konus-Wind, 
AGILE (MCAL, AC), and Mars-Odyssey (HEND), so far, 
at about 16723 s UT (04:38:43).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
   22.909 (01h 31m 38s) -67.059 (-67d 03' 31")
 Corners:
   24.618 (01h 38m 28s) -66.230 (-66d 13' 48")
   24.638 (01h 38m 33s) -66.276 (-66d 16' 34")
   21.066 (01h 24m 16s) -67.859 (-67d 51' 31")
   21.054 (01h 24m 13s) -67.813 (-67d 48' 46")
 ---------------------------------------------
The error box area is 265 sq. arcmin, and its maximum
dimension is 2.1 deg (the minimum one is 2 arcmin).
The Sun distance was 111 deg.

The IPN localization is consistent with, but reduces 
the area of, the Fermi-GBM final localization (GCN 34232).

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB230723_T16725/IPN/

The Konus-Wind time history and spectrum will be given
in a forthcoming GCN Circular.


GRB_name: GRB230723B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34259
SUBJECT: GRB 230723B: GAD Observatory, La Spezia, Italy upper limit
DATE:    23/07/25 21:01:33 GMT
FROM:    Claudio Lopresti <cl3lop@gmail.com>

Claudio Lopresti (Gruppo Astronomia Digitale - GAD Observatory, La Spezia, Italy)
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
Unione Astrofili Italiani (UAI)
report: 
 
We imaged the field of GRB 230723B detected by SWIFT(trigger 1180410)
with the telescope LX200 12â€ of GAD Observatory, La Spezia, Italy
Member of: 
 
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili, GRB section.
GAD - Gruppo Astronomia Digitale.
 
The observations started 557 min after the GRB trigger, at the end of twilight, 
with a Shmidt-Cassegrain telescope D=304 mm with reducer F/D=4.75.
 
Weather conditions were medium.
 
We co-added 42 exposures of 120 sec each.
 
 
Start T0+      End T0+       R lim
557 min        641 min         19
 
We did not found any optical counterpart in the error box of the XRT candidate.
Page et al. GCN 34234
 
Magnitudes were estimated with the Gaia EDR3 cat. and 
are not corrected for galactic dust extinction.
 
Reference:
https://www.parcodellestelle.com/
 
The message may be cited.


GRB_name: GRB230723B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34267
SUBJECT: GRB 230723B: ATCA rapid radio follow-up
DATE:    23/07/26 05:29:00 GMT
FROM:    Gemma Anderson at Curtin U <gemma.anderson@curtin.edu.au>

G. E. Anderson (Curtin), A. Gulati (USyd), J. K. Leung (USyd), A. J. van der Horst (GWU), L. Rhodes (Oxford), S. Chastain (UNM) on behalf of the PanRadio GRB collaboration

The Australia Telescope Compact Array (ATCA) performed rapid-response follow-up observations of the long GRB 230723B (Page et al. GCN 34234) at 5.5, 9, 16.7, and 21.2 GHz as part of the Large ATCA â€œPanRadio GRBâ€ follow-up programme C3542 (PI. Anderson). ATCA was on target observing at  2023-07-23 11:51 UT,  just 9 minutes post-burst and observed for 4 hrs. There is no radio source coincident with the enhanced XRT position (Page et al. GCN 34238) with 3 sigma upper limits of 150, 90, 90 and 150 microJy/beam at 5.5, 9.0, 16.7 and 21.2 GHz, respectively. Further observations are planned.

We thank the CSIRO Space and Astronomy staff for supporting these observations and maintaining the ATCA rapid-response observing mode.

We acknowledge the Gomeroi people as the traditional owners of the Observatory site. The Australia Telescope Compact Array is part of the Australia Telescope National Facility (https://ror.org/05qajvd42) which is funded by the Australian Government for operation as a National Facility managed by CSIRO.


GRB_name: GRB230723B
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34268
SUBJECT: GRB 230723B: MITSuME Akeno optical afterglow candidate detection
DATE:    23/07/26 13:34:48 GMT
FROM:    Mahito Sasada at Tokyo Institute of Technology <sasada@hp.phys.titech.ac.jp>

M. Sasada, I. Takahashi, M. Niwano, S. Sato, S. Hayatsu, N. Higuchi, H. Takei, H. Seki, Y. Yatsu (Tokyo Tech), K. L. Murata (Kyoto U) and N. Kawai (Riken) report on behalf of the MITSuME collaboration:

We observed the field of GRB 230723B (Page et al. GCN Circular #34234, Campana et al. #34236, Page et al. #34238, Lipunov et al. #34239, Siegle et al. #34240, Agui Fernandez et al. #34241, Adami et al. #34247, Osborne et al. #34248, Mangan et al. #34249, Quadri et al. #34250, Agui Fernandez et al. #34251, Leonini et al. #34252, Ruocco et al. #34253, Pavoni et al. #34254, Lopresti et al. #34259, Anderson et al. #34267) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno.

The observation with a series of 10 sec exposures started at 2023-07-23 11:43:20 UT (48 seconds after the Swift/BAT detection). We stacked the images with good conditions. In the stacked image at 454 seconds after the burst, we detected an object of Ic=17.1+/-0.2 at the coordinate reported by Agui Fernandez et al. #34251. We also report the gâ€™-, Rc- and Ic-band 3-sigma upper limits of the stacked images.

T0+[sec] |MID-UT | T-EXP[sec] | 3-sigma limits
------------------------------------------------------------------------------------------------
454  | 2023-07-23 11:50:06 | 220 | gâ€™>18.0, Rc>17.8, Ic>17.6
1419 | 2023-07-23 12:06:11 | 1020 | gâ€™>18.6, Rc>18.5, Ic>18.2
 3763 | 2023-07-23 12:45:15 | 1890 | g'>19.0, Rc>18.5, Ic>18.0
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time

We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1 r and i bands were converted to our Rc- and Ic-band magnitudes following Tonry et al. (2012), Table 6. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).


GRB_name: GRB230723A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34269
SUBJECT: Konus-Wind detection of GRB 230723A
DATE:    23/07/26 15:06:31 GMT
FROM:    Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>

A.Ridnaia, D. Frederiks, A.Lysenko, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The short-duration GRB 230723A
(Fermi GBM detection: The Fermi GBM team, GCN 34232;
AGILE/MCAL detection: Panebianco et al., GCN 34237;
IPN triangulation: Kozyrev et al., GCN 34258)
triggered Konus-Wind at T0=16725.802 s UT (04:38:45.802).

The burst light curve shows a multipeaked structure,
which starts at T0-0.346 s and has a total duration of ~0.62 s.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB230723_T16725/

As observed by Konus-Wind, the burst
had a fluence of 1.66(-0.06,+0.54)x10^-6 erg/cm2,
and a 16-ms peak flux, measured from T0-0.220 s,
of 8.56(-1.76,+3.29)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

Since the main fraction of the burst emission was detected
before the trigger, the spectral analysis was performed using
the KW 3-channel light curve data.

Modelling the KW 3-channel time-integrated spectrum
(measured from T0-0.346 s to T0+0.620 s)
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep),
yields alpha = -0.21(-0.26,+0.27) and Ep = 659(-99,+162) keV.

All the quoted errors are at the 68% confidence level.
All the quoted values are preliminary.


GRB_name: GRB230723B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34271
SUBJECT: GRB 230723B: Further CAHA observations and host galaxy detection
DATE:    23/07/26 17:36:30 GMT
FROM:    Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>

J.F. Agui Fernandez (IAA-CSIC), A. de Ugarte Postigo (OCA/CNRS), C.C. Thoene (ASU-CAS), J. Flores and Ana Guijarro Roman (CAHA) report:

We have performed follow-up observations on the GRB 230723B field (Page et al. GCN 34324, Osborne et al. GCN 34248) with CAFOS in the 2.2m telescope at the Calar Alto Observatory in Almeria, Spain. Observations consisted of 9x360s in i-band, starting at 2023-07-25T20:46:11 UT with a mean epoch 2.393 days after the burst. We detect the object reported in Agui Fernandez et al. (GCN 34251) at a magnitude consistent with our previous observation. 
The early optical detection of the transient at a consistent location by Sasada et al. (GCN 34268) indicates that the detection in the first Calar Alto observation was already dominated by the host galaxy contribution. The interpolation from the observation of Sasada et al. (GCN 34251) to the one of Agui Fernandez et al. (GCN 34251) indicates a decay rate of at least alpha=1.1 (where F_nu ~ t^-alpha). Extrapolating this, the GRB afterglow should be dimmer than 24 mag at the time of our follow-up observations. We do note, that the host galaxy should be in the range for emission line spectroscopy with 8-10m telescopes.


GRB_name: GRB230727A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34275
SUBJECT: GRB 230727A: Fermi GBM Final Real-time Localization
DATE:    23/07/27 11:13:44 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 11:03:06 UT on 27 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230727A (trigger 712148591.84604 / 230727460).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 323.8, Dec = 73.7 (J2000 degrees, equivalent to J2000 21h 35m, 73d 42'), with a statistical uncertainty of 1.2 degrees.

The angle from the Fermi LAT boresight is 100.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230727460/quicklook/glg_skymap_all_bn230727460.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230727460/quicklook/glg_healpix_all_bn230727460.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230727460/quicklook/glg_lc_medres34_bn230727460.gif


GRB_name: GRB230727A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34280
SUBJECT: GRB 230727A: Swift/BAT-GUANO detection of a burst
DATE:    23/07/28 01:05:25 GMT
FROM:    Jimmy DeLaunay at University of Alabama  <delauj2@gmail.com>

James DeLaunay (UAlabama), Gayathri Raman (PSU), Samuele Ronchini (PSU), Aaron Tohuvavohu (U Toronto), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report:

Swift/BAT did not localize GRB 230727A onboard (T0: 2023-07-27T11:03:06.85 UTC, Fermi Trig 712148591, GCN 34275). 

The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), detects the burst with a sqrt(TS) of 11 in a 2.048 s analysis time bin.

NITRATES results, independently, are ambiguous with respect to whether this burst originates from in or outside the BAT coded FOV, with a borderline DeltaLLHOut of 7.4.
The Fermi GBM localization (GCN 34275) has this burst significantly outside of the BAT coded FOV

See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/


GRB_name: GRB230728A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34282
SUBJECT: GRB 230728A: Swift detection of a burst
DATE:    23/07/28 03:07:03 GMT
FROM:    David Palmer at LANL <palmer@lanl.gov>


C. Salvaggio (INAF-OAB), P. D'Avanzo (INAF-OAB), S. Laha (GSFC/UMBC),
D. M. Palmer (LANL), T. M. Parsotan (GSFC/UMBC/CRESSTII) and
M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 02:50:03 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 230728A (trigger=1181187).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 343.539, +28.151 which is 
   RA(J2000) = 22h 54m 09s
   Dec(J2000) = +28d 09' 03"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  Due to a telemetry gap, BAT lightcurve information
is not immediately available. 

The XRT began observing the field at 02:51:33.5 UT, 90.3 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source with an enhanced position: RA, Dec 343.51530,
28.17470 which is equivalent to:
   RA(J2000)  = 22h 54m 03.67s
   Dec(J2000) = +28d 10' 28.9"
with an uncertainty of 1.9 arcseconds (radius, 90% containment). This
location is 113 arcseconds from the BAT onboard position, within the
BAT error circle. This position may be improved as more data are
received; the latest position is available at
https://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (6.29 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 7.2
(+2.52/-2.21) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 7.13e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 99 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.079. 

Burst Advocate for this burst is C. Salvaggio (chiara.salvaggio AT inaf.it). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB230727A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34283
SUBJECT: GRB 230727A: AstroSat CZTI detection
DATE:    23/07/28 06:47:03 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>

B. Pari (IITB), P K. Navaneeth (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long GRB 230727A which was also detected by Fermi (Fermi GBM Team, GCN Circ. 34275) and Swift/BAT-GUANO (DeLaunay et al., GCN Circ. 34280).

The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2023-07-27 11:03:09.45 UTC. The measured peak count rate associated with the burst is 709.2 (+211.2, -56.0) counts/s above the background in the combined data of all quadrants, with a total of 1916 (+278, -290) counts. The local mean background count rate was 522.1 (+5.0, -7.7) counts/s. Using cumulative rates, we measure a T90 of 11.8 (+2.5, -1.6) s.

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2023-07-27 11:03:08.85 UTC. The measured peak count rate associated with the burst is 343.3 (+76.9, -79.7) counts/s above the background in the combined data of all quadrants, with a total of 1231 (+419, -444) counts. The local mean background count rate was 1992.2 (+5.8, -7.1) counts/s. We measure a T90 of 11.3 (+3.7, -5.1) s from the cumulative Veto light curve.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB230728A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34285
SUBJECT: GRB 230728A: NOT optical observations and possible host galaxy
DATE:    23/07/28 09:23:06 GMT
FROM:    Dong Xu at NAOC/CAS <dxu@nao.cas.cn>

D. Xu, S.Y. Fu, S.Q. Jiang, Z.P. Zhu (NAOC), Z. Gray (NOT), report:

We observed the field of GRB 230728A detected by Swift (Salvaggio et al., GCN 34282) using the the 2.56-m Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations started at 04:26:55 UT on 2023-07-28, i.e., ~ 1.61 hr after the Swift/BAT trigger, and 3x300 s Sloan r-filter images and 5x200 s Sloan z-filter images were obtained, respectively.

No optical source is detected within or at the border of the Swift/XRT error circle (radius ~1.9 arcsec, 90% containment, Salvaggio et al., GCN 34282) down to upper limits of r > 24.2 mag (5-sigma) and z > 23.0 mag (5-sigma).

We note that there exists a galaxy south-western, ~3.7 arcsec away from the center of the Swift/XRT error circle. This galaxy is present in SDSS with r ~ 22.39 mag, z ~ 22.99 mag, z_phot ~ 0.34, and in Legacy Survey with r ~ 22.14 mag, z ~ 22.04 mag, z_phot ~ 0.37, respectively. Preliminary photometry of the galaxy from the NOT data gives r ~ 22.4 mag and z ~ 23.0 mag, which are consistent with the above archival values, indicating that there is no prominent optical afterglow in this potential host galaxy.


GRB_name: GRB230728A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34286
SUBJECT: GRB 230728A: Enhanced Swift-XRT position
DATE:    23/07/28 11:08:36 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1173 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 230728A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 343.51572, +28.17433 which is equivalent
to:

RA (J2000): 22h 54m 3.77s
Dec (J2000): +28d 10' 27.6"

with an uncertainty of 2.1 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB230728A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34287
SUBJECT: GRB 230728A: Swift-XRT refined Analysis
DATE:    23/07/28 12:26:15 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), B. Sbarufatti
(INAF-OAB), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAR), J. D. Gropp
(PSU), S. Dichiara (PSU), J.A. Kennea (PSU), A.P. Beardmore (U.
Leicester) and P.A. Evans report on behalf of the Swift-XRT team:

We have analysed 6.7 ks of XRT data for GRB 230728A, from 86 s to 28.9
ks after the  BAT trigger. The data comprise 94 s in Windowed Timing
(WT) mode (the first 3 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. 

The late-time light curve (from T0+5.6 ks) can be modelled with a
power-law decay with a decay index of alpha=1.19 (+0.20, -0.22).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.97 (+0.24, -0.23). The
best-fitting absorption column is  4.4 (+1.4, -1.2) x 10^21 cm^-2, in
excess of the Galactic value of 6.3 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.04 (+0.19, -0.18)
and a best-fitting absorption column of 7.0 (+1.5, -1.3) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.3 x 10^-11 (7.6 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      7.0 (+1.5, -1.3) x 10^21 cm^-2
Galactic foreground: 6.3 x 10^20 cm^-2
Excess significance: 8.1 sigma
Photon index:      2.04 (+0.19, -0.18)

If the light curve continues to decay with a power-law decay index of
1.19, the count rate at T+24 hours will be 6.2 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.6 x
10^-13 (4.7 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01181187.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230728A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34288
SUBJECT: GRB 230728A: Swift/UVOT Upper Limits
DATE:    23/07/28 14:37:00 GMT
FROM:    Samantha Oates at University of Birmingham <samantha.oates@alumni.ucl.ac.uk>

S. R. Oates (U. Birmingham) and C. Salvaggio (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230728A
100 s after the BAT trigger (Salvaggio et al., GCN Circ. 34282).
No optical afterglow consistent with the XRT position (Evans et al.,
GCN Circ. 34286) is detected in the initial UVOT exposures.

Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           100          250          147         >20.9
u_FC               312          562          246         >20.1
white              100         1361          372         >21.1
v                  641         5845          274         >19.4
b                  567         1338           78         >19.5
u                  312         1313          304         >20.0
w1                 691         1289           58         >18.5
m2                5851         6048          194         >19.5
w2                1023         1380           52         >18.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.080 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB230728A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34289
SUBJECT: GRB 230728A: LCOGT Optical Upper Limit
DATE:    23/07/28 14:44:26 GMT
FROM:    Robert Strausbaugh at University of Minnesota <rstrausb@umn.edu>

R. Strausbaugh (University of Minnesota), A. Cucchiara (NASA) report on
behalf of a larger collaboration:

We observed the GRB 230728A (Salvaggio et al., GCN 34282) field with the
LCOGT 1-meter Sinistro instrument at the Teide Observatory, Tenerife site,
on July 28, from 03:15 to 03:48 UT (corresponding to 0.42 to 0.97 hours
from the GRB trigger time) with the SDSS r and i filters.

We performed a series of 3x300s exposures in each band.  We do not detect
any source within the enhanced Swift-XRT error region (Evans et al., GCN
34286) in either band, consistent with later optical upper limits (Xu et
al., GCN 34285).

The following upper limits are calculated using the PanSTARRS catalog as
reference:

r > 23.3
i > 22.8

These magnitudes are not corrected for galactic extinction.


GRB_name: GRB230728A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34290
SUBJECT: GRB 230728A: Fermi GBM Observation
DATE:    23/07/28 18:51:37 GMT
FROM:    Sarah Dalessi at UAH <sd0104@uah.edu>

S. Dalessi (UAH) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 02:50:05.24 UT on 28 July 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230728A (trigger 712205410/230728118).
which was also detected by Swift BAT (Salvaggio et al. 2023, GCN 34282) and Swift XRT (Evans et al. 2023, GCN 34286).
The Fermi GBM on-ground location is consistent with the Swift XRT position.

The angle from the Fermi LAT boresight is 66 degrees.

The GBM light curve consists of multiple peaks with a duration (T90)
of about 19 s (50-300 keV). The time-averaged spectrum
from T0-6.1 to T0+12.3 s is best fit by
a power law function with an exponential high-energy cutoff.
The power law index is -1.2 +/- 0.2 and the cutoff energy,
parameterized as Epeak, is 95 +/- 15 keV.

The event fluence (10-1000 keV) in this time interval is
(1.7 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-2.6 s in the 10-1000 keV band is 3.1 +/- 0.2 ph/s/cm^2.

A Band function fits the spectrum equally well
with Epeak= 78 +/- 20 keV, alpha = -1.1 +/- 0.3 and beta = -2.4 +/- 0.4.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB230728A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34291
SUBJECT: GRB 230728A: BOOTES-1 optical upper limit
DATE:    23/07/28 19:11:16 GMT
FROM:    Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado, M.D. Caballero-Garcia, R. Sanchez-Ramirez, I. Perez-Garcia and S. Guziy  (IAA-CSIC), C. Perez del Pulgar, A. Castellon, I. Carrasco and A. Reina (Univ. de Malaga) and F. Rendon (IAA-CSIC and INTA-CEDEA) on behalf of a larger collaboration, report:

Following the detection of GRB 230728A by Swift (Salvaggio et al., GCNC 34282), the 0.3m BOOTES-1B robotic telescope in Mazagon (Huelva, Spain) automatically responded to this burst on Jul. 28 at 02:50:54 UT (i.e. ~51 s after trigger). In the co-added frame (60 x 10 s, clear filter), no source is detected within the enhanced XRT position (Evans et al., GCNC 34286) down to 19.9 mag.

This non-detection is consistent with the upper limits reported by MASTER (Lipunov et al. GCNC 34281), NOT (Xu et al. GCNC 34285), UVOT (Oates et al. GCNC 34288) and LCOGT (Strausbaugh et al. GCNC 34289).

We thank the staff at INTA-CEDEA for their excellent support.


GRB_name: GRB230723B
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34295
SUBJECT: GRB 230723B: MITSuME Ishigaki optical observation
DATE:    23/07/30 08:54:50 GMT
FROM:    Natsuki Hayatsu H. at Ishigakijima Astronomical Observatory <natsuki.h.hayatsu@gmail.com>

N. H. Hayatsu, H. Hanayama (NAOJ), M. Sasada, I. Takahashi, M. Niwano, S. Sato, S. Hayatsu, N. Higuchi, H. Takei, H. Seki, Y. Yatsu (Tokyo Tech), K. L. Murata (Kyoto U) and N. Kawai (Riken) report on behalf of the MITSuME collaboration:

report:

We observed the field of GRB 230723B (Page et al. GCN Circular #34234, Campana et al. #34236, Page et al. #34238, Lipunov et al. #34239, Siegle et al. #34240, Agui Fernandez et al. #34241, Adami et al. #34247, Osborne et al. #34248, Mangan et al. #34249, Quadri et al. #34250, Agui Fernandez et al. #34251, Leonini et al. #34252, Ruocco et al. #34253, Pavoni et al. #34254, Lopresti et al. #34259, Anderson et al. #34267, Sanada et al. #34268, and Agui Fernandez et al. #34271) with the optical three color (g', Rc, and Ic) CCD cameras attached to the 105 cm Murikabushi telescope of Ishigakijima Astronomical Observatory, Okinawa, Japan. 

The observation with a series of 60 sec exposures started at 2023-07-23 12:21:20.29 UT (2328 seconds after the Swift/BAT detection). In the stacked image at 3193 seconds after the burst, we detected an object of g'=20.5+/-0.2, Rc=19.4+/-0.1, and Ic=19.6+/-0.1 at the coordinate reported by Agui Fernandez et al. #34251. We also report the gâ€™-, Rc- and Ic-band 5-sigma upper limits of the stacked images.

TT0+[sec] | MID-UT | T-EXP[sec] | candidate magnitudes | 5-sigma limits
------------------------------------------------------------------------------------------------
3193 | 2023-07-23 12:35:45 | 1080 | g'=20.5+/-0.2, Rc=19.4+/-0.1, Ic=19.6+/-0.1 | g'>20.6, Rc>21.2, Ic>20.1
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time

We used PS1 catalog for flux calibration. The conversion from PS1 r and i band to our Rc and Ic band is by the equation of Tonry et al. (2012), Table. 6. The magnitudes are expressed in the AB system. The images were processed through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).


GRB_name: GRB230723B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34297
SUBJECT: GRB 230723B: Swift-BAT refined analysis
DATE:    23/07/30 13:50:12 GMT
FROM:    Tyler Parsotan  at NASA GSFC <tyler.parsotan@nasa.gov>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC), 
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),
D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):
 
Using the data set from T-240 to T+60 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230723B (trigger #1180410)
(Page, et al., GCN Circ. 34234).  The BAT ground-calculated position is
RA, Dec = 250.391, -5.319 deg which is 
   RA(J2000)  =  16h 41m 33.8s 
   Dec(J2000) = -05d 19' 08.1" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 39%.
 
The light curve shows a fast rise exponential decay type profile.
T90 (15-350 keV) is 6.64 +- 0.81 sec (estimated error including systematics).
 
The time-averaged spectrum from T-0.22 to T+7.94 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.09 +- 0.38, 
and Epeak of 65.9 +- 15.8 keV (chi squared 41.57 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.7 +- 0.1 x 10^-06 erg/cm2
and the 1-sec peak flux measured from T+1.64 sec in the 15-150 keV band is
5.1 +- 0.5 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.77 +- 0.08 (chi squared 52.21 for 57 d.o.f.).  All the quoted errors
are at the 90% confidence level. 
 
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1180410/BA/


GRB_name: GRB230728A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34299
SUBJECT: GRB 230728A: Swift-BAT refined analysis
DATE:    23/07/31 12:57:17 GMT
FROM:    Tyler Parsotan  at NASA GSFC <tyler.parsotan@nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC),

H. A. Krimm (NSF), S. Laha (GSFC/UMBC),

A. Y. Lien (U Tampa), C. B. Markwardt (GSFC),

D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC),

T. Sakamoto (AGU), (i.e. the Swift-BAT team):



Using the data set from T-240 to T+962 sec from the recent telemetry downlink,

we report further analysis of BAT GRB 230728A (trigger #1181187)

(Salvaggio, et al., GCN Circ. 34282).  The BAT ground-calculated position is

RA, Dec = 343.514, 28.169 deg which is

   RA(J2000)  =  22h 54m 03.4s

   Dec(J2000) = +28d 10' 09.5"

with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).

The partial coding was 49%.



He mask-weighted light curve shows a complex multi-peaked structure with some

emission prior to the trigger time.

T90 (15-350 keV) is 15.10 +- 0.89 sec (estimated error including systematics).



The time-averaged spectrum from T-5.62 to T+10.74 sec is best fit by a simple

power-law model.  The power law index of the time-averaged spectrum is

1.58 +- 0.13.  The fluence in the 15-150 keV band is 1.1 +- 0.1 x 10^-06 erg/cm2.

The 1-sec peak photon flux measured from T+0.41 sec in the 15-150 keV band

is 2.5 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence

level.



The results of the batgrbproduct analysis are available at

http://gcn.gsfc.nasa.gov/notices_s/1181187/BA/


GRB_name: GRB230723A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34301
SUBJECT: GRB 230723A: Detection of candidate millimeter-band radiation by SPT-3G
DATE:    23/07/31 19:40:10 GMT
FROM:    Sam Guns at S Pole Telescope & UC Berkeley <sguns@berkeley.edu>

S. Guns (UC Berkeley), A. Foster (CWRU), C. Tandoi (UIUC), K. Phadke (UIUC), N. Whitehorn (MSU), G. Holder (UIUC), J. Vieira (UIUC) on behalf of the South Pole Telescope Collaboration: 

On 26 July 2023 at 16:48 UTC the South Pole Telescope detected a millimeter-band transient candidate at RA = 43.5275, Dec = -70.4770 (J2000 degrees, uncertainty 12 arcseconds) using the SPT-3G camera in 2 bands centered at 95 GHz and 150 GHz. Peak emission was observed two hours later at 19:14 UTC with flux levels of 18.5 mJy in both bands, after which the SPT slewed away from the observing field. The next series of observations on 28 July showed flux levels consistent with zero. The spatial location of the emission is consistent (1.5 sigma) with GRB 230723A which was detected by Fermi-GBM on 23 July 2023 at RA = 21.0, Dec = -71.2 (J2000 degrees, uncertainty 4.8 degrees). From the SPT-3G transients program, short duration (<1 week) millimeter-band transients that are not associated with nearby stars are rare (<3 events per year). A table of SPT-3G observations is given below. 

The lightcurve can be found at:
https://pole.uchicago.edu/public/data/transients/lightcurves/SPT-SVJ025406.5-702837.png

Observation time  | Flux (95 GHz) | Error (95 GHz) | Flux (150 GHz) | Error (150 GHz)
2023-7-22 05:04 UTC | -3.0 mJy | 2.5 mJy | -3.3 mJy | 3.0 mJy 
2023-7-26 16:48 UTC | 13.3 mJy | 4.4 mJy | 14.0 mJy | 4.9 mJy
2023-7-26 19:14 UTC | 18.5 mJy | 4.4 mJy | 18.5 mJy | 4.9 mJy
2023-7-28 08:12 UTC | 1.7 mJy | 2.5 mJy | 1.8 mJy | 2.8 mJy 

The South Pole Telescope is a 10-meter telescope located at Amundsen-Scott South Pole Station and supported by the National Science Foundation and the US Dept. of Energy. The SPT online transient program providing data in this circular is supported by NSF grants AST-1716965 and OPP 1852617, and observes 1500 square degrees of the southern sky at 95, 150, and 220 GHz with an average revisit cadence of 12 hours. For more details on the SPT transient program and survey strategy, please see https://arxiv.org/abs/2103.06166.


GRB_name: GRB230731A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34305
SUBJECT: GRB 230731A: Fermi GBM Final Real-time Localization
DATE:    23/07/31 23:49:46 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 23:39:16 UT on 31 Jul 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230731A (trigger 712539561.432998 / 230731986).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 237.3, Dec = -58.9 (J2000 degrees, equivalent to J2000 15h 49m, -58d 53'), with a statistical uncertainty of 8.3 degrees.

The angle from the Fermi LAT boresight is 111.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230731986/quicklook/glg_skymap_all_bn230731986.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230731986/quicklook/glg_healpix_all_bn230731986.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230731986/quicklook/glg_lc_medres34_bn230731986.gif


GRB_name: GRB230723A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34309
SUBJECT: GRB 230723A: SPT-3G millimeter-band transient event inconsistent with IPN position
DATE:    23/08/01 20:16:17 GMT
FROM:    Sam Guns at S Pole Telescope & UC Berkeley <sguns@berkeley.edu>

S. Guns (UC Berkeley) on behalf of the South Pole Telescope Collaboration:

In light of the updated error box provided by IPN, the millimeter-band transient event reported by the South Pole Telescope in GCN #34301 is no longer spatially consistent with GRB 230723A (Fermi GBM, GCN #34232; IPN, GCN #34258). The event remains an unexplained, short-duration millimeter-band transient not obviously associated with any known galactic source. 


GRB_name: GRB230802A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34313
SUBJECT: GRB 230802A: Swift detection of a burst
DATE:    23/08/02 07:08:39 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>


N. J. Klingler (GSFC/UMBC/CRESSTII), V. D'Elia (SSDC & INAF-OAR),
P. A. Evans (U Leicester), J. A. Kennea (PSU), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), A. Melandri (INAF-OAR),
K. L. Page (U Leicester), D. M. Palmer (LANL) and M. H. Siegel (PSU)
report on behalf of the Neil Gehrels Swift Observatory Team:

At 06:50:26 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 230802A (trigger=1182085).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 76.221, +19.570 which is 
   RA(J2000) = 05h 04m 53s
   Dec(J2000) = +19d 34' 10"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a wide pulse
structure with a duration of about 60 sec.  The peak count rate
was ~3000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 06:51:30.3 UT, 64.1 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 76.23952, 19.56147
which is equivalent to:
   RA(J2000)  = 05h 04m 57.48s
   Dec(J2000) = +19d 33' 41.3"
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This
location is 69 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at https://www.swift.ac.uk/sper. No
spectrum from the promptly downlinked event data is yet available to
determine the column density. 

The initial flux in the 2.5 s image was 1.25e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 73 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.614. 

Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB230802A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34317
SUBJECT: GRB 230802A: Enhanced Swift-XRT position
DATE:    23/08/02 20:19:42 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1180 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 230802A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 76.23985, +19.56066 which is equivalent
to:

RA (J2000): 05h 04m 57.56s
Dec (J2000): +19d 33' 38.4"

with an uncertainty of 2.0 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB230802A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34318
SUBJECT: GRB 230802A: Swift-XRT refined Analysis
DATE:    23/08/02 20:28:29 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

A.P. Beardmore (U. Leicester), B. Sbarufatti (INAF-OAB), A. D'Ai
(INAF-IASFPA), A. Melandri (INAF-OAR), J. D. Gropp (PSU), S. Dichiara
(PSU), J.A. Kennea (PSU), J.P. Osborne (U. Leicester) and P.A. Evans
report on behalf of the Swift-XRT team:

We have analysed 7.9 ks of XRT data for GRB 230802A, from 52 s to 40.1
ks after the  BAT trigger. The data comprise 386 s in Windowed Timing
(WT) mode (the first 10 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. 

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=0.4 (+/-0.4). At T+345 s  the decay
steepens to an alpha of 2.5 (+0.4, -0.3) before breaking again at
T+1364 s to a final decay with index alpha=1.26 (+0.16, -0.30).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.02 (+/-0.04). The
best-fitting absorption column is  6.5 (+/-0.5) x 10^21 cm^-2, in
excess of the Galactic value of 3.4 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.66 (+0.22, -0.21)
and a best-fitting absorption column of 4.5 (+1.5, -1.1) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.9 x 10^-11 (6.5 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.5 (+1.5, -1.1) x 10^21 cm^-2
Galactic foreground: 3.4 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.66 (+0.22, -0.21)

If the light curve continues to decay with a power-law decay index of
1.26, the count rate at T+24 hours will be 1.5 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.2 x
10^-14 (9.7 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01182085.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230802A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34320
SUBJECT: GRB 230802A: BOOTES-5/JGT optical upper limit
DATE:    23/08/02 21:00:30 GMT
FROM:    Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>

E. Fernandez-Garcia, Y.-D. Hu, A. J. Castro-Tirado, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy (IAA-CSIC), D. Hiriart and W. H. Lee (UNAM), C. J. Perez del Pulgar (UMA) and I. M. Carrasco-Garcia (SMA) and I. H. Park (SKKU), on behalf of a larger collaboration, report:

Following the detection of GRB 230802A by Swift (Klingler et al. GCNC 34313), the BOOTES-5/JGT 0.6m robotic telescope at Observatorio Astronomico Nacional in San Pedro Martir (Mexico) automatically observed the GRB location starting on Aug. 02, 11:41 UT (~ 4.9 h after trigger). No new optical source is detected on the co-added image (13 x 60 s, clear filter) within the enhanced Swift/XRT error region (Goad et al. GCNC 34317) down to 19.7 mag, which is consistent with the limit reported by UVOT (Klingler et al. GCNC 34313).

We thank the staff at Observatorio Astronomico Nacional in San Pedro Martir for their excellent support.


GRB_name: GRB230802A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34321
SUBJECT: Swift GRB 230802A: Global MASTER-Net observations report
DATE:    23/08/03 01:19:09 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was pointed to the Swift GRB 230802A ( N. J. Klingler et al., GCN 34313) errorbox  65651 sec after notice time and 65669 sec after trigger time at 2023-08-03 01:04:55 UT, with upper limit up to  15.3 mag. Observations started at twilight.  The observations began at zenith distance = 65 deg. The sun  altitude  is -13.8 deg. 

The galactic latitude b = -12 deg., longitude l = 183 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2248891

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   65759 |      MASTER-Tavrida |   C |   180 | 15.3 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230802B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34322
SUBJECT: GRB 230802B: Fermi GBM Final Localization
DATE:    23/08/03 01:25:55 GMT
FROM:    Joshua Wood at NASA/MSFC <joshua.r.wood@nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

"At 23:58:47.92 UT on 02 August 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230802B (trigger 712713532/230802999).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 22.22, Dec = 9.62 (J2000 degrees, equivalent to J2000 1h 28m, +9d 37'),
with a statistical uncertainty of 5.88 degrees.

The angle from the Fermi LAT boresight is 77 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230802999/quicklook/glg_skymap_all_bn230802999.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230802999/quicklook/glg_healpix_all_bn230802999.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230802999/quicklook/glg_lc_medres34_bn230802999.gif"


GRB_name: GRB230803A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34325
SUBJECT: GRB 230803A: Fermi GBM Final Real-time Localization
DATE:    23/08/03 01:37:47 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 01:27:08 UT on 3 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230803A (trigger 712718833.154354 / 230803061).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 158.4, Dec = -64.4 (J2000 degrees, equivalent to J2000 10h 33m, -64d 24'), with a statistical uncertainty of 3.3 degrees.

The angle from the Fermi LAT boresight is 66.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230803061/quicklook/glg_skymap_all_bn230803061.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230803061/quicklook/glg_healpix_all_bn230803061.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230803061/quicklook/glg_lc_medres34_bn230803061.gif


GRB_name: GRB230803A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34328
SUBJECT: GRB 230803A: AstroSat CZTI detection
DATE:    23/08/03 12:04:58 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>

P. K. Navaneeth (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the ML pipeline (Abraham et al., 2021, MNRAS, 504, 3084) and the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a bright long GRB 230803A which was also detected by Fermi (Fermi GBM Team, GCN Circ. 34325).

The source was clearly detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2023-08-03 01:28:42.50 UTC. The measured peak count rate associated with the burst is 783 (+56, -59) counts/s above the background in the combined data of all quadrants, with a total of 5492 (+498, -481) counts. The local mean background count rate was 430 (+3, -3) counts/s. Using cumulative rates, we measure a T90 of 25 (+2, -1) s. In the preliminary analysis, we find 371 Compton events associated with this event.

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2023-08-03 01:28:42.63 UTC. The measured peak count rate associated with the burst is 2196 (+97, -102) counts/s above the background in the combined data of all quadrants, with a total of 15329 (+934, -934) counts. The local mean background count rate was 1365 (+7, -5) counts/s. We measure a T90 of 26 (+2, -1) s from the cumulative Veto light curve.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at: 
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB230802A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34329
SUBJECT: GRB 230802A: Swift/UVOT Upper Limits
DATE:    23/08/03 13:59:26 GMT
FROM:    Sam LaPorte at PSU <sjl5346@psu.edu>

GRB 230802A: Swift/UVOT Upper Limits

S. J. LaPorte (PSU) and N. J. Klingler (GSFC/UMBC/CRESSTII)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230802A
73 s after the BAT trigger (Klingler et al., GCN Circ. 34313).
No optical afterglow consistent with the XRT position
(Evans et al., GCN Circ. 34317)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC            73          223          147         >20.0
u_FC               286          535          246         >19.5
white               73         1186          353         >20.5
v                  615         1581          117         >18.4
b                  541         1506           97         >19.2
u                  286         5048          492         >19.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.614 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB230803A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34330
SUBJECT: IPN triangulation of GRB 230803A
DATE:    23/08/03 20:39:17 GMT
FROM:    Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,

A. Ridnaia, D. Frederiks, D. Svinkin, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

A. Goldstein, M. S. Briggs, C. Wilson-Hodge,
and E. Burns on behalf of the Fermi GBM team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:

The long-duration GRB 230803A
(Fermi GBM detection: Fermi GBM team, GCN 34325;
AstroSat CZTI detection: Navaneeth et al., GCN 34328)
has been detected by Fermi (GBM), Konus-Wind,
INTEGRAL (SPI-ACS), AstroSat (CZTI), and
Mars-Odyssey (HEND), so far, at about 5228 s UT (01:27:08).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
  150.510 (10h 02m 02s) -64.987 (-64d 59' 12")
 Corners:
  147.455 (09h 49m 49s) -64.554 (-64d 33' 15")
  147.329 (09h 49m 19s) -64.581 (-64d 34' 51")
  153.688 (10h 14m 45s) -65.347 (-65d 20' 50")
  153.812 (10h 15m 15s) -65.315 (-65d 18' 54")
 ---------------------------------------------
The error box area is 431 sq. arcmin, and its maximum
dimension is 2.8 deg (the minimum one is 3 arcmin).
The Sun distance was 83 deg.

The IPN localization is consistent with, but reduces 
the area of, the Fermi-GBM final localization (GCN 34325).

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB230803_T05229/IPN/

The Konus-Wind time history and spectrum will be given
in a forthcoming GCN Circular.


GRB_name: GRB230804A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34332
SUBJECT: GRB 230804A: Fermi GBM Final Real-time Localization
DATE:    23/08/04 06:49:23 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 06:38:55 UT on 4 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230804A (trigger 712823940.838898 / 230804277).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 199.8, Dec = -45.2 (J2000 degrees, equivalent to J2000 13h 19m, -45d 12'), with a statistical uncertainty of 16.6 degrees.

The angle from the Fermi LAT boresight is 71.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230804277/quicklook/glg_skymap_all_bn230804277.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230804277/quicklook/glg_healpix_all_bn230804277.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230804277/quicklook/glg_lc_medres34_bn230804277.gif


GRB_name: GRB230802A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34333
SUBJECT: GRB 230802A: Swift-BAT refined analysis
DATE:    23/08/04 14:09:21 GMT
FROM:    Sibasish Laha at NASA-GSFC <slaha@umbc.edu>

S. D. Barthelmy (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC),D. M. Palmer (LANL),
T. Parsotan (GSFC/UMBC),T. Sakamoto (AGU),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):

Using the data set from T-240 to T+962 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 230802A (trigger #1182085)
(Klingler et al., GCN Circ. 34313).  The BAT ground-calculated position is
RA, Dec = 76.232, 19.552 deg which is
   RA(J2000)  =  05h 04m 55.6s
   Dec(J2000) = +19d 33' 06.3"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.

The BAT  light curve shows a complex structure with a duration of ~ 200 sec.
T90 (15-350 keV) is 175.62 +- 18.26 sec (estimated error including
systematics).

The time-averaged spectrum from T-6.04 to T+230.70 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
1.60 +- 0.07.  The fluence in the 15-150 keV band is 5.0 +- 0.2 x 10^-06
erg/cm2.
The 1-sec peak photon flux measured from T+0.60 sec in the 15-150 keV band
is 2.3 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1182085/BA/


GRB_name: GRB230802A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34334
SUBJECT: GRB 230802A: Fermi GBM observation
DATE:    23/08/04 15:39:21 GMT
FROM:    Joe Mangan at IJCLab <joseph.mangan@ijclab.in2p3.fr>

C. de Barra (UCD), J.Mangan (CNRS/IJCLab) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 06:50:22.23 UT on 2 August 2023, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 230802A (trigger 712651827 / 230802285),
which was also detected by Swift BAT (N. J. Klingler et al. 2023, GCN 34313).
The Fermi GBM on-ground location is consistent with the Swift BAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 107 degrees.

The GBM light curve consists of a single peak
with a duration (T90) of about 38 s (50-300 keV)The time-averaged spectrum from -14.3s to 26.6 s is
best fit by a simple power law function with index -1.7 +/- 0.02.

The event fluence (10-1000 keV) in this time interval is
(1.3 +/- 0.1)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+4.4 s in the 10-1000 keV band
is 5.6 +/- 0.4 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB230802B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34335
SUBJECT: GRB 230802B: AstroSat CZTI detection
DATE:    23/08/04 17:23:10 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>

B. Pari (IITB), P K. Navaneeth (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of GRB 230802B which was also detected by Fermi (Fermi GBM Team, GCN Circ. 34322).

The source was faintly detected in the 20-200 keV energy range in two quadrants. The light curve peaks at 2023-08-02 23:58:47.95 UTC. The measured peak count rate associated with the burst is 145.4 (+108.1, -8.4) counts/s above the background in the combined data of two quadrants, with a total of 169 (+54, -65) counts. The local mean background count rate was 151.0 (+5.2, -5.8) counts/s. Using cumulative rates, we measure a T90 of 2.7 (+0.8, -1.1) s. 

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at: 
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB230805A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34338
SUBJECT: GRB 230805A: Fermi GBM Final Real-time Localization
DATE:    23/08/05 07:26:53 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 07:16:16 UT on 5 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230805A (trigger 712912581.49606 / 230805303).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 44.7, Dec = 47.6 (J2000 degrees, equivalent to J2000 02h 58m, 47d 36'), with a statistical uncertainty of 6.5 degrees.

The angle from the Fermi LAT boresight is 77.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230805303/quicklook/glg_skymap_all_bn230805303.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230805303/quicklook/glg_healpix_all_bn230805303.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230805303/quicklook/glg_lc_medres34_bn230805303.gif


GRB_name: GRB230805B
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34339
SUBJECT: GRB 230805B: Swift detection of a burst
DATE:    23/08/05 11:49:08 GMT
FROM:    Jamie Kennea at Penn State U <jak51@psu.edu>


S. B. Cenko (GSFC), A. D'Ai (INAF-IASFPA),
V. D'Elia (SSDC & INAF-OAR), J.D. Gropp (PSU), J. A. Kennea (PSU),
H. A. Krimm (NSF), N. P. M. Kuin (UCL-MSSL), S. Laha (GSFC/UMBC) and
M. H. Siegel (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 11:23:51 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 230805B (trigger=1183217).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 207.747, +31.185 which is 
   RA(J2000) = 13h 50m 59s
   Dec(J2000) = +31d 11' 05"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 60 sec.  The peak count rate
was ~1300 counts/sec (15-350 keV), at ~5 sec after the trigger. 

The XRT began observing the field at 11:27:03.3 UT, 192.3 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 207.74281,
31.19102 which is equivalent to:
   RA(J2000)  = 13h 50m 58.28s
   Dec(J2000) = +31d 11' 27.7"
with an uncertainty of 1.9 arcseconds (radius, 90% containment). This
location is 25 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at https://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.41 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.6
(+2.86/-2.45) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 858 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. 
The 8'x8' region for the list of sources generated on-board covers 100% of the
XRT error circle. The list of sources is typically complete to about 18 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.014. 

Burst Advocate for this burst is S. B. Cenko (brad.cenko AT nasa.gov). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB230805B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34341
SUBJECT: Swift GRB 230805B: Global MASTER-Net observations report
DATE:    23/08/05 17:03:02 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 230805B ( S. B. Cenko et al., GCN 34339) errorbox  19680 sec after notice time and 19762 sec after trigger time at 2023-08-05 16:53:13 UT, with upper limit up to  16.6 mag. Observations started at twilight.  The observations began at zenith distance = 66 deg. The sun  altitude  is -10.7 deg. 

The galactic latitude b = 76 deg., longitude l = 52 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2250484

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   19853 |         MASTER-SAAO |   C |   180 | 16.6 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230805B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34343
SUBJECT: GRB 230805B: SAO RAS optical observations
DATE:    23/08/05 20:40:08 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin (SAO RAS) and V. P. Goranskij (SAI MSU) report
on behalf of a larger collaboration.

We observed the field of the GRB 230805B (Cenko et al., GCNC #34339)
with the 1-m telescope of SAO RAS Zeiss-1000 equipped with the
Multi-Mode Photometer-Polarimeter (MMPP). We obtained 4 x 300 sec.
exposures in Rc band on August 5, 17:50:15--18:11:48 UT.

Within the XRT error circle we marginally detected a single object
(possible OT) with coordinates (Epoch = 2000.0):
R.A. = 13:50:58.2, Dec. = +31:11:28.6 (+/- 0".5)
and brightness about R = 22.7 +/- 0.3 (t_mid - t0 = 6.61 hours).

This preliminary photometry is based on the nearby SDSS stars;
magnitudes are converted using Lupton (2005) equations.


GRB_name: GRB230805A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34344
SUBJECT: Fermi GRB 230805A: Global MASTER-Net observations report
DATE:    23/08/05 20:45:51 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-Tunka robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 230805A ( Fermi GBM team, GCN 34338) errorbox  23358 sec after notice time and 23391 sec after trigger time at 2023-08-05 13:46:07 UT, with upper limit up to  14.1 mag. Observations started at twilight.  The observations began at zenith distance = 76 deg. The sun  altitude  is -8.4 deg. 

The galactic latitude b = -9 deg., longitude l = 145 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2250244

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   23421 | 2023-08-05 13:46:07 |        MASTER-Tunka | (02h 45m 41.38s , +46d 10m 48.2s) |   C |    60 | 14.1 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230805B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34345
SUBJECT: GRB 230805B: Swift-XRT refined Analysis
DATE:    23/08/05 21:19:54 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAR), T. Sbarrato (INAF-OAB),
S. Dichiara (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), J.P.
Osborne (U. Leicester), K.L. Page (U. Leicester) and P.A. Evans report
on behalf of the Swift-XRT team:

We have analysed 6.0 ks of XRT data for GRB 230805B, from 210 s to 25.0
ks after the  BAT trigger. The data are entirely in Photon Counting
(PC) mode. The best available XRT position  (using the promptly
downlinked event data, the XRT-UVOT alignment and matching UVOT field
sources to the USNO-B1 catalogue) is RA, Dec = 207.74271, 31.19102
which is equivalent to:

RA (J2000): 13 50 58.25
Dec(J2000): +31 11 27.7

with an uncertainty of 1.9 arcsec (radius, 90% confidence).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=3.7 (+0.9, -0.4). At T+650 s  the decay
flattens to an alpha of -0.22 (+0.72, -0.08) before breaking again at
T+4027 s to a final decay with index alpha=1.7 (+0.6, -0.5).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.76 (+0.26, -0.24). The
best-fitting absorption column is  8.9 (+7.5, -6.2) x 10^20 cm^-2, in
excess of the Galactic value of 1.4 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.8 x 10^-11 (4.4 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      8.9 (+7.5, -6.2) x 10^20 cm^-2
Galactic foreground: 1.4 x 10^20 cm^-2
Excess significance: 2.0 sigma
Photon index:      1.76 (+0.26, -0.24)

If the light curve continues to decay with a power-law decay index of
1.7, the count rate at T+24 hours will be 5.6 x 10^-4 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.1 x
10^-14 (2.5 x 10^-14) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01183217.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230805B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34346
SUBJECT: GRB 230805B: NOT optical afterglow confirmation
DATE:    23/08/05 22:58:50 GMT
FROM:    Daniele B. Malesani at IMAPP / Radboud University <d.malesani@astro.ru.nl>

D. B. Malesani (Radboud Univ. and DAWN/NBI) and T. Pursimo (NOT) report on behalf of a larger collaboration:

We observed the location of GRB 230805B (Cenko et al., GCN 34339) using the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. Observations were secured in the r and z bands. An object with position consistent with the one reported by Moskvitin & Goranskij (GCN 34343) is well detected in our data. Based on nearby stars from the Gaia catalog, we measure the following J2000 coordinates, with an error of ~0.3":

RA  = 13:50:58.23
Dec = +31:11:28.6

At a mean epoch 2023 Aug 5.91 UT (10.4 hr after the trigger), we measure a preliminary magnitude (calibrated against nearby Pan-STARRS point-like sources) r = 23.5 +- 0.15 AB. Compared to the measurement by Moskvitin & Goranskij (GCN 34343), our magnitude value provides 2-sigma evidence for fading, consistent with afterglow behavior.


GRB_name: GRB230805B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34347
SUBJECT: GRB 230805B: BOOTES-6/DPRT optical upper limit and 1.5m OSN detection
DATE:    23/08/06 03:15:01 GMT
FROM:    Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>

Y.-D. Hu, I. Perez-Garcia, E. Fernandez-Garcia, A. J. Castro-Tirado, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy and F. J. Aceituno (IAA-CSIC), P. J. Meintjes and H. Van Heerden (UFS, SouthAfrica), A. Martin-Carrillo and L. Hanlon (UCD, Ireland), M. Gritsevich (Univ. of Helsinki) and C. J. Perez del Pulgar (UMA), on behalf of a larger collaboration, report:

Following the detection of GRB 230805B by Swift (Cenko et al. GCNC 34339), the BOOTES-6/DPRT 0.6m robotic telescope at Boyden Observatory in Maselspoort (South Africa) automatically observed the GRB location starting on Aug. 05, 17:15 UT (~ 5.9 h after trigger). No new optical source is detected on the co-added image (7 x 60 s, clear filter) within the enhanced Swift/XRT error region (D'Ai et al. GCNC 34345) down to 19.9 mag.

We also triggered the 1.5m telescope at Observatorio de Sierra Nevada in Granada (Spain), starting on Aug. 05, 20:30 UT (~ 9.1 h after trigger). At the position of the suggested optical afterglow reported by Moskvitin and Goranskij (GCNC 34343) we found a faint optical source for which we preliminary measure I = 22.9+/-0.4 (on a 12 x 150s co-added image), consistent with the fading reported by Malesani and Pursimo in the r-band (GCNC 34346).

We thank both the staff at Boyden and Sierra Nevada Observatories for their excellent support.


GRB_name: GRB230805B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34349
SUBJECT: GRB  230805B: Bassano Bresciano observatory upper limit
DATE:    23/08/06 07:04:21 GMT
FROM:    Ulisse Quadri at Bassano Bresciano Obs <oabb@ulisse.bs.it>

U.Quadri and  L.Strabla (Bassano Bresciano Astronomical Observatory),
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report: 

We imaged the field of GRB 230805B detected by SWIFT(trigger 1183217)
with the robotic telescope of (IAU station 565) Bassano Bresciano 
Observatory, Italy. Member of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
GAC - Gruppo Astrofili Cremonesi.

The observations started 8.74 hour after the GRB trigger, At the end of twilight 
with our Newton telescope D=250 mm F/D=4.8.

Weather conditions were good.

We co-added 4 series of 20 exposures of 60 sec each.

Start T0+      End T0+     CR lim
8.74 hour   10.00 hour      19.5

CR is unfiltered with R zero point

We did not found any optical counterpart in the error box of the XRTcandidate.
S. B. Cenko (GSFC) et al. GCN 34339

Magnitudes were estimated with the USNO-B1.0 cat. and 
are not corrected for galactic dust extinction.

Reference:
http://www.osservatoriobassano.org/GRB.asp

The message may be cited.


GRB_name: GRB230805B
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34351
SUBJECT: GRB 230805B: Swift/UVOT Upper Limits
DATE:    23/08/06 18:02:19 GMT
FROM:    Sam LaPorte at PSU <sjl5346@psu.edu>

GRB 230805B: Swift/UVOT Upper Limits

S. J. LaPorte (PSU) and S. B. Cenko (GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230805B
196 s after the BAT trigger (Cenko et al., GCN Circ. 34339).
No optical afterglow consistent with the XRT position
(Evans et al., GCN Circ. 34345)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           196          345          147         >20.2
u_FC               354          604          246         >19.5
white              196         1878          284         >20.7
v                  683         1927          135         >19.0
b                  610         1854          136         >20.4
u                  354         1829          363         >19.6
w1                 732         1804          117         >19.4
w2                1014         1730           58         >18.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.014 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB230805B
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34353
SUBJECT: GRB 230805B: Enhanced Swift-XRT position
DATE:    23/08/06 21:46:11 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 3447 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 230805B, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 207.74318, +31.19135 which is equivalent
to:

RA (J2000): 13h 50m 58.36s
Dec (J2000): +31d 11' 28.8"

with an uncertainty of 2.1 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB230806A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34354
SUBJECT: GRB 230806A: Fermi GBM Final Localization
DATE:    23/08/07 00:36:33 GMT
FROM:    Peter Veres at University of Alabama in Huntsville <veresp@gmail.com>


The Fermi GBM team reports the detection of a likely SHORT GRB

"At 04:02:32.37 UT on 06 August 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230806A (trigger 712987357/230806168).

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 63.12, Dec = -7.33 (J2000 degrees, equivalent to J2000 4h 12m, -7d 19'),
with a statistical uncertainty of 18.10 degrees.

The angle from the Fermi LAT boresight is 64 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230806168/quicklook/glg_skymap_all_bn230806168.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230806168/quicklook/glg_healpix_all_bn230806168.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230806168/quicklook/glg_lc_medres34_bn230806168.gif"


GRB_name: GRB230805B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34356
SUBJECT: GRB 230805B : OHP/T193 optical upper limit
DATE:    23/08/07 13:34:31 GMT
FROM:    Damien Turpin at CEA-Saclay <dturpin-astro@hotmail.com>

D. Turpin (CEA Paris-Saclay), C. Adami (LAM), B. Schneider (MIT),
E. Le Floc'h, D. GÃ¶tz, F. SchÃ¼ssler (CEA Paris-Saclay), A. de Ugarte Postigo (OCA/CNRS),
S. Basa (LAM), S. D. Vergani (GEPI, Obs. de Paris), report on behalf
of a larger collaboration:

We observed the field of GRB 230805B (Cenko et al., GCN 34339; D'Ali et al.,
GCN 34345; LaPorte et al., GCN 34251; Osborne et al. GCN 34353)
using the T193cm telescope at Observatoire de Haute-Provence (France)
equipped with the MISTRAL spectro-imager. In 5 exposures, obtained
in the r-band (5x600s) from 2023 05 August 20:36:08 UT to
21:34:34 UT (mid-time ~9.69h after trigger) under poor seeing conditions,
we do not detect any source at the position reported by
Moskvitin et al., GCN 34343; Malesani et al., GCN 34346; Hu et al., GCN 34347
down to the following 5-sigma limit:

r > 21.5 mag (AB)

The photometric calibration was performed using nearby stars from
the PanSTARRS catalog and the magnitude is not corrected for Galactic
extinction.

We acknowledge the excellent support from Observatoire de Haute-Provence,
in particular Jean Balcaen for the MISTRAL observations and
the SOPHIE observer Lisa Altinier. 


GRB_name: GRB230805B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34357
SUBJECT: GRB 230805B: Fermi GBM observation
DATE:    23/08/07 14:40:05 GMT
FROM:    Joe Mangan at IJCLab <joseph.mangan@ijclab.in2p3.fr>

J.Mangan (CNRS/IJCLab) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:

"At 11:23:33.59 UT on 05 August 2023, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 230805B (trigger 712927418 / 230805475),
which was also detected by Swift BAT (S. B. Cenko et al. 2023, GCN 34339).
The Fermi GBM on-ground location is consistent with the Swift BAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 48 degrees.

The GBM light curve consists of multiple emissions
with a duration (T90) of about 60 s (50-300 keV).
The time-averaged spectrum from T0-0 s to T0+60.5 s is best fit by
a simple power law function with index -1.4 +/- 0.03

The event fluence (10-1000 keV) in this time interval is
(4.8 +/- 0.3)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+-0.1 s in the 10-1000 keV band
is 2.3 +/- 0.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary; 
final results will be published in the GBM GRB Catalog: 
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html
 
For Fermi GBM data and info, please visit the official Fermi GBM Support Page: 
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB230803A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34358
SUBJECT: Konus-Wind detection of GRB 230803A
DATE:    23/08/07 15:47:20 GMT
FROM:    Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>

D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 230803A (Fermi GBM detection: Fermi GBM team, GCN 34325;
AstroSat CZTI detection: Navaneeth et al., GCN 34328;
IPN triangulation: Kozyrev et al., GCN 34330)
triggered Konus-Wind (KW) at T0=5229.064 s UT (01:27:09.064).

The burst light curve shows a multi-peaked structure
with a total duration of ~126 s.
The emission is seen up to ~2 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB230803_T05229/

As observed by Konus-Wind, the burst had
a fluence of (7.59 Â± 0.88)x10^-5 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 93.760 s,
of (1.43 Â± 0.13)x10^-5 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0+57.600 to T0+128.256 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -1.30 (-0.06,+0.08),
the high energy photon index beta = -2.65 (-0.82,+0.30),
the peak energy Ep = 256 (-31,+32) keV,
chi2 = 112/97 dof.

The spectrum near the peak count rate (measured from T0+90.368 to T0+95.488 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.93 (-0.06,+0.07),
the high energy photon index beta = -2.32 (-0.20,+0.14),
the peak energy Ep = 284 (-38,+40) keV,
chi2 = 66/77 dof.

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB230807A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34361
SUBJECT: GRB 230807A: Fermi GBM Final Real-time Localization
DATE:    23/08/07 22:35:36 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 22:25:01 UT on 7 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230807A (trigger 713139906.818582 / 230807934).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 73.3, Dec = -51.0 (J2000 degrees, equivalent to J2000 04h 53m, -51d 00'), with a statistical uncertainty of 3.5 degrees.

The angle from the Fermi LAT boresight is 96.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230807934/quicklook/glg_skymap_all_bn230807934.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230807934/quicklook/glg_healpix_all_bn230807934.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230807934/quicklook/glg_lc_medres34_bn230807934.gif


GRB_name: GRB230807A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34363
SUBJECT: Fermi GRB 230807A: Global MASTER-Net observations report
DATE:    23/08/08 00:45:47 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 230807A ( Fermi GBM team, GCN 34361) errorbox  740 sec after notice time and 775 sec after trigger time at 2023-08-07 22:37:57 UT, with upper limit up to  18.1 mag. The observations began at zenith distance = 80 deg. The sun  altitude  is -74.3 deg. 

The galactic latitude b = -39 deg., longitude l = 258 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2251439

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

     805 | 2023-08-07 22:37:57 |         MASTER-SAAO | (04h 52m 47.80s , -51d 03m 55.2s) |   C |    60 | 17.3 |        
     865 | 2023-08-07 22:37:57 |         MASTER-SAAO | (04h 52m 47.80s , -51d 03m 55.2s) |   C |   180 | 17.9 |  Coadd 
     805 | 2023-08-07 22:37:57 |         MASTER-SAAO | (04h 51m 35.23s , -51d 03m 20.2s) |   C |    60 | 17.4 |        
     865 | 2023-08-07 22:37:57 |         MASTER-SAAO | (04h 51m 35.21s , -51d 03m 20.2s) |   C |   180 | 18.1 |  Coadd 
     885 | 2023-08-07 22:39:16 |         MASTER-SAAO | (04h 52m 47.69s , -51d 02m 55.7s) |   C |    60 | 17.2 |        
     885 | 2023-08-07 22:39:16 |         MASTER-SAAO | (04h 51m 35.14s , -51d 02m 20.1s) |   C |    60 | 17.3 |        
     977 | 2023-08-07 22:40:48 |         MASTER-SAAO | (04h 52m 53.74s , -51d 03m 56.6s) |   C |    60 | 17.3 |        
     977 | 2023-08-07 22:40:48 |         MASTER-SAAO | (04h 51m 41.02s , -51d 03m 21.5s) |   C |    60 | 17.4 |        
    1067 | 2023-08-07 22:42:19 |         MASTER-SAAO | (04h 52m 46.43s , -51d 04m 58.9s) |   C |    60 | 16.9 |        
    1067 | 2023-08-07 22:42:19 |         MASTER-SAAO | (04h 51m 33.61s , -51d 04m 23.3s) |   C |    60 | 17.1 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230805B
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34368
SUBJECT: GRB 230805B : MITSuME Akeno optical upper limits
DATE:    23/08/08 10:29:05 GMT
FROM:    Narikazu Higuchi at Tokyo Tech <higuchi@hp.phys.titech.ac.jp>

N. Higuchi, I. Takahashi, M. Sasada, M. Niwano, S. Sato, S. Hayatsu, R. Hosokawa, H. Seki, H. Takei, Y. Yatsu (Tokyo Tech) and N. Kawai (Riken) report on behalf of the MITSuME collaboration:

We observed the field of GRB 230805B (Cenko et al. GCN Circular #34339) with the optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope Akeno. 

The observation started at 2023-8-05 11:25:51 UT (120 seconds after the Swift/BAT trigger). We stacked the images with good conditions. We did not detect any uncatalogued sources within the error region (Osborne et al. GCN Circular #34353). We obtained the 5-sigma limits of the stacked images as follows.

T0+[sec] | MID-UT | T-EXP[sec] | 5-sigma limits
------------------------------------------------------------------------------------------------
1117 | 2023-08-05 11:42:28 | 240.0 | g'>18.5, Rc>18.5, Ic>17.9
4357 | 2023-08-05 12:36:28 | 840.0 | g'>18.9, Rc>19.0, Ic>18.5
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time

We used the PS1 catalog for flux calibration. The catalog magnitudes in PS1 g, r and i bands were converted to our g', Rc and Ic band magnitudes following Tonry et al. (2012), Table 6. The magnitudes are expressed in the AB system. The images were processed in real-time through the MITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73, Issue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).


GRB_name: GRB230808A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34369
SUBJECT: GRB 230808A: Fermi GBM Final Real-time Localization
DATE:    23/08/08 10:59:45 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 10:49:12 UT on 8 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230808A (trigger 713184557.782692 / 230808451).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 81.6, Dec = 58.5 (J2000 degrees, equivalent to J2000 05h 26m, 58d 30'), with a statistical uncertainty of 2.2 degrees.

The angle from the Fermi LAT boresight is 36.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230808451/quicklook/glg_skymap_all_bn230808451.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230808451/quicklook/glg_healpix_all_bn230808451.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230808451/quicklook/glg_lc_medres34_bn230808451.gif


GRB_name: GRB230808B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34373
SUBJECT: GRB 230808B: Fermi GBM Final Real-time Localization
DATE:    23/08/08 18:50:46 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 16:46:11 UT on 8 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230808B (trigger 713205976.382378 / 230808699).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 204.7, Dec = -22.2 (J2000 degrees, equivalent to J2000 13h 38m, -22d 11'), with a statistical uncertainty of 2.4 degrees.

The angle from the Fermi LAT boresight is 48.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230808699/quicklook/glg_skymap_all_bn230808699.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230808699/quicklook/glg_healpix_all_bn230808699.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230808699/quicklook/glg_lc_medres34_bn230808699.gif


GRB_name: GRB230808A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34375
SUBJECT: GRB 230808A: Swift/BAT-GUANO detection of a burst
DATE:    23/08/08 21:34:24 GMT
FROM:    Jimmy DeLaunay at University of Alabama  <delauj2@gmail.com>

James DeLaunay (UAlabama), Gayathri Raman (PSU), Samuele Ronchini (PSU), Aaron Tohuvavohu (U Toronto), Jamie A. Kennea (PSU), Tyler Parsotan (NASA GSFC) report:

Swift/BAT did not localize GRB 230808A onboard (T0: 2023-08-08T10:49:12.78 UTC, Fermi GBM Trig 713184557, GCN 34369). 

The Fermi notice, distributed in near real-time, triggered the Swift Mission Operations Center operated Gamma-ray Urgent Archiver for Novel Opportunities (GUANO; Tohuvavohu et al. 2020, ApJ, 900, 1). 

Upon trigger by this notice, GUANO sent a command to the Swift Burst Alert Telescope (BAT) to save 200 seconds of BAT event-mode data from [-50,+150] seconds around the time of the burst. All the requested event mode data was delivered to the ground.

The BAT likelihood search, NITRATES (DeLaunay + Tohuvavohu 2022, ApJ, 941, 169), detects the burst with a sqrt(TS) of 9.6 in a 16.384 s analysis time bin, starting at T0 + 16.384 s.

NITRATES results, independently, are ambiguous with respect to whether this burst originates from in or outside the BAT coded FOV, with a DeltaLLHOut of 12.1.
The Fermi GBM localization (GCN 34369) has this burst significantly outside of the BAT coded FOV

See Section 9.1 and Figures 10 and 17 in the NITRATES paper for brief descriptions and interpretation of sqrt(TS), DeltaLLHPeak, and DeltaLLHOut.

GUANO is a fully autonomous, extremely low latency, spacecraft
commanding pipeline designed for targeted recovery of BAT event mode
data around the times of compelling astrophysical events to enable
more sensitive GRB searches.

A live reporting of Swift/BAT event data recovered by GUANO can be
found at: https://www.swift.psu.edu/guano/


GRB_name: GRB230805B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34376
SUBJECT: GRB 230805B: AstroSat CZTI detection
DATE:    23/08/09 15:43:08 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>

P. K. Navaneeth (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long GRB 230805B which was also detected by Swift-BAT (Cenko et al., GCN Circ. 34339), and Fermi-GBM (Mangan et al., GCN Circ. 34357).

The source was detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2023-08-05 11:23:33.50 UTC. The measured peak count rate associated with the burst is 165 (+36, -38) counts/s above the background in the combined data of three quadrants (out of four), with a total of 1304 (+507, -508) counts. The local mean background count rate was 337 (+1, -2) counts/s. Using cumulative rates, we measure a T90 of 54 (+27, -25) s. 

The source was also detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at: 
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB230805B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34377
SUBJECT: GRB 230805B: Iota Scorpii Observatory, La Spezia, Italy upper limit
DATE:    23/08/09 19:55:18 GMT
FROM:    GIULIO SCARFI at IOTA SCORPII OBSERVATORY <terziaria@gmail.com>

Giulio ScarfÃ¬ (Gruppo Astronomia Digitale - Iota Scorpii Observatory, La
Spezia,
Italy)
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan),
Y. Niino (Tokyo University, Institute of Astronomy),
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
Unione Astrofili Italiani (UAI)
report:

We imaged the field of GRB 230805B detected by SWIFT(trigger 11:23:51 UT)
with the telescope GSO 16â€ of Iota Scorpii Observatory, La Spezia Italy

Member of:

UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili, GRB section.
GAD - Gruppo Astronomia Digitale.

The observations started 550 min after the GRB trigger, at the end of
twilight,
with a Ritchey Cretien D=406 mm with reducer F/D=6,15.
Weather conditions were very good.

We co-added 6 exposures of 300 sec each.


Start T0+      End T0+       R lim
550 min        581 min         20


We did not found any optical counterpart in the error box of the XRT
candidate.
Page et al. GCN 34339

Magnitudes were estimated with the Gaia EDR3 cat. and
are not corrected for galactic dust extinction. 20.0

Reference:
https://www.parcodellestelle.com/

The message may be cited.


GRB_name: GRB230805B
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34379
SUBJECT: GRB 230805B: Swift-BAT refined analysis
DATE:    23/08/10 16:51:21 GMT
FROM:    Sibasish Laha at NASA-GSFC <slaha@umbc.edu>

H. A. Krimm (NSF), S. D. Barthelmy (GSFC),
S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC),D. M. Palmer (LANL),
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):

Using the data set from T-40 to T+200 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 230805B (trigger #1183217)
(Cenko et al., GCN Circ. 34339).  The BAT ground-calculated position is
RA, Dec = 207.738, 31.190 deg which is
   RA(J2000)  =  13h 50m 57.2s
   Dec(J2000) = +31d 11' 23.0"
with an uncertainty of 2.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 41%.

The BAT  light curve shows a complex structure with a duration of ~ 100 sec.
T90 (15-350 keV) is 93.77 +- 18.83 sec (estimated error including
systematics).

The time-averaged spectrum from T-21.60 to T+103.27 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
1.36 +- 0.20.  The fluence in the 15-150 keV band is 1.9 +- 0.2 x 10^-06
erg/cm2.
The 1-sec peak photon flux measured from T-17.66 sec in the 15-150 keV band
is 1.2 +- 0.3 ph/cm2/sec.  All the quoted errors are at the 90% confidence
level.

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1183217/BA/


GRB_name: GRB230808A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34381
SUBJECT: GRB 230808A: Fermi GBM Detection
DATE:    23/08/11 15:01:08 GMT
FROM:    Ava Myers at NASA GSFC <ava.myers@nasa.gov>

A. Myers (NPP/GSFC) and S. Lesage (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

â€œAt 10:49:12.78 UT on 08 August 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230808A (trigger 713184557/230808451, which was also detected by Swift/BAT-GUANO (B. Person et al. 2020; GCN 34375 reported by James Delaunay). The Fermi GBM Final Real-time Localization was reported at GCN 34369.

The angle from the Fermi LAT boresight is 36 degrees.

The GBM light curve consists of a multiple-emission episode with a duration (T90) of about 62 s (50-300 keV). The time-averaged spectrum from T0-4.6 to T0+69.1 s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.07 +/- 0.06 and the cutoff energy, parameterized as Epeak, is 430 +/- 60 keV.

The event fluence (10-1000 keV) in this time interval is (1.31 +/- 0.06)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+18 s in the 10-1000 keV band is 6.4 +/- 0.3 ph/s/cm^2.

The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB230812A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34383
SUBJECT: GRB 230812A: Fermi GBM Final Real-time Localization
DATE:    23/08/12 09:39:02 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 09:28:32 UT on 12 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230812A (trigger 713525317.441558 / 230812395).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 294.2, Dec = -32.2 (J2000 degrees, equivalent to J2000 19h 36m, -32d 12'), with a statistical uncertainty of 4.5 degrees.

The angle from the Fermi LAT boresight is 71.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230812395/quicklook/glg_skymap_all_bn230812395.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230812395/quicklook/glg_healpix_all_bn230812395.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230812395/quicklook/glg_lc_medres34_bn230812395.gif


GRB_name: GRB230812B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34386
SUBJECT: GRB 230812B: Fermi GBM Final Real-time Localization
DATE:    23/08/12 19:08:45 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 18:58:12 UT on 12 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230812B (trigger 713559497.049606 / 230812790).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 250.1, Dec = 46.2 (J2000 degrees, equivalent to J2000 16h 40m, 46d 12'), with a statistical uncertainty of 1.0 degrees.

The angle from the Fermi LAT boresight is 29.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230812790/quicklook/glg_skymap_all_bn230812790.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230812790/quicklook/glg_healpix_all_bn230812790.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230812790/quicklook/glg_lc_medres34_bn230812790.gif


GRB_name: GRB230812B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34387
SUBJECT: GRB 230812B: Fermi GBM detection of an extremely bright GRB
DATE:    23/08/12 19:51:19 GMT
FROM:    Stephen Lesage at Fermi-GBM Team <sjl0014@uah.edu>

S. Lesage (UAH), E. Burns (LSU), S. Dalessi (UAH), and O. Roberts (USRA)
report on behalf of the Fermi GBM Team:

"At 18:58:12 UT on 12 August 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230812B (trigger 713559497/230812790).

The GBM light curve consists of an extremely bright short pulse, with the bulk of the emission during the first 2 seconds, and continued emission out to roughly 20 seconds. This event, if it is a GRB, it is extremely bright and follow-up across all wavelengths is encouraged.

The on-ground calculated location, using the Fermi GBM trigger data,
is RA = 250.06, Dec = 46.20 (J2000 degrees, equivalent to J2000 16h 40m, +46d 12'), with a statistical uncertainty of 1.00 degree
(radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ).

The angle from the Fermi LAT boresight is 29 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230812790/quicklook/glg_skymap_all_bn230812790.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230812790/quicklook/glg_healpix_all_bn230812790.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230812790/quicklook/glg_lc_medres34_bn230812790.gif"


GRB_name: GRB230812B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34388
SUBJECT: GRB 230812B: Tiled Swift observations
DATE:    23/08/12 21:10:34 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>


P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a series of observations, tiled on the sky, of the
Fermi/GBM GRB 230812B. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00115

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. The probability of finding
serendipitous sources, unrelated to the Fermi/GBM event is high: any X-ray source
considered to be a probable afterglow candidate will be reported via a GCN Circular
after manual consideration.

Details of the XRT automated analysis methods are detailed in Evans et
al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230812B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34389
SUBJECT: Fermi GRB 230812B: Global MASTER-Net observations report
DATE:    23/08/12 22:31:08 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 230812B ( Fermi GBM team, GCN 34386) errorbox  10680 sec after notice time and 10713 sec after trigger time at 2023-08-12 21:56:45 UT, with upper limit up to  19.3 mag. The observations began at zenith distance = 50 deg. The sun  altitude  is -31.0 deg. 

The galactic latitude b = 41 deg., longitude l = 72 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2253499

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   10804 | 2023-08-12 21:56:45 |      MASTER-Tavrida | (16h 41m 41.24s , +46d 23m 36.1s) |   C |   180 | 19.3 |        
   10992 | 2023-08-12 21:59:54 |      MASTER-Tavrida | (16h 41m 46.04s , +46d 22m 29.1s) |   C |   180 | 19.1 |        
   11111 | 2023-08-12 22:03:07 |      MASTER-Tavrida | (16h 41m 40.73s , +46d 21m 24.6s) |   C |    30 | 17.8 |        
   11151 | 2023-08-12 22:03:47 |      MASTER-Tavrida | (16h 41m 47.62s , +46d 21m 41.9s) |   C |    30 | 17.8 |        
   11189 | 2023-08-12 22:04:25 |      MASTER-Tavrida | (16h 41m 44.53s , +46d 23m 10.6s) |   C |    30 | 17.9 |        
   11227 | 2023-08-12 22:05:04 |      MASTER-Tavrida | (16h 41m 44.48s , +46d 21m 32.8s) |   C |    30 | 17.8 |        
   11267 | 2023-08-12 22:05:43 |      MASTER-Tavrida | (16h 41m 47.52s , +46d 22m 59.5s) |   C |    30 | 17.8 |        
   11304 | 2023-08-12 22:06:21 |      MASTER-Tavrida | (16h 41m 40.68s , +46d 22m 18.0s) |   C |    30 | 17.8 |        
   11343 | 2023-08-12 22:06:59 |      MASTER-Tavrida | (16h 41m 41.50s , +46d 23m 16.6s) |   C |    30 | 18.0 |        
   11381 | 2023-08-12 22:07:38 |      MASTER-Tavrida | (16h 41m 47.28s , +46d 22m 15.3s) |   C |    30 | 17.8 |        
   11495 | 2023-08-12 22:08:17 |      MASTER-Tavrida | (16h 39m 42.09s , +46d 39m 09.7s) |   C |   180 | 19.0 |        
   11683 | 2023-08-12 22:11:25 |      MASTER-Tavrida | (16h 39m 49.58s , +46d 39m 04.4s) |   C |   180 | 19.0 |        
   11874 | 2023-08-12 22:14:36 |      MASTER-Tavrida | (16h 41m 28.89s , +45d 40m 34.6s) |   C |   180 | 19.0 |        
   12063 | 2023-08-12 22:17:44 |      MASTER-Tavrida | (16h 41m 29.14s , +45d 39m 21.9s) |   C |   180 | 19.0 |        
   12251 | 2023-08-12 22:20:53 |      MASTER-Tavrida | (16h 41m 31.63s , +45d 40m 21.9s) |   C |   180 | 19.0 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230812B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34391
SUBJECT: GRB 230812B: Fermi GBM Observation of a very bright burst
DATE:    23/08/13 01:41:45 GMT
FROM:    Oliver J Roberts at USRA/NASA <oliver.roberts@nasa.gov>

O.J. Roberts (USRA), C. Meegan (UAH), S. Lesage (UAH), E. Burns (LSU), and S. Dalessi (UAH) 
report on behalf of the Fermi GBM Team:

"At 18:58:12.05 UT on 12 August 2023, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 230812B (trigger 713559497 / 230812790). The Fermi 
GBM Final Real-time Localization was previously reported (GBM team 2023, GCN 34386). 

The angle from the Fermi LAT boresight at the GBM trigger time is 29 degrees.

The GBM light curve consists of a FRED-like burst with a duration (T90)
of about 3 s (10-1000 keV). The time-averaged spectrum over the whole burst
from T0-1s to T0+32 s is best fit by a Band function with Epeak = 273 +/- 3 keV,  
alpha of -0.80 +/- 0.01 and beta of -2.47 +/-0.02.

The event fluence (10-1000 keV) in this time interval is
(2.5201 +/- 0.0002)E-04 erg/cm^2. The 1s peak photon flux measured
starting from T0+0.6 s in the 10-1000 keV band is 740 +/- 2 ph/s/cm^2.

Due to a timing glitch in the middle of the burst in the TTE data, this data
type had to be reprocessed and consequently, this preliminary report used the 
CSPEC and CTIME data types only, which were unaffected. We note that due
to the intensity of the burst, pulse pile-up during the burst is highly likely.
This analysis is ongoing. 

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB230812B
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34392
SUBJECT: GRB 230812B: Fermi-LAT detection
DATE:    23/08/13 02:50:20 GMT
FROM:    Lorenzo Scotton at UAH <lscottongcn@outlook.com>

L. Scotton (UAH), D. Kocevski (NASA/MSFC), J. Racusin (NASA/GSFC), and N. Omodei (Stanford University)
report on behalf of the Fermi-LAT Collaboration:

On August 12, 2023, Fermi-LAT detected high-energy emission from
GRB 230812B, which was also detected by Fermi-GBM (trigger 713559497/230812790, S. Lesage GCN 34387, O. Roberts GCN 34391).

The best LAT on-ground location is found to be

RA, Dec = 249.10, 47.75 (degrees, J2000)

with an error radius of 0.13 deg (90% containment, statistical error only).
This was 29 deg from the LAT boresight at the time of the GBM trigger:

T0 = 18:58:12.05 UT.

The data from the Fermi-LAT show a significant increase
in the event rate after the GBM trigger that is spatially correlated with the
GBM emission (1.69 degrees from the GBM location) with high significance.
The photon flux above 100 MeV in the time interval 0-50 s after the
GBM trigger is (1.96 +/- 0.27)E-4 ph/cm2/s.

The estimated photon index above 100 MeV is -2.16 +/- 0.14.

The highest-energy photon is a 72 GeV event which is observed 32.2 seconds
after the GBM trigger.

The Fermi-LAT point of contact for this burst is
Lorenzo Scotton (lorenzo.scotton AT uah.edu).

The Fermi-LAT is a pair conversion telescope designed to cover
the energy band from 20 MeV to greater than 300 GeV.
It is the product of an international collaboration between
NASA and DOE in the U.S. and many scientific institutions
across France, Italy, Japan and Sweden.


GRB_name: GRB230812B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34393
SUBJECT: GRB 230812B: Preliminary Swift/XRT localization
DATE:    23/08/13 04:03:06 GMT
FROM:    Jamie Kennea at Penn State U <jak51@psu.edu>

J. A. Kennea (PSU) on behalf ot the Swift team,

In a target-of-opportunity observation taken starting 02:00UT on  
August 13th, 2023, pointed at the LAT position (GCN 34392) of 
GRB 230812B (GCN 34391), we find a previously uncatalogued X-ray
point source in preliminary data from Swiftâ€™s X-ray Telescope.

The preliminary position is RA/Dec (J2000) = 249.13957, 47.854760,
which is equivalent:

RA(J2000) = 16h 36m, 33.4s,
Dec(J2000) = +47d 51m 17.1s,

with an estimate error of 10 arcseconds radius. Please note this position
is based upon preliminary data, reported rapidly to aide follow-up. An
updated position will be reported via GCN ASAP.


GRB_name: GRB230812B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34394
SUBJECT: GRB 230812B: Improved Swift/XRT localization
DATE:    23/08/13 05:19:38 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>

K.L. Page (U. Leicester) reports on behalf of the Swift-XRT team:

We have analysed 1.8 ks of XRT data for GRB 230812B, starting 25.4 ks
after the Fermi trigger (GCN 34391, 34392). The data are entirely in
Photon Counting (PC) mode. The currently best available XRT position is
RA, Dec = 249.1323, 47.8574, which is equivalent to:

RA (J2000):  16 36 31.76
Dec(J2000): +47 51 26.7

with an uncertainty of 3.7 arcsec (radius, 90% confidence).

We note that this is 20 arcsec from the preliminary position given in GCN
34393.

A detailed refined analysis circular will be sent when more data are
available.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230812B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34395
SUBJECT: GRB 230812B: KAIT Optical Afterglow Candidate
DATE:    23/08/13 05:26:37 GMT
FROM:    Weikang Zheng at UC Berkeley <weikang@berkeley.edu>

WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on

behalf of the KAIT GRB team:



The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at

Lick Observatory, responded to GRB 230812B (The Fermi GBM team,

GCN 34386) starting at Aug. 13, 04:42:53 UT. We detected an uncataloged

optical afterglow candidate not shown in SDSS archive at position

of (error ~0.5"):


RA:  16:36:31.52  (J2000)

Dec: +47:51:32.24 (J2000)


This position is about 7.4 arcsec to the improved Swift/XRT

localization (Page et al., GCN 34393), which is slightly outside its

estimate 3.7 arcseconds error radius.  We measure the target is

~18.7 in out clear band image at ~9.75 hours after burst. We can

not estimate the variability at this time, further observations

are encouraged.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34396
SUBJECT: Fermi GRB 230812B: MASTER optical counterpart
DATE:    23/08/13 05:28:50 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>


V.Lipunov (Lomonosov MSU),
D.Svinkin (Ioffe Institute),
A.Kuznetsov, A.Sosnovskiy, N.Tiurina, E.Gorbovskoy, Ya.Kechin, P.Balanutsa, K.Zhirkov,
O.Gress,  A.Chasovnikov, G.Antipov, D.Vlasenko, V.Senik, V.Topolev, Yu.Tselik, Siyu Wu, D.Cheryasov, V.Shumkov, T.Pogrosheva (Lomonosov Moscow State University,SAI,Physics Department),
C.Francile, F. Podesta, C.Lopez, R. Podesta (Observatorio Astronomico Felix Aguilar OAFA),
D.Buckley (SAAO),
R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino
Alvarez,J.Martinez,A.Corella,L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),
N.M.Budnev, O.Gress (ISU,API),
A.Gabovich, V.Yurkov (BSPU),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),

MASTER started Fermi GRB 230812B (Fermi GBM team GCN 34386, Ttrigger=18:58:12,
Lesage et al. GCN 34387, Evans et al. GCN 34388, Scotton  et al. GCN 34387, Roberts et al. GCN 34391)
at MASTER-SAAO (Lipunov et al GCN 34389, see covermap, near horizont; GCN 34390) by MASTER-II and MASTER very wide field cameras (Lipunov et al. 2010)

Fermi GBM error-box was covered by MASTER-SAAO, MASTER-Tavrida (since 2023-08-12 21:56:45 UT), MASTER-OAFA.

There is optical counterpart at
R.A.,Dec.2000= 16 36 31.48 +47 51 35.14
with m=18.2 at several set of images.

that is in ~18" of Swift-XRT preliminary counterpart (Swift GCN 34393)

We observed it till sunrise in MASTER-Tavrida , reduction will be continued.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34397
SUBJECT: GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi  GRB (Trigger 713559497)
DATE:    23/08/13 08:02:28 GMT
FROM:    Anirudh Salgundi <salgundi.anirudh@gmail.com>

Anirudh Salgundi (IITB), Vishwajeet Swain (IITB), Harsh Kumar (IITB), Tomas Ahumada (CIT), Robert Stein (CIT), Igor Andreoni (UMD), Michael Coughlin (UMN), Shreya Anand (CIT), Viraj Karambelkar (CIT), Mansi Kasliwal (CIT), Avery Wold (IPAC), Theophile du Laz (CIT), Simeon Reusch (DESY), Igor Andreoni (UMD),  Eric Bellm (UW), Varun Bhalerao (IITB), Brad Cenko (UMD), Brian Healy (UMN), David Kaplan (UWM), Jannis Necker (DESY), D. Perley (LJMU) report on behalf of the ZTF and GROWTH collaborations:

We observed the localization region of the GRB 230812B (trigger 713559497, GCN 34386) detected by the Gamma-Ray Burst Monitor (GBM) on the Fermi satellite with the 47 square-degree Zwicky Transient Facility (ZTF) camera (Graham et al., 2019; Bellm et al., 2019). We obtained images in the g-, and r- covering 420 square degrees beginning at 2023-08-13 03:34:57 (~8.5 hours after the burst trigger time). This corresponds to ~78% of the probability enclosed in the Earth-occultation corrected GRB localization map. Each exposure was 300 seconds with median depths of 21.9 mag in both g-band and r-band. The images were processed in real-time through the ZTF reduction and image subtraction pipelines at IPAC (Masci et al. 2019).

We queried the ZTF alert stream using Kowalski (Duev et al. 2019) through Fritz (Coughlin et al. 2023). We required at least 2 detections separated by at least 15 minutes to select against moving objects. Furthermore, we cross-match our candidates with the Minor Planet Center to flag known asteroids, reject stellar sources (Tachibana and Miller 2018), and apply machine learning algorithms (Mahabal et al. 2019). We require that no spatially coincident ZTF alerts were issued before the detection time of the GBM trigger. Close to 40 sources were time and spatially coincident with the burst, most of them showing g-r ~ 0 mag and a slow evolution. 


We recover the candidate afterglow reported in Zheng et al. (GCN 34395) and Lipunov et al. (GCN 34396), and we highlight its rapid evolution: r-band decay rate ~2 mag/day. We note that this source is ~6" from the source circulated in Page et al. (GCN 34394) detected by the Neil Gehrels Swift Observatory.

We additionally crossmatched the optical candidates to the Swift sources circulated and in Evans et al (GCN 34388, http://www.swift.ac.uk/xrt_products/TILED_GRB00115) and we find no other coincidences.

The details of the afterglow candidate in the table below: 

ZTF name , AT name , UT first alert , t-t0 (days) , filter , mag (AB) , mag error (AB)
-----------------------------------------------------------------
ZTF23aaxeacr , AT 2023pel , 2023-08-13 03:34:56 , 0.35 , r , 18.85 , 0.04
ZTF23aaxeacr , AT 2023pel , 2023-08-13 04:24:05 , 0.39 , g , 19.19 , 0.02 


We encourage further follow-up.


ZTF and GROWTH are worldwide collaborations comprising Caltech, USA; IPAC, USA, WIS, Israel; OKC, Sweden; JSI/UMd, USA; U Washington, USA; DESY,
Germany; MOST, Taiwan; UW Milwaukee, USA; LANL USA; Tokyo Tech, Japan; IITB, India; IIA, India; LJMU, UK; TTU, USA; SDSU, USA and USyd, Australia.
ZTF acknowledges the generous support of the NSF under AST MSIP Grant No 1440341.
GROWTH acknowledges generous support of the NSF under PIRE Grant No 1545949.
Alert distribution service provided by DIRAC@UW (Patterson et al. 2019).
Alert database searches are done by AMPEL (Nordin et al. 2019) and Kowalski (Duev et al. 2019). The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34398
SUBJECT: GOTO confirmation and possible host galaxy of GRB230812B optical afterglow 
DATE:    23/08/13 08:19:47 GMT
FROM:    ackleyastro@gmail.com

K. Ackley; B. P. Gompertz; B. Godson; S. Belkin; D. O'Neill; A. Levan; T. Killestein; G. Ramsay; D. Malesani; R. Starling; M. J. Dyer; J. Lyman; K. Ulaczyk; F. Jiminez-Ibarra; A. Kumar; D. Steeghs; D. K. Galloway; V. Dhillon; P. O'Brien; K. Noysena; R. Kotak; R. P. Breton; L. K. Nuttall; E. Pall'e and D. Pollacco report on behalf of the GOTO collaboration:

We report on observations with the Gravitational-wave Optical Transient Observer (GOTO; Steeghs et al. 2022) in response to GRB 230812B (Page et al. GCN 34394, Scotton et al. GCN 34392, Lesage et al. GCN 34391). We covered the field of the X-ray (Swift, Page et al. GCN 34394) and optical (KAIT Zheng et al. GCN 34395, MASTER Lipunov et al. GCN 34396) candidate afterglow. The field was observed several times between 21:08:01 UT and 23:37:33 UT on 2023-08-12 (starting 2.16 hours after trigger). Each observation consisted of 4x90s exposures in the GOTO L-band (400-700 nm).

Images were processed immediately after acquisition using the GOTO pipeline. We confirm the optical afterglow as reported by KAIT (Zheng et al. GCN 34395) with the first detection at 2.29 hours. Our observations show a clear decay as the source faded by approximately 0.76 magnitudes over 2.27 hours.

Obs Date | RA(J2000) | Dec(J2000) | Filter | Mag(AB)
2023-08-12 21:15:40 | 249.13 | 47.86 | L | 17.45 +/- 0.02

We note the presence of an underlying extended source at the KAIT localisation in PS1 imaging and deep HyperSuprimeCam imaging, and suggest it to be the host galaxy of GRB 230812B. 

Magnitudes were calibrated using ATLAS-REFCAT2 (Tonry et al. 2018) and are not corrected for Galactic extinction.

Observations are ongoing.

GOTO (https://goto-observatory.org) is a network of telescopes operated at the Roque de los Muchachos Observatory on La Palma, Spain, and Siding Spring Observatory in NSW, Australia, on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory & Planetarium, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT), the University of Turku, the University of Portsmouth, the University of Manchester and the Instituto de Astrofisica de Canarias (IAC).


GRB_name: GRB230812A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34399
SUBJECT: GRB 230812: Swift/UVOT Detection
DATE:    23/08/13 09:01:24 GMT
FROM:    Paul Kuin at MSSL <npkuin@gmail.com>

Paul Kuin (MSSL/UCL) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230812
25418 s after the GBM trigger (Roberts et al., GCN Circ. 34391).
The Fermi LAT also detected the trigger (Scotton et al, GCN Circ. 34392).
An candidate optical counterpart was reported (Zheng & Filippenko, GCN
Circ.
34395; Lipunov et al., GCN Circ 34396; Salgundi et al., GCN Circ. 34397)
near the reported XRT candidate (Kennea, GCN Circ. 34393, Page, GCN Circ.
34394).  A source consistent with the XRT position is detected in the UVOT
exposures.

Preliminary detections using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures
are:

Filter         T_start(s)   T_stop(s)      Exp(s)           Mag

white            25418        31151          390         20.48 +/- 0.18

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.024 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB230812B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34400
SUBJECT: GRB 230812B: Swift-XRT afterglow detection
DATE:    23/08/13 09:01:52 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

A.P. Beardmore (U. Leicester), A. Melandri (INAF-OAR), T. Sbarrato
(INAF-OAB), P. D'Avanzo (INAF-OAB), J.A. Kennea (PSU), A. Tohuvavohu
(U. Toronto), D.N. Burrows (PSU), J.P. Osborne (U. Leicester) and P.A.
Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the
Fermi/GBM-detected burst GRB 230812B in a series of observations tiled
on the sky. The total exposure time is 8.3 ks, distributed over 27
tiles; the maximum exposure at a single sky location was 4.6 ks. The
data were collected between T0+25.4 ks and T0+38.1 ks, and are entirely
in Photon Counting (PC) mode. 

Four uncatalogued X-ray sources are detected, of which one ("Source 7")
is above the RASS 3-sigma upper limit at this position, and is
therefore likely the GRB afterglow. Using 4926 s of PC mode data and 4
UVOT images, we find an enhanced XRT position (using the XRT-UVOT
alignment and matching UVOT field sources to the USNO-B1 catalogue):
RA, Dec = 249.13196, +47.85892 which is equivalent to:

RA (J2000): 16h 36m 31.67s
Dec(J2000): +47d 51' 32.1"

with an uncertainty of 2.1 arcsec (radius, 90% confidence). This
position is 106.5 arcmin from the Fermi/GBM position, but only 6.7
arcmin from the Fermi/LAT position. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.8 (+/-0.4).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.82 (+/-0.15). The
best-fitting absorption column is  9.6 (+4.3, -3.9) x 10^20 cm^-2, in
excess of the Galactic value of 2.0 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.4 x 10^-11 (4.0 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      9.6 (+4.3, -3.9) x 10^20 cm^-2
Galactic foreground: 2.0 x 10^20 cm^-2
Excess significance: 3.2 sigma
Photon index:      1.82 (+/-0.15)

If the light curve continues to decay with a power-law decay index of
1.8, the count rate at T+24 hours will be 0.038 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.3 x
10^-12 (1.5 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021589.
The results of the full analysis of the tiled XRT observations are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00115.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230812B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34401
SUBJECT: GRB 230812B: GECAM-C observation of a very bright burst
DATE:    23/08/13 09:31:23 GMT
FROM:    Dong Xu at NAOC/CAS <dxu@nao.cas.cn>

Shaolin Xiong, Jiacong Liu, Yue Huang report on behalf of the GECAM team:

GECAM-C was triggered in-flight by a very bright burst, GRB 230812B, at 2023-08-12T18:58:12.100 UTC (T0), which was also observed by Fermi/GBM (Fermi GBM Team, GCN 34386), Fermi/LAT (Scotton et al, GCN 34392), etc. Both the GECAM-C in flight location and on-ground location are generally consistent with the Fermi/GBM within error.

According to the realtime alert data, the GECAM-C light curve shows a FRED shape with a duration (T90) of ~4 sec (6-1000 keV). The time-averaged spectrum shows that it could be adequately fit by a Band function with a fluence about 2E-4 erg/cm2 in 20-1000 keV. We note that this analysis is based on realtime alert data and thus very preliminary. Refined analysis will be reported later.

Gravitational wave high-energy Electromagnetic Counterpart All sky Monitor (GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS).


GRB_name: GRB230812B
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34402
SUBJECT: GRB230812B: AGILE/MCAL detection
DATE:    23/08/13 11:45:31 GMT
FROM:    Claudio Casentini at INAF-IAPS <claudio.casentini@inaf.it>

C. Casentini (INAF/IAPS), F. Longo (Univ. Trieste and INFN Trieste), C. Pittori,
F. Verrecchia (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata),
A. Ursi (ASI and INAF/IAPS), A. Argan, M. Cardillo, Y. Evangelista, L. Foffano,
G. Piano (INAF/IAPS), A. Addis, L. Baroncelli, A. Bulgarelli, A. Ciabattoni, A. Di Piano,
V. Fioretti, G. Panebianco, N. Parmiggiani (INAF/OAS-Bologna), F. Lucarelli
(SSDC, and INAF/OAR), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia,
A. Trois (INAF/OA-Cagliari), I. Donnarumma, E. Menegoni (ASI), A. Giuliani (INAF/IASF-Mi),
P. W. Cattaneo (INFN Pavia), F. Cutrona (Univ. Milano Bicocca) and P. Tempesta
(TeleSpazio) report on behalf of the AGILE Team:

The AGILE satellite detected the GRB 230812B at T0 = 2023-08-12 18:58:12 s (UTC),
reported by Fermi (GCNs #34386, #34387, #34391, #34392), Swift (GCNs #34388, #34393,
#34394, #34395, #34399, #34400) and MASTER (GCNs #34389, #34396).

The event lasted about 8 s and it released a total number of 17046 counts in the MCAL
detector (above a background rate of 590 Hz) and 97310 counts in the AC-Top detector
(above a background rate of 3188 Hz). The AGILE ratemeters light curves can be found
at http://www.agilescienceapp.it/notices/GRB230812B_AGILE_RM_ND.png .

The event also triggered a high time resolution MCAL data acquisition,
from T0 s to T0+2 s (UTC), and released 12643 counts in the detector, above
a background rate of 561 Hz. The MCAL light curve can be found
at http://www.agilescienceapp.it/notices/GRB230812B_084865_618951492.000000.png .

At the T0, the event was 55 deg off-axis.

Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices
can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html


GRB_name: GRB230812B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34403
SUBJECT: Konus-Wind detection of GRB 230812B
DATE:    23/08/13 12:39:29 GMT
FROM:    Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>

D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long very bright GRB 230812B (Fermi GBM detection:
Lessage et al., GCN 34387; Roberts et al., GCN 34391;
Fermi LAT detection: Scotton et al., GCN 34392;
GECAM-C observation: Xiong et al., GCN 34401;
AGILE/MCAL detection: Casentini et al., GCN 34402)
triggered Konus-Wind (KW) at T0=68292.611 s UT (18:58:12.611).

The burst light curve shows a single smooth emission pulse,
which starts at ~T0-0.1 s, peaks at ~T0+0.7 s,
and has a total duration of ~20 s.
The emission is seen up to ~5 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB230812_T68292/

As observed by Konus-Wind, the burst had
a fluence of (3.27 Â± 0.07)x10^-4 erg/cm^2 and
a 64-ms peak energy flux, measured from T0 + 0.704 s,
of (2.63 Â± 0.11)x10^-4 erg/cm^2/s (both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+19.712 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.85 (-0.03,+0.03),
the high energy photon index beta = -2.38 (-0.05,+0.04),
the peak energy Ep = 288 (-12,+12) keV,
chi2 = 169/97 dof.

The spectrum near the peak count rate (measured from T0+0.512 to T0+0.768 s)
is best fit in the 20 keV - 15 MeV range
by a GRB (Band) function with the following model parameters:
the low-energy photon index alpha = -0.17 (-0.08,+0.09),
the high energy photon index beta = -2.65 (-0.14,+0.11),
the peak energy Ep = 444 (-30,+31) keV,
chi2 = 68/56 dof.

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34404
SUBJECT: GRB 230812B: GMG - GRANDMA observations
DATE:    23/08/13 14:40:05 GMT
FROM:    Jirong Mao at Yunnan Obs <jirongmao@mail.ynao.ac.cn>

J. Mao, K.-X. Lu, J.-M. Bai (YNAO), S. Karpov (FZU), M. C. Coughlin (UMN), A. Ugarte Postigo, S. Antier (OCA), O. Pyhsna (Univ. KieV), Z. Vidadi (Shao) on behalf of the Yunnan observatories team and the GRANDMA team:

We observed the field of GRB 230812B (Lesage et al. GCN 34387; Scotton et al. GCN 34392; Page GCN 34394; Zheng & Filippenko GCN 34395; Lipunov et al. GCN 34396; Salgundi et al. GCN 34397; Ackley et al. GCN 34398; Xiong et al. GCN 34401; Casentini et al. 34002; Frederiks et al. 34404) by the GMG telescope in Yunnan observatories. The observation began from UT 13:34:22 August 13, 2023, about 18.5 hours from the trigger. We clearly observed the optical afterglow of R~19.9+/-0.1. The further observation is ongoing.


GRB_name: GRB230812B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34405
SUBJECT: GRB 230812B: Detected Optical Afterglow Candidate
DATE:    23/08/13 17:32:55 GMT
FROM:    Mohammad Odeh at Al Khatim Observatory M44 <mshodeh@gmail.com>

Mohammad Odeh, Osama Ghannam, Anas Mohammad, Khalfan Al-Noaimy, and Sameh
Al-Ashi, report on behalf of Al-Khatim Observatory (AKO) operated by the
International Astronomical Center in Abu Dhabi, UAE:



We observed the field of GRB 230812B (Lesage et al., GCN 34387; Scotton et
al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN 34395; Lipunov et
al., GCN 34396; Salgundi et al., GCN 34397; Ackley et al., GCN 34398; Xiong
et al., GCN 34401; Casentini et al., GCN 34002; Frederiks et al., GCN
34403; Mao et al., GCN 34404), with our 0.36m f/7.7 robotic telescope. The
observation was done on 13 August 2023 from 16:15 to 16:47 (UT), about 21.6
hours from the trigger.



We obtained multiple 180-sec exposures in Ic filter. We detected an optical
afterglow candidate at:

R.A. (J2000): 16:36:31.45

Dec. (J2000): +47:51:32.3



That is the same localization of (Zheng & Filippenko, GCN 34395), which is
about 5.5 arcsec from the improved Swift/XRT localization (Page, GCN 34394).



The following observation was calculated using Atlas catalogue as a
reference:

-----------------------------------------------------------------------------

ObsTime (mid), Exposure (sec), Filter, Mag

-----------------------------------------------------------------------------

2023-08-13T16:32:40Z, 10 x 180s (stacked), Ic, 18.8 +/- 0.21

-----------------------------------------------------------------------------



The magnitude is not corrected for galactic extinction.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34406
SUBJECT: GRB 230812B: SAO RAS optical observations
DATE:    23/08/13 22:20:02 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin and O. I. Spiridonova (SAO RAS), report on behalf of
the GRB follow-up team.

We observed the field of GRB 230812B (Lesage et al., GCN 34387;
Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN
34395; Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley
et al., GCN 34398; Xiong et al., GCN 34401; Casentini et al., GCN
34002; Frederiks et al., GCN 34403; Mao et al., GCN 34404; Odeh et
al., GCN 34405) with the 1-m telescope of SAO RAS Zeiss-1000 equipped
with the CCD photometer. We obtained 3 x 300 sec. images in Rc band on
August 13, 20:14:15--20:31:46 UT under mediocre weather conditions.

The OT is clearly detected in our stacked frame with the brightness of
R = 20.45 +/- 0.07 (t_mid - t0 = 1.0589 days).

This preliminary photometry is based on the nearby SDSS stars;
magnitudes are converted using Lupton (2005) equations.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34408
SUBJECT: GRB 230812B: Montarrenti Observatory optical observations
DATE:    23/08/14 00:58:33 GMT
FROM:    Simone Leonini at Montarrenti Observatory (Siena, Italy) <s.leonini@iol.it>

S. Leonini, M. Conti, P. Rosi, L.M. Tinjaca Ramirez (Montarrenti Observatory, Siena, Italy) report:

We observed the field of GRB 230812B (Lesage et al., GCN 34387; Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN 34395; Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley et al., GCN 34398; Xiong et al., GCN 34401; Casentini et al., GCN 34002; Frederiks et al., GCN 34403; Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin et al., GCN 34406) with the automatic 0.53m Ritchey-Chretien telescope at Montarrenti Observatory (Siena, Italy, IAU code C88).

The observations were started under good weather conditions at 2023-08-13 19:20:53 UT (approximately 24 hours after burst) stacking 50x30s R and I-band CCD images.

The OT was clearly detected at the following position:

RA      (J2000)  16h 36m 31.47s +/-0.11 
Decl. (J2000) +47Â° 51' 32.7"      +/-0.14

Preliminary photometry is obtained using nearby PanSTARRS stars as follows: 

MJD                  Filter   Mag.      Err.
60170.32784    R       20.48  +/-0.07
60170.32827    I        19.78  +/-0.10

Magnitudes are converted using Lupton (2005) equations and are not corrected for galactic dust extinction.


GRB_name: GRB230812B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34409
SUBJECT: GRB 230812B: Redshift from OSIRIS+/GTC
DATE:    23/08/14 01:49:35 GMT
FROM:    Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>

A. de Ugarte Postigo (OCA-CNRS), J.F. Agui Fernandez (IAA-CSIC), C. C Thoene (ASU-CAS) and  L. Izzo (INAF-OACN and DARK/NBI) report:

We have observed the afterglow of GRB 230812B (Roberts et al. GCN34391, Scotton et al. GCN 34392, Zheng & Filippenko GCN 34395, Beardmore et al. GCN 34400) with OSIRIS+ mounted on the 10.4m GTC telescope at Roque de los Muchachos Observatory in La Palma (Spain). The observation consisted of spectroscopy with an exposure time of 3x900s and grism R1000B, with a wavelength coverage between 3600 and 7800 AA. The first spectrum started at 21:37 UT, 1.110 days after the burst.

In a preliminary reduction using old calibrations, the spectrum shows a strong trace with both emission and absorption lines which we identify as MgII, MgI, CaII, CaI in absorption, and [OII] and [OIII] in emission, at a common redshift of 0.360, which we interpret as the redshift of the GRB.

At this redshift, and assuming a fluence of 3.27e-4 erg/cm^2 as reported by Fermi/GBM (Roberts et al. GCN34391), the burst would have an Eiso = 8.3e52 erg. Together with a Ep = 273 keV (Roberts et al. GCN34391), GRB 230812B is consistent with the Amati relation for long GRBs.

We acknowledge excellent support from the GTC staff.


GRB_name: GRB230812B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34410
SUBJECT: GRB 230812B: Spectroscopy from NOT
DATE:    23/08/14 01:51:16 GMT
FROM:    Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>

A. de Ugarte Postigo (OCA-CNRS), L. Izzo (INAF-OACN and DARK/NBI), D.B. Malesani (Radboud and DAWN/NBI), K. Matilainen (NOT) report:

We have observed the afterglow of GRB 230812B (Roberts et al. GCN34391, Scotton et al. GCN 34392, Zheng & Filippenko GCN 34395, Beardmore et al. GCN 34400) with AlFOSC, mounted on the 2.5m NOT telescope at Roque de los Muchachos Observatory in La Palma (Spain). 
We have performed spectroscopy with an exposure of 3x1200s and grism #4, with a spectral coverage between 3500 and 9600 AA. The observation started at 22:14 UT, 1.136 days after the trigger.

The spectrum shows a trace throughout the complete spectral range. In a preliminary reduction we donâ€™t identify clear absorption features, but we do see weak detections of [OII], [OIII] and H-alpha at a redshift of z=0.360, as reported by de Ugarte Postigo et al. (GCN34409).


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34412
SUBJECT: GRB 230812B: AbAO optical observations
DATE:    23/08/14 08:02:51 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

S. Belkin (IKI),  R. Ya. Inasaridze (AbAO),  A. Pozanenko (IKI), N. 
Pankov (HSE, IKI) report on behalf of GRB IKI FuN:

We observed the field of GRB 230812B (Fermi GBM Team, GCN 34386; Scotton et al., GCN 34392; Page et al. GCN 34394; Kuin et al., GCN 34399; Casentini et al., GCN 34402) with AS-32 telescope of Abastumani observatory (AbAO) in R-filter starting on Aug. 13 (UT) 17:32:00. We  detected the  afterglow (Lesage et al., GCN 34387; Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN 34395; Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley et al., GCN 34398; Xiong et al., GCN 34401; Casentini et al., GCN 34402; Frederiks et al., GCN 34403; Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin et al., GCN 34406; Leonini et al., GCN 34408; de Ugarte Postigo et al., GCNs 24409, 34410) in the stacked image. Preliminary photometry of the object is following

Date       UT start   t-T0    Filter Exp.    OT    Err.  UL(3sigma)
                       (mid, days)    (s)

2023-08-13 17:32:00   0.97336  R     54*60  20.35 0.24    20.9

The photometry is based on nearby SDSS stars used in (Moskvitin et al, GCN 34406):
RA DEC R (Lupton transformations)
16:36:35.9365104 +47:52:54.574320 14.893 0.008
16:36:32.6835360 +47:53:44.537784 16.531 0.009
16:36:25.6055880 +47:53:20.456304 16.827 0.009
16:36:25.1691816 +47:52:20.931816 16.068 0.008
16:36:44.6580984 +47:50:56.806944 15.785 0.008
16:36:40.1374488 +47:54:02.128752 15.698 0.008

The underlying extended source galaxy mentioned by GOTO (Ackley et al., GCN 34398) is visible in Legacy Survey DR10 Catalog with r~22.66 and classified as round exponential galaxy.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34413
SUBJECT: GRB 230812B: OASDG optical observations
DATE:    23/08/14 10:47:40 GMT
FROM:    luca.izzo@inaf.it

N. Ruocco, A. Catapano (OASDG) and L. Izzo (INAF-OACN & DARK/NBI) report:  

We observed the field of GRB 230812B (Lesage et al. GCN 34387, Roberts et al. GCN 34391, Scotton et al. GCN 34392, Beardmore et al. GCN 34400, Xiong et al. GCN 34401, Casentini et al. GCN 34402, Frederiks et al. GCN 34403) with the 0.5m telescope of the Osservatorio Astronomico S. Di Giacomo located in Agerola, Italy ( https://osservatorio.astrocampania.it/ - MPC L07). We obtained multiple 300s images in the Rc filter under good weather conditions, with the first observation starting at MJD 60169.818 (1.027 days after the GRB detection). 

In the final stacked image, we detect a faint source at the enhanced position reported by Swift-XRT (Beardmore et al. GCN 34400) and by optical telescopes (Zheng & Filippenko, GCN 34395, Lipunov et al., GCN 34396, Salgundi et al., GCN 34397, Ackley et al., GCN 34398, Kuin et al. GCN 34399, Mao et al., GCN 34404, Odeh et al., GCN 34405, Moskvitin et al., GCN 34406, Leonini et al., GCN 34408, de Ugarte Postigo et al. GCN 34409 & 34410, Belkin et al., GCN 34412). We measure a magnitude for the GRB afterglow of Rc(AB) = 20.51 +/- 0.16 mag. The calibration was performed using nearby stars in the Pan-STARRS PS1 catalog, and using transformation equations to Rc magnitudes. Further analyses are ongoing.


GRB_name: GRB230812B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34414
SUBJECT: GRB 230812B: rest-frame energetics from Konus-Wind observation
DATE:    23/08/14 13:26:42 GMT
FROM:    Dmitry Frederiks at Ioffe Institute <fred@mail.ioffe.ru>

D. Frederiks, A.Lysenko, A. Ridnaia, D. Svinkin,
A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

Assuming the spectrum and the observer-frame energetics of the very bright
GRB 230812B measured by KW (GCN 34403); the source redshift z=0.360
(de Ugarte Postigo et al., GCNs 34409, 34410); and a standard cosmology
with H_0 = 67.3 km/s/Mpc, Omega_M = 0.315, and Omega_Lambda = 0.685 (Planck Collaboration, 2014);
we estimate the burst isotropic energy release E_iso to (1.09 Â± 0.02)x10^53 erg,
the isotropic peak luminosity L_iso to (1.25 Â± 0.05)x10^53 erg/s,
the rest-frame peak energy of the time-integrated spectrum Ep,i,z to (392 Â± 16) keV,
and the rest-frame peak energy at the peak of the emission Ep,p,z to (604 Â± 41) keV.

With the obtained estimates, GRB 220627A fits perfectly both 'Amati' and 'Yonetoku'
relations derived for the sample of >300 long KW GRBs with known redshifts
(Tsvetkova et al., 2017; Tsvetkova et al., 2021), see
http://www.ioffe.ru/LEA/GRBs/GRB230812_T68292/GRB230812B_rest_frame.pdf
This suggests that an energy reservoir powering the burst and its emission mechanism
are similar to that typical of long-duration GRBs.

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34415
SUBJECT: GRB 230812B: Osservatorio Astronomico "Nastro Verde" optical observation
DATE:    23/08/14 13:45:40 GMT
FROM:    Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 <osservatorionastroverde@gmail.com>

Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report: 

We observed the field of GRB 230812B (Lesage et al. GCN 34387, Roberts et al. GCN 34391, Scotton et al. GCN 34392, Beardmore et al. GCN 34400, Xiong et al. GCN 34401, Casentini et al. GCN 34402, Frederiks et al. GCN 34403)
with telescope of Nastro Verde Observatory - Sorrento (Naples), Italy.
Member of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
AstroCampania Associazione

The observations started at 19:40 UT of 2023/08/13, after about 24 hours after the GRB trigger, at the end of twilight with clear skies, with principal telescope  SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME
I took 22 image of 240 sec each. All images are unfiltered, calibrated with masterdark and masterflat, stacked with Tycho Tracker and Astrometrica software
We have detected a clearly visible source at the enhanced position reported by Swift-XRT (Beardmore et al. GCN 34400) and by optical telescopes (Zheng & Filippenko, GCN 34395, Lipunov et al., GCN 34396, Salgundi et al., GCN 34397, Ackley et al., GCN 34398, Kuin et al. GCN 34399, Mao et al., GCN 34404, Odeh et al., GCN 34405, Moskvitin et al., GCN 34406, Leonini et al., GCN 34408, de Ugarte Postigo et al. GCN 34409 & 34410, Belkin et al., GCN 34412, Ruocco et al. GCN 34413)
at following position

RA      (J2000)  16h 36m 31.47s 
Decl.   (J2000) +47Â° 51' 32.2"      

Preliminary photometry summing three sets of 7 images of 240 sec each, using Astrometrica and the UCAC4 catalog is as follows

2023 08 13.83014 16 36 31.46 +47 51 32.7          19.8 R      
2023 08 13.85209 16 36 31.52 +47 51 32.1          19.8 R      
2023 08 13.87403 16 36 31.47 +47 51 32.3          20.2 R      



Magnitudes were estimated with the UCAC4 cat. and 
are not corrected for galactic dust extinction.



The message may be cited.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34416
SUBJECT: GRB 230812B: Faulkes Telescope North optical afterglow follow-up 
DATE:    23/08/14 14:17:45 GMT
FROM:    Manisha Shrestha at University of Arizona <mshrestha1@arizona.edu>

M. Shrestha (Univ. of Arizona), D. Sand (Univ. of Arizona), K. D. Alexander (Univ. of Arizona), J. Andrews (Gemini), K. Bostroem (Univ. of Arizona),  J. Pearson (Univ. of Arizona), G. Hosseinzadeh (Univ. of Arizona), N. Smith (Univ. of Arizona), D. A. Howell (LCO/UCSB), C. McCully (LCO/UCSB), M. Newsome (LCO/UCSB), E Padilla Gonzalez (LCO/UCSB), C. Pellegrino (LCO/UCSB), G. Terreran (LCO/UCSB), J. Farah (LCO/UCSB) report on behalf of a wider Global Supernova Project collaboration:
 
We observed the field of Swift GRB 230812B (Fermi GBM GCN 34386) with Faulkes Telescope North, on 2023-08-14 at 5:50:39 UT (60170.2435 MJD, ~1.45 days after the trigger) using the MuSCAT3 imager in the g,r, and i bands.  Data were calibrated with respect to nearby SDSS sources.
 
We clearly detect the optical counterpart in the g,r, and i bands. The magnitudes are as follows: 
g = 21.38 +- 0.07
r  = 20.81 +- 0.04
i  = 20.71 +- 0.07

These values are not corrected for galactic extinction.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34417
SUBJECT: GRB 230812B: Bassano Bresciano Observatory optical observations
DATE:    23/08/14 14:26:48 GMT
FROM:    Ulisse Quadri at Bassano Bresciano Obs <oabb@ulisse.bs.it>

U.Quadri and  L.Strabla (Bassano Bresciano Astronomical Observatory),
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report: 

We imaged the field of GRB 230812B (Lesage et al., GCN 34387; 
Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN 34395; 
Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley et al., GCN 34398; 
Xiong et al., GCN 34401; Casentini et al., GCN 34002; Frederiks et al., GCN 34403; 
Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin et al., GCN 34406)
detected by FERMI(trigger 713559497.049606 / 230812790)
with the robotic telescope of (IAU station 565) Bassano Bresciano 
Observatory, Italy. Member of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili-GRB.
GAC - Gruppo Astrofili Cremonesi.

The observations started 24.57 hour after the FERMI trigger, At the end of twilight 
with our Newton telescope D=250 mm F/D=4.8

Weather conditions were good.

We co-added 2 series of 70 exposures of 60 sec each.

Start T0+      End T0+     
24.57 hour     27.09 hour

We detected a (fading) afterglow in the error box of the XRTcandidate.
at the following position (+/- 2 arcsec):

RA (J2000) =  16h 36m 31.51s
DEC(J2000) = +47d 51p 32.2s

The results of our photometry are:

-----------------------------------
      JD         Mag    Err    Flt   
-----------------------------------
2460170.36459   19.9 +/- 0.2    CR    
2460170.38708   20.1 +/- 0.2    CR    

CR is unfiltered with R zero point.

Magnitudes were estimated with the PanSTARRS cat. and 
are not corrected for galactic dust extinction.

Reference:
http://www.osservatoriobassano.org/GRB.asp

The message may be cited.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34418
SUBJECT: GRB 230812B : optical observations from Observatoire de Haute-Provence
DATE:    23/08/14 15:16:09 GMT
FROM:    Emeric Le Floc'h at CEA-Saclay <emeric.lefloch@cea.fr>

C. Adami (LAM), T. Adami (ENS Paris-Saclay), B. Schneider (MIT), A. Saccardi (GEPI, Obs. de Paris), A. de Ugarte Postigo (OCA, CNRS), E. Le Flocâ€™h, F. SchÃ¼ssler, D. Turpin (CEA-Saclay), S. D. Vergani, J. P. Palmerio (GEPI, Obs. de Paris), S. Basa (LAM), D. GÃ¶tz (CEA-Saclay), S. Antier (OCA) report, on behalf of a larger collaboration:

We observed the field of GRB 230812B (Fermi GBM Team GCN, 34386; Roberts et al., GCN 34391; Scotton et al., GCN 34392; Page et al., GCN 34394; Zheng & Filippenko, GCN 34395; Kuin et al., GCN 34399; Beardmore et al., GCN 34400; Casentini et al., GCN 34402; de Ugarte Postigo et al., GCN 24409, 34410) using the T120 telescope of Observatoire de Haute Provence (OHP) in imaging mode. We obtained 10x360s exposures in the V-band with a mid-epoch of 2023-08-13 22:00 UT (~1 day after trigger), 2x300s exposures in the R-band with a mid-epoch of 2023-08-14 00:00 UT, and 10x360s exposures in the I band with a mid-epoch of 2023-08-13 20:40 UT.
We derive the following photometry, calibrated against the Pan-STARRS catalog and not corrected for Galactic dust reddening:

V = 20.87 +/- 0.08 mag
R = 20.64 +/- 0.09 mag
I = 19.77 +/- 0.04 mag

We also observed the field of GRB 230812B using the T193cm equipped with the MISTRAL spectro-imager. We obtained 4x300s + 1x60s exposures in the râ€™ band at a mid-epoch of 2023-08-13 20:15 UT, leading to the following preliminary photometry estimate:

râ€™ = 20.32 +/- 0.06 mag

We finally obtained 1h of exposure (2x15min + 1x30min) in spectroscopic mode, using the blue setting of MISTRAL. We clearly detect the continuum associated with the transient emission, leading to a redshift upper limit (z<2.5) consistent with the redshift determination obtained by the GTC and the NOT (de Ugarte Postigo et al., GCN 24409, 34410). The signal to noise in the final combined spectrum is however not sufficient to securely identify any absorption line.

We acknowledge Claire Moutou as well as the excellent support from Jean Balcaen and Yoann Degot-Longhi (Observatoire de Haute Provence).


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34419
SUBJECT: GRB 230812B: Leavitt Observatory optical observations
DATE:    23/08/14 16:37:57 GMT
FROM:    leavittob@gmail.com

L. Moretti and E. Pavoni (Leavitt Observatory), in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (UniversitÃ  degli Studi Di Salerno)
report: 

We observed the field of GRB 230812B (Fermi GBM Team GCN, 34386; Roberts et al., GCN 34391; Scotton et al., GCN 34392; Page et al., GCN 34394; Zheng & Filippenko, GCN 34395; Kuin et al., GCN 34399; Beardmore et al., GCN 34400; Casentini et al., GCN 34402; de Ugarte Postigo et al., GCN 34409, 34410) with the telescope of Leavitt Observatory, Italy. Member of: 

UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili, GRB section.
ATA - Associazione Tuscolana di Astronomia.

The observations began at 20:35 UT on 2023/08/13 (~1 day after the FERMI trigger), at the end of twilight, with our RC telescope D=250 mm F/D=8.

Weather conditions were good.

We took 9 images of 240 sec each. All images are unfiltered, calibrated with master dark and master flat, stacked with ASTAP software.

We detected the afterglow at the following position:
RA(J2000)  = 16h 36m 31.48s
Dec(J2000) = +47Â° 51' 32.1"

We measured its brightness of 20.78 +/- 0.2 mag in our coadd image in clear band, at a mid-time of 25.913 hours after the FERMI trigger, JD 2460170.36944. 

Magnitudes were estimated with the Gaia (BP) DR3 cat. and are not corrected for galactic dust extinction.

The message may be cited.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34420
SUBJECT: GRB 230812B: GIT optical follow-up
DATE:    23/08/14 18:22:14 GMT
FROM:    Vishwajeet Swain at IIT Bombay <vishwajeet.s@iitb.ac.in>

R. Kumar (IITB), A. Salgundi (IITB), V. Swain (IITB), H. Kumar (IITB), V. Bhalerao (IITB), G.C. Anupama (IIA), S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:

We observed the field of the GRB230812B (Fermi GBM Team, GCN 34386) with 0.7m GROWTH-India Telescope (GIT). We started the observation from 14:46:44 UT on 2023-08-13, roughly 20 hours after the Fermi trigger. We obtained multiple frames of 300 sec each in the g' and r' bands. We detected the afterglow in our stacked images at the enhanced Swift XRT localization (Beardmore et al. GCN 34400). The details of the photometry are given in the below table:

----------------------------------------------------------------------

JD (mid) | t-t0 (days)| Filter | Exposure (s) | Magnitude (AB) |

----------------------------------------------------------------------

2460170.139773 | 0.85 | g' | 5 x 300 | 20.34 +/- 0.06 |
2460170.121745 | 0.83 | r' | 4 x 300 | 19.98 +/- 0.05 | 


----------------------------------------------------------------------

Our photometry values are consistent with the results submitted by other optical telescopes (Zheng & Filippenko, GCN 34395, Lipunov et al., GCN 34396, Salgundi et al., GCN 34397, Ackley et al., GCN 34398, Kuin et al. GCN 34399, Mao et al., GCN 34404, Odeh et al., GCN 34405, Moskvitin et al., GCN 34406, Leonini et al., GCN 34408, de Ugarte Postigo et al. GCN 34409 & 34410, Belkin et al., GCN 34412, and N. Ruocco et al., GCN 34413, N. Ruocco et al., GCN 34413, M. Shrestha et al., GCN 34416, C. Adami et al., GCN 34418, L. Moretti et al., GCN 34419).
We confirm that the candidate is decaying fast.

The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34421
SUBJECT: GRB 230812B: Koshka Zeiss-1000 optical observations
DATE:    23/08/14 18:43:43 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

S. Belkin (IKI), I. Nikolenko (INASAN), N. Pankov (HSE, IKI), A. Pozanenko (IKI)  report on behalf of GRB IKI FuN:

We observed the field of GRB 230812B (Fermi GBM Team, GCN 34386; Scotton et al., GCN 34392; Page et al. GCN 34394; Kuin et al., GCN 34399; Casentini et al., GCN 34402) with  Zeiss-1000 telescope of Koshka observatory in R-filter. We  detected the afterglow (e.g. Lesage et al., GCN 34387; Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN 34395; Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley et al., GCN 34398; Xiong et al., GCN 34401; Casentini et al., GCN 34402; Frederiks et al., GCN 34403; Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin et al., GCN 34406; Leonini et al., GCN 34408; de Ugarte Postigo et al., GCNs 24409, 34410; Belkin et al., GCN 34412) in a stacked image. Preliminary photometry of the object is following

Date       UT start   t-T0    Filter Exp.    OT    Err.  UL(3sigma) Telescope
                       (mid, days)    (s)

2023-08-13 18:07:14   0.99724  R    35*120 20.18 0.07    22.0 Zeiss-1000
 
The photometry is based on nearby SDSS stars used in (Moskvitin et al, GCN 34406):
RA DEC R (Lupton transformations)
16:36:35.9365104 +47:52:54.574320 14.893 0.008
16:36:32.6835360 +47:53:44.537784 16.531 0.009
16:36:25.6055880 +47:53:20.456304 16.827 0.009
16:36:25.1691816 +47:52:20.931816 16.068 0.008
16:36:44.6580984 +47:50:56.806944 15.785 0.008
16:36:40.1374488 +47:54:02.128752 15.698 0.008


GRB_name: GRB230814A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34422
SUBJECT: GRB 230814A: Fermi GBM Final Real-time Localization
DATE:    23/08/14 19:05:27 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 18:54:56 UT on 14 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230814A (trigger 713732101.037422 / 230814788).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 288.8, Dec = -14.2 (J2000 degrees, equivalent to J2000 19h 15m, -14d 11'), with a statistical uncertainty of 4.0 degrees.

The angle from the Fermi LAT boresight is 100.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230814788/quicklook/glg_skymap_all_bn230814788.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230814788/quicklook/glg_healpix_all_bn230814788.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230814788/quicklook/glg_lc_medres34_bn230814788.gif


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34423
SUBJECT: GRB 230812B: CrAO ZTSh optical observations
DATE:    23/08/14 19:08:13 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

S. Belkin (IKI), V. Rumyantsev (CrAO), N. Pankov (HSE, IKI),  A. Pozanenko (IKI) report on behalf of GRB IKI FuN:

We observed the field of GRB 230812B (Fermi GBM Team, GCN 34386; Scotton et al., GCN 34392; Page et al. GCN 34394; Kuin et al., GCN 34399; Casentini et al., GCN 34402; Frederiks et al., GCN 34403) with ZTSH 2.6m telescope of CrAO observatory in R-filter. We  detected the  afterglow (e.g. Lesage et al., GCN 34387; Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN 34395; Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley et al., GCN 34398; Xiong et al., GCN 34401; Casentini et al., GCN 34402; Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin et al., GCN 34406; Leonini et al., GCN 34408; de Ugarte Postigo et al., GCNs 24409, 34410; Belkin et al., GCN 34412, 34421) in a stacked image. Preliminary photometry of the object is following

Date       UT start   t-T0    Filter Exp.   OT    Err.  UL(3sigma)  
                      (mid, days)    (s)

2023-08-13 19:24:53   1.03829  R     39*120 20.25 0.05  23.3  

The photometry is based on nearby SDSS stars used in (Moskvitin et al, GCN 34406):
RA DEC R (Lupton transformations)
16:36:35.9365104 +47:52:54.574320 14.893 0.008
16:36:32.6835360 +47:53:44.537784 16.531 0.009
16:36:25.6055880 +47:53:20.456304 16.827 0.009
16:36:25.1691816 +47:52:20.931816 16.068 0.008
16:36:44.6580984 +47:50:56.806944 15.785 0.008
16:36:40.1374488 +47:54:02.128752 15.698 0.008


GRB_name: GRB230814A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34424
SUBJECT: GRB 230814A: BALROG localization (Fermi Trigger 713732101 / GRB 230814788)
DATE:    23/08/14 19:28:45 GMT
FROM:    Jochen Greiner at MPE <jcgrog@mpe.mpg.de>

B. Biltzinger, T. Preis, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
713732101 at 18:54:56 on 14 Aug. 2023 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 288.4+/-1.2 deg
Decl.(2000.0) = -12.0+/-1.3 deg
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB230814788/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB230814788/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB230814788/json

                        


GRB_name: GRB230812B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34425
SUBJECT: GRB 230812B: GRANDMA further observations of ZTF23aaxeacr candidate afterglow
DATE:    23/08/14 21:28:38 GMT
FROM:    Aleksandra Pyshna at Astronomical Observatory of Taras Shevchenko National University of Kyiv, Kyiv, Ukraine <pyshnaya.sasha@gmail.com>

O. Pyshna (AO TSNU of Kyiv), Z. Vidadi (ShAO), S. Beradze (AbAO), Y.Rajabov (UBAI), D. Aql (American Uni. SHJ), S. Antier (OCA), M. Coughlin (UMN), J. Peloton,  P. Hello (IJCLAB), S. Karpov, M. Prouza, M. MaÅ¡ek, M. Blazek (FZU), A. Klotz (IRAP),T. Pradier (Univ. Strasbourg), I. Tosta e Melo (UNICT), D. Turpin (CEA), A. Takey, E. G. Elhosseiny, A. Abulwfa, M. A. El-Sadek, M. Molham (NRIAG), R. Inasaridze, R. Natsvlishvili, N. Kochiashvili, V. Aivazyan (AbAO), A. Baransky, Y. Romanyuk, O. Sokoliuk, A. Simon, V. Vasylenko (Lisnyky) report on behalf of the GRANDMA collaboration:

GRANDMA observed the field of GRB 230812B (Lesage et al. GCN 34387; Scotton et al. GCN 34392; Page GCN 34394; Zheng
& Filippenko GCN 34395; Lipunov et al. GCN 34396; Ackley et al. GCN 34398; Xiong et al. GCN 34401; Casentini et al. 34402; Frederiks et al. 34403; Mao et al. 34404; Odeh et al. 34405; Moskvitin & Spiridonova 34406; Leonini et al. 34408; de Ugarte Postigo et al. 34409; de Ugarte Postigo et al. 34410; Belkin et al. 34412; Ruocco et al. 34413; Frederiks et al. 34414; Ruocco et al. 34415; Shrestha et al. 34416; Quadri et al. 34417; Adami et al. 34418; Moretti et al. 34419; Kumar et al. 34420; Belkin et al. 34421) 
in particular ZTF23aaxeacr candidate afterglow (16:36:31.483 +47:51:32.26) (Salgundi et al. GCN 34397) 


The first observation began about 22.56 hours from the trigger.


As time reference (T0), we choose: 2023-08-12T18:58:12 (60168.79041667 MJD) (Fermi GBM Team 34386)

In the following table we report a subset of the preliminary photometry
of our observations. Magnitudes and upper limits are reported
in the AB system.

ZTF23aaxeacr:

T-T0 (day) |MJD   |Obser.   |Exposure| Filter | Mag +/- err  |Upp.Lim. (AB)
--------------------------------------------------------------------------
0.940|60169.73055556    |Abastumani-T70|46X60s |sdssr|20.35+/-0.12|21.3 (5sig)
0.959|60169.75012731    |      KAO                   |10X180s|sdssg|20.53+/-0.05|21.7 (5sig)
0.988|60169.77848380    |      KAO                   |10X180s|sdssr|20.23+/-0.05|21.5 (5sig)
1.021|60169.81137731    |      KAO                   |20X150s|sdssi|20.17+/-0.03|22.3 (5sig)
1.115|60169.90562500    |  FRAM-CTA-N      |50X60s |  R  |      -     |>19.1 (Vega)


KAO data has been calibrated with respect to the PS1 catalog.
Abastumani-T70 data has been calibrated with respect to the PS1 catalog, with the Johnson cousin conversion into sloan r.
FRAM-CTA-N data has been calibrated with respect to the APASS catalog.

GRANDMA is a worldwide coordinated telescope network
(grandma.ijclab.in2p3.fr)  devoted to the observation of transients
in the context of multi-messenger astrophysics (Antier et al. 2020 MNRAS
497, 5518). Kilonova-Catcher (KNC) is the citizen science program of
GRANDMA (http://kilonovacatcher.in2p3.fr/).


GRB_name: GRB230812B
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34427
SUBJECT: GRB 230812B: Upper limits from a neutrino search with IceCube
DATE:    23/08/14 22:45:46 GMT
FROM:    Jessie Thwaites at IceCube/U Wisc-Madison <thwaites@wisc.edu>

The IceCube Collaboration (http://icecube.wisc.edu/) reports:

IceCube has performed a search for track-like muon neutrino events arriving from the direction of GRB 230812B (GCN Circular 34391 (Fermi-GBM), 34392 (Fermi-LAT)) at the position determined by Swift-XRT (GCN Circular 34394) in a time range of -1 hour/+2 hours from the initial trigger reported by Fermi-GBM (T0=2023-08-12 18:58:12.05 UTC) during which IceCube was collecting good quality data. 

Zero track-like events are found to coincide with the position of the GRB. We accordingly derive a time-integrated muon-neutrino flux upper limit for this source of E^2 dN/ dE = 5.1 x 10^-2 GeV cm^-2 at 90% CL, under the assumption of an E^-2 power law. 90% of events IceCube would detect from a source at this declination with an E^-2 spectrum have energies in the approximate energy range between 600 GeV and 300 TeV.

A subsequent search was performed including 2 days of data centered on the Fermi-GBM trigger (2023-08-11 18:58:12.05 UTC to 2023-08-13 18:58:12.05 UTC). In this case, we report a p-value of 1.0, consistent with background expectation. We accordingly derive a time-integrated muon-neutrino flux upper limit for this source of E^2 dN/ dE = 5.4 x 10^-2 GeV cm^-2 at 90% CL, under the assumption of an E^-2 power law. 

The IceCube Neutrino Observatory is a cubic-kilometer neutrino detector operating at the geographic South Pole, Antarctica. The IceCube realtime alert point of contact can be reached at roc@icecube.wisc.edu.

[1] IceCube Collaboration, R. Abbasi  et al., ApJ 910 4 (2021)


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34428
SUBJECT: GRB 230812B: further SAO RAS optical observations
DATE:    23/08/15 00:02:33 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin and O. I. Spiridonova (SAO RAS), report on behalf of
the GRB follow-up team.

We observed the field of GRB 230812B (Lesage et al., GCN 34387;
Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN
34395; Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley
et al., GCN 34398; Xiong et al., GCN 34401; Casentini et al., GCN
34002; Frederiks et al., GCN 34403; Mao et al., GCN 34404; Odeh et
al., GCN 34405; Moskvitin & Spiridonova GCN 34406; Leonini et al. GCN
34408; de Ugarte Postigo et al. GCN 34409; de Ugarte Postigo et al.
GCN 34410; Belkin et al. GCN 34412; Ruocco et al. GCN 34413; Frederiks
et al. GCN 34414; Ruocco et al. GCN 34415; Shrestha et al. GCN 34416;
Quadri et al. GCN 34417; Adami et al. GCN 34418; Moretti et al. GCN
34419; Kumar et al. GCN 34420; Belkin et al. GCN 34421 & GCN 34423;
Pyshna et al., GCN 34425) with the 1-m telescope of SAO RAS Zeiss-1000
equipped with the CCD photometer. We obtained 5 x 300 sec. images in
Rc band on August 14, 19:51:04--20:21:03 UT

The OT is clearly detected in our stacked frame with the brightness of
R = 21.20 +/- 0.09 (t_mid - t0 = 2.0471 days).

This preliminary photometry is based on the nearby SDSS stars;
magnitudes are converted using Lupton (2005) equations.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34432
SUBJECT: GRB 230812B: continued AbAO optical afterglow observations
DATE:    23/08/15 09:36:05 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

S. Belkin (IKI),  R. Ya. Inasaridze (AbAO),  A. Pozanenko (IKI), N. Pankov (HSE, IKI) report on behalf of GRB IKI FuN:

We observed the field of GRB 230812B (Fermi GBM Team, GCN 34386; Scotton et al., GCN 34392; Page et al. GCN 34394; Kuin et al., GCN 34399; Casentini et al., GCN 34402) with AS-32 telescope of Abastumani observatory (AbAO) in R-filter starting on Aug. 14 (UT) 17:47:21. We  detected the  afterglow (Lesage et al., GCN 34387; Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN 34395; Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley et al., GCN 34398; Xiong et al., GCN 34401; Casentini et al., GCN 34402; Frederiks et al., GCN 34403; Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin et al., GCN 34406; Leonini et al., GCN 34408; de Ugarte Postigo et al., GCNs 24409, 34410; Belkin et al. GCN 34412; Ruocco et al. GCN 34413; Frederiks et al. GCN 34414; Ruocco et al. GCN 34415; Shrestha et al. GCN 34416; Quadri et al. GCN 34417; Adami et al. GCN 34418; Moretti et al. GCN 34419; Kumar et al. GCN 34420; Belkin et al. GCN 34421 & GCN 34423; Pyshna et al!
 ., GCN 34425) in the stacked image. Preliminary photometry of the object is following

Date       UT start   t-T0    Filter Exp.    OT    Err.   UL(3sigma)
                       (mid, days)    (s)

2023-08-14 17:47:21   1.99199  R     94*60  21.16  0.21   22.0

The photometry is based on nearby SDSS stars used in (Moskvitin et al, GCN 34406):
RA DEC R (Lupton)
16:36:35.9365104 +47:52:54.574320 14.893 0.008
16:36:32.6835360 +47:53:44.537784 16.531 0.009
16:36:25.6055880 +47:53:20.456304 16.827 0.009
16:36:25.1691816 +47:52:20.931816 16.068 0.008
16:36:44.6580984 +47:50:56.806944 15.785 0.008
16:36:40.1374488 +47:54:02.128752 15.698 0.008


GRB_name: GRB230812B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34433
SUBJECT: GRB 230812B: AMI-LA radio detection of afterglow candidate
DATE:    23/08/15 10:57:05 GMT
FROM:    Lauren Rhodes at Oxford <lauren.rhodes@physics.ox.ac.uk>

Lauren Rhodes, Joe Bright, Rob Fender (Oxford), Dave Green, Dave Titterington (Cambridge) report:

We observed the field of the gamma-ray burst GRB 230812B (GCN 34286) with the Arcminute Microkelvin Imager Large-Array (AMI-LA) at 15.5 GHz beginning at UT 18:13:51.9 on 14-Aug-2023 for a total of 4 hours. The flux standard 3c286 was used to calibrate the bandpass response and flux scale of the AMI-LA and J1658+4737 was used as an interleaved complex gain calibrator.
We detect a unresolved source at a position consistent with the one reported in GCN 34394 with a (preliminary) peak flux density of 280uJy/beam. The rms noise in the field is 40uJy/beam. Further observations are planned.

We thank the staff at the Mullard Radio Astronomy Observatory for carrying out these observations and operating the AMI-LA.


GRB_name: GRB230815A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34434
SUBJECT: GRB 230815A: Swift detection of a burst
DATE:    23/08/15 11:25:59 GMT
FROM:    K.L. Page at U Leicester <klp5@leicester.ac.uk>


N. J. Klingler (GSFC/UMBC/CRESSTII), C. Gronwall (PSU),
K. L. Page (U Leicester), D. M. Palmer (LANL) and
T. M. Parsotan (GSFC/UMBC/CRESSTII) report on behalf of the Neil
Gehrels Swift Observatory Team:

At 10:49:55 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 230815A (trigger=1185505).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 184.772, -58.065 which is 
   RA(J2000) = 12h 19m 05s
   Dec(J2000) = -58d 03' 53"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 2 sec.  The peak count rate
was ~6000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 10:52:04.0 UT, 128.1 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
uncatalogued X-ray source located at RA, Dec 184.72347, -58.05386 which
is equivalent to:
   RA(J2000)  = 12h 18m 53.63s
   Dec(J2000) = -58d 03' 13.9"
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This
position may be improved as more data are received; the latest position
is available at https://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (4.94 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 7.8
(+3.75/-3.24) x 10^21 cm^-2 (90% confidence). 

The initial flux in the 2.5 s image was 2.07e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 155 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of
the XRT error circle. Because of the density of catalogued stars, further
analysis is required to report an upper limit for any afterglow in the
sub-image. Data from the list of sources generated on-board are not available
at this time. No correction has been made for the large, but uncertain,
extinction expected. 

Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34435
SUBJECT: GRB 230812B: Tautenburg observations
DATE:    23/08/15 13:55:41 GMT
FROM:    Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>


S. Klose, S. Melnikov, B. Stecklum, A. Nicuesa Guelbenzu, and F. Ludwig (all TLS Tautenburg) report:

We observed the field of GRB 230812B (Lesage et al., GCN 34387; Roberts et al., GCN 34391; Scotton et al., GCN 34392; Xiong et al., GCN 34401; Casentini et al., GCN 34402; Frederiks et al., GCN 34403) with the Tautenburg 1.34m Schmidt telescope equipped with the TAUKAM 6k x 6k CCD camera. Observations consisted of 3 x 90 sec exposures using the Sloan g, r, and i-band filter.

For the optical transient (first reported by Zheng et al., GCN 34395, and Lipunov et al, GCN 34396) we measure the following preliminary AB magnitudes (2.19 days post burst):

g = 21.85 +/- 0.25  (midtime: August 14, 2023, 23:23:33 UT),

r = 21.28 +/- 0.13  (midtime: August 14, 2023, 23:30:37 UT),

i = 21.29 +/- 0.14  (midtime: August 14, 2023, 23:37:44 UT),

calibrated against SDSS stars in the field.


GRB_name: GRB230812B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34436
SUBJECT: GRB 230812B: Iota Scorpii Observatory, La Spezia, Italy
DATE:    23/08/15 14:09:22 GMT
FROM:    GIULIO SCARFI at IOTA SCORPII OBSERVATORY <terziaria@gmail.com>

Giulio ScarfÃ¬  (Iota Scorpii Observatory, La Spezia,Italy)
mail terziaria@gmail.com

In a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan),
Y. Niino (Tokyo University, Institute of Astronomy),
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)

Members of:

GAD - Gruppo Astronomia Digitale.
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili-GRB.

report:

I have observed the field of GRB 230812B (Lesage et al., GCN 34387;
Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN
34395; Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley
et al., GCN 34398; Xiong et al., GCN 34401; Casentini et al., GCN
34002; Frederiks et al., GCN 34403; Mao et al., GCN 34404; Odeh et
al., GCN 34405; Moskvitin & Spiridonova GCN 34406; Leonini et al. GCN
34408; de Ugarte Postigo et al. GCN 34409; de Ugarte Postigo et al.
GCN 34410; Belkin et al. GCN 34412; Ruocco et al. GCN 34413; Frederiks
et al. GCN 34414; Ruocco et al. GCN 34415; Shrestha et al. GCN 34416;
Quadri et al. GCN 34417; Adami et al. GCN 34418; Moretti et al. GCN
34419; Kumar et al. GCN 34420; Belkin et al. GCN 34421 & GCN 34423;
Pyshna et al., GCN 34425) with my 0.40-m Ritchey-Cretien telescope.

The observations started 1660 min after the GRB trigger, at the end of
twilight,
with a Ritchey Cretien D=406 mm with reducer F/D=6,15.
Weather conditions were good.


Add 12 x 300 sec. unfiltered images on August 13 2023,
from 20:26:35 to 21:21:42 UT


Start T0+      End T0+       R lim
1660 min        1735 min         20


I confirm a fading afterglow


The results of photometry are:


      JD         mag      Err   Flt

2460170.36555307   19.85  +/- 0.2   CLEAR


Magnitudes were estimated with the Atlas catalog and
are not corrected for galactic dust extinction.



Reference:
http://www.iotascorpiiobservatory.it



The message may be cited.


GRB_name: GRB230815A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34437
SUBJECT: GRB 230815A: Enhanced Swift-XRT position
DATE:    23/08/15 16:44:53 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 927 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 230815A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 184.72225, -58.05290 which is equivalent
to:

RA (J2000): 12h 18m 53.34s
Dec (J2000): -58d 03' 10.4"

with an uncertainty of 2.2 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB230814A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34438
SUBJECT: Fermi GRB 230814A: Global MASTER-Net observations report
DATE:    23/08/15 18:01:46 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-Tavrida robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 230814A ( Fermi GBM team, GCN 34422) errorbox  82226 sec after notice time and 82259 sec after trigger time at 2023-08-15 17:45:55 UT, with upper limit up to  16.4 mag. Observations started at twilight.  The observations began at zenith distance = 61 deg. The sun  altitude  is -10.2 deg. 

The galactic latitude b = -12 deg., longitude l = 23 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2254257

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

   82290 | 2023-08-15 17:45:55 |      MASTER-Tavrida | (19h 18m 54.47s , -11d 57m 39.1s) |   C |    60 | 16.2 |        
   82364 | 2023-08-15 17:47:10 |      MASTER-Tavrida | (19h 02m 19.60s , -17d 37m 39.4s) |   C |    60 | 16.4 |        
   82438 | 2023-08-15 17:48:23 |      MASTER-Tavrida | (19h 18m 19.74s , -17d 38m 18.6s) |   C |    60 | 16.4 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230815A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34439
SUBJECT: Swift GRB 230815A: Global MASTER-Net observations report
DATE:    23/08/15 19:54:30 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 230815A ( N. J. Klingler et al., GCN 34434) errorbox  27081 sec after notice time and 28191 sec after trigger time at 2023-08-15 18:41:55 UT, with upper limit up to  17.4 mag. The observations began at zenith distance = 58 deg. The sun  altitude  is -32.4 deg. 

The galactic latitude b =  4 deg., longitude l = 299 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2254590

We obtain a following upper limits.  

Tmid-T0  |          Site       |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________

   28282 |         MASTER-SAAO |   C |   180 | 16.8 |        
   29125 |         MASTER-SAAO |   C |   180 | 17.4 |        
   29335 |         MASTER-SAAO |   C |   180 | 17.3 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230815A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34440
SUBJECT: GRB 230815A: Fermi GBM detection
DATE:    23/08/15 20:38:44 GMT
FROM:    Bagrat Mailyan at Florida Tech <mbagrat@gmail.com>

B. Mailyan (Florida tech), A. von Kienlin (MPE) and C. Meegan (UAH) report on behalf of
the Fermi Gamma-ray Burst Monitor Team:

"At 10:49:54.66 UT on 15 August 2023, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 230815A (trigger 713789399/230815451).
which was also detected by Swift BAT (N. J. Klingler et al. 2023, GCN 34434).
The Fermi GBM on-ground location is consistent with the Swift BAT position.

The angle from the Fermi LAT boresight is 159 degrees.

The GBM light curve consists of a single emission episode with a duration (T90)
of about 5.2 s (50-300 keV). The time-averaged spectrum
from T0+0.002 to T0+3.264 s is best fit by
a Band function with Epeak = 235 +/- 25 keV,
alpha = -0.6 +/- 0.1, and beta = -2.22 +/- 0.09.

The event fluence (10-1000 keV) in this time interval is
(1.20 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.1 s in the 10-1000 keV band is 27 +/- 2 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"


GRB_name: GRB230815A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34441
SUBJECT: GRB230815A: BOOTES-6/DPRT optical upper limit 
DATE:    23/08/15 21:30:53 GMT
FROM:    Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>

E. Fernandez-Garcia, Y.-D. Hu, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy and A. J. Castro-Tirado (IAA-CSIC, Granada), P. J. Meintjes and H. J. van Heerden (UFS, SouthAfrica), A. Martin-Carrillo and L. Hanlon (UCD, Ireland) and C. J. Perez del Pulgar (UMA, Malaga), on behalf of a larger collaboration, report:

Following the detection of GRB 230815A by Swift (Klingler et al. GCNC 34434) and Fermi (Mayland et al. GCNC 34440), the BOOTES-6/DPRT 0.6m robotic telescope at Boyden Observatory in Maselspoort (South Africa) automatically observed the GRB location starting on Aug. 15, 19:21 UT (~ 8.5 h after trigger). No new optical source is detected on the co-added image (5 x 60 s, clear filter) within the enhanced Swift/XRT error region (Beardmore et al. GCNC 34437) down to 19.5 mag.

We thank the staff at Boyden Observatory for their excellent support.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34442
SUBJECT: GRB 230812B: continued SAO RAS optical observation
DATE:    23/08/16 01:28:09 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin and O. I. Spiridonova (SAO RAS),
report on behalf of the GRB follow-up team.

We observed the field of GRB 230812B (Fermi GBM Team, GCN 34386;
Scotton et al., GCN 34392; Page et al. GCN 34394; Kuin et al.,
GCN 34399; Casentini et al., GCN 34402) with the 1-m telescope
of SAO RAS Zeiss-1000 equipped with the CCD photometer. We obtained
8 x 300 sec. images in Rc band on 19:02:23--20:57:14 UT and
8 x 300 sec. images in B  band on 19:45:22--21:08:27 UT (August 15).

The OT (Lesage et al., GCN 34387; Scotton et al., GCN 34392; Page,
GCN 34394; Zheng & Filippenko, GCN 34395; Lipunov et al., GCN 34396;
Salgundi et al., GCN 34397; Ackley et al., GCN 34398; Xiong et al.,
GCN 34401; Casentini et al., GCN 34402; Frederiks et al., GCN 34403;
Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin & Spiridonova,
GCN 34406; Leonini et al., GCN 34408; de Ugarte Postigo et al.,
GCNs 24409, 34410; Belkin et al. GCN 34412; Ruocco et al. GCN 34413;
Frederiks et al. GCN 34414; Ruocco et al. GCN 34415; Shrestha et al.
GCN 34416; Quadri et al. GCN 34417; Adami et al. GCN 34418;
Moretti et al. GCN 34419; Kumar et al. GCN 34420; Belkin et al. GCNs
34421, GCN 34423; Pyshna et al., GCN 34425; Moskvitin & Spiridonova,
GCN 34428; Quadri & Strabla, GCN 34430; Mihov et al., GCN 34431;
Belkin et al. GCN 34432; Klose et al., GCN 34435; Scarfi, GCN 34436)
is clearly detected in our stacked frames with the brightness of
R = 21.40 +/- 0.06 (t_mid - t0 = 3.0428 days),
B = 22.23 +/- 0.09 (t_mid - t0 = 3.0616 days).

This preliminary photometry is based on the nearby SDSS stars;
magnitudes are converted using Lupton (2005) equations.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34443
SUBJECT: GRB 230812B: iTelescope optical upper limit
DATE:    23/08/16 04:27:25 GMT
FROM:    Filipp Dmitrievich Romanov at Amateur astronomer <filipp.romanov.27.04.1997@gmail.com>

I observed the field of GRB 230812B (Fermi GBM team, GCN Circ. 34386)
remotely using telescope T24 (0.61-m f/6.5 reflector + CCD) of
iTelescope.Net in Sierra Remote Observatory (Auberry, California, USA)
on 2023-08-14. Six images (exposures 300 seconds, BINx1) were obtained
with Ic filter with mid time 05:10:04 UT (1.424 d. after the trigger).
I did not detect any optical afterglow in the Swift/XRT (Page, GCN
Circ. 34394) position. The magnitude limit is about 19 mag, compared
to the magnitudes of nearby stars from the USNO-B1.0 Catalog (Monet et
al., 2003).
F. D. Romanov (AAVSO member, observer code: RFDA).


GRB_name: GRB230815A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34444
SUBJECT: GRB 230815A: Swift-XRT refined Analysis
DATE:    23/08/16 05:16:53 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), D.N. Burrows (PSU),
J. D. Gropp (PSU), S. Dichiara (PSU), J.P. Osborne (U. Leicester), K.L.
Page (U. Leicester), A.P. Beardmore (U. Leicester), E. Ambrosi 
(INAF-IASFPA)  and P.A. Evans report on behalf of the Swift-XRT team:

We have analysed 6.0 ks of XRT data for GRB 230815A, from 117 s to 45.2
ks after the  BAT trigger. The data comprise 574 s in Windowed Timing
(WT) mode (the first 9 s were taken while Swift was slewing) with the
remainder in Photon Counting (PC) mode. 

The late-time light curve (from T0+6.1 ks) can be modelled with a
power-law decay with a decay index of alpha=1.94 (+0.25, -0.29).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.92 (+0.06, -0.05). The
best-fitting absorption column is  7.4 (+0.5, -0.4) x 10^21 cm^-2, in
excess of the Galactic value of 4.9 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.94 (+0.18, -0.17)
and a best-fitting absorption column of 9.1 (+1.7, -1.5) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.9 x 10^-11 (8.5 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      9.1 (+1.7, -1.5) x 10^21 cm^-2
Galactic foreground: 4.9 x 10^21 cm^-2
Excess significance: 4.5 sigma
Photon index:      1.94 (+0.18, -0.17)

If the light curve continues to decay with a power-law decay index of
1.94, the count rate at T+24 hours will be 2.5 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-13 (2.1 x 10^-13) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01185505.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34445
SUBJECT: GRB 230812B: GAD Observatory optical observations (upper limit)
DATE:    23/08/16 10:38:15 GMT
FROM:    Claudio Lopresti <cl3lop@gmail.com>

Claudio Lopresti (Gruppo Astronomia Digitale - GAD Observatory, La Spezia, Italy),
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan),
Y. Niino (Tokyo University, Institute of Astronomy),
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report:

I imaged the field of GRB 230812B (Lesage et al., GCN 34387;
Scotton et al., GCN 34392; Page, GCN 34394; Zheng & Filippenko, GCN 34395;
Lipunov et al., GCN 34396; Salgundi et al., GCN 34397; Ackley et al., GCN 34398;
Xiong et al., GCN 34401; Casentini et al., GCN 34002; Frederiks et al., GCN 34403;
Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin et al., GCN 34406)
detected by FERMI(trigger 713559497.049606 / 230812790)
with the GAD Observatory, La Spezia, Italy Italy.

Member of:
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili, GRB section
GAD - Gruppo Astronomia Digitale

The observations started 48.02 hour after the FERMI trigger, At the end of twilight
with a Maksutov-Newton telescope D=180 mm F/D=4

Weather conditions were good.

We co-added  series of 8 exposures of 60 sec each.

Start T0+        End T0+          R lim
3168 min       3178 min         19.6

I did not detect any optical afterglow in the Swift/XRT (Page, GCN
Circ. 34387) position. The magnitude limit is about 19.5 mag, compared
to the magnitudes of nearby stars from the Gaia EDR3 Catalog

Magnitudes were estimated with the Gaia EDR3 cat. and
are not corrected for galactic dust extinction.

Reference:
https://www.parcodellestelle.com/

The message may be cited. 


GRB_name: GRB230815A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34446
SUBJECT: GRB230815A: Swift/UVOT upper limits
DATE:    23/08/16 12:42:08 GMT
FROM:    Alice Breeveld at MSSL-UCL <a.breeveld@ucl.ac.uk>

A. A. Breeveld (UCL-MSSL) and N. J. Klingler (GSFC/UMBC/CRESSTII) report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 230815A 155 s after the BAT trigger (Klingler et al., GCN Circ. 34434).
No optical afterglow consistent with the XRT position (Beardmore et al., GCN Circ. 34437) is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent summed exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC           155          305        147           >20.1
white              513         1531        242           >20.3
v                  390         1582        136           >18.5
b                  489         1506        114           >19.3
u                  464         6300        293           >19.4
uvw1               439         1632        136           >18.6
uvm2               761         1606         97           >18.3
uvw2               365         1557        136           >18.8

The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.73 in the direction of the burst (Schlegel et al. 1998).


GRB_name: GRB230815B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34447
SUBJECT: GRB 230815B: AstroSat CZTI detection
DATE:    23/08/16 14:06:03 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>

B. Pari (IITB), P K. Navaneeth (IUCAA), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long GRB 230815B which was also detected by GECAM-B (TrigNum 211).

The source was clearly detected in the 20-200 keV energy range. The light curve peaks at 2023-08-15 16:08:28.5 UTC. The measured peak count rate associated with the burst is 271.4 (+40.4, -41.4) counts/s above the background in the combined data of all quadrants, with a total of 2148 (+375, -381) counts. The local mean background count rate was 335.7 (+2.4, -3.0) counts/s. Using cumulative rates, we measure a T90 of 33.2 (+8.9, -11.6) s. 

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve peaks at 2023-08-15 16:08:27.3 UTC. The measured peak count rate associated with the burst is 725.5 (+75.8, -66.6) counts/s above the background in the combined data of all quadrants, with a total of 9598 (+1234, -1292) counts. The local mean background count rate was 1481.2 (+5.7, -6.9) counts/s. We measure a T90 of 43.5 (+8.7, -12.6) s from the cumulative Veto light curve.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at: 
http://astrosat.iucaa.in/czti/?q=grb


GRB_name: GRB230815B
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34448
SUBJECT: GRB 230815B: GECAM-B and GECAM-C detection of a burst
DATE:    23/08/16 14:16:52 GMT
FROM:    Yunfei Du at IHEP <duyunfei@ihep.ac.cn>

Shaolin Xiong, Yanqiu Zhang, Yue Huang report on behalf of the GECAM team:

GECAM-B and GECAM-C were triggered in-flight by a long burst, GRB 230815B,
at 2023-08-15T16:07:29.150 UTC and 2023-08-15T16:07:29.350 UTC, respetively,
which was also observed by INTEGRAL/SPI-ACS and Konus-Wind.

According to the realtime alert data of GECAM-B and GECAM-C, this burst
mainly consists of a bright short pulse followed by a broad pulse with
a total duration (T90) of about ~30 sec (15-1000 keV).

Using the automatic on-ground localization pipeline with the realtime alert data, 
GECAM-B localized this burst to the following position (J2000): 
RA: 325.9 deg 
DEC: 13.2 deg
Err: 5.1 deg (1-sigma, statistical only)
The systematic error of this location is estimated to be several degrees.

The time-averaged spectrum of GECAM-B realtime data shows that it could be
adequately fit by a Band function with a fluence about 1.6E-5 erg/cm^2 in 20-1000 keV. 

We note that these results are based on realtime alert data and thus very preliminary. 
Refined analysis will be reported later.

Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor
(GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B)
launched in Dec. 2020. As the third member of GECAM constellation, 
GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. 
GECAM mission is funded by the Chinese Academy of Sciences (CAS).


GRB_name: GRB230815A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34449
SUBJECT: GRB 230815A: Swift-BAT refined analysis
DATE:    23/08/16 16:03:55 GMT
FROM:    Tyler Parsotan  at NASA GSFC <tyler.parsotan@nasa.gov>

S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC),
H. A. Krimm (NSF), A. Y. Lien (U Tampa),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU),
M. Stamatikos (OSU) (i.e. the Swift-BAT team):


Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 230815A (trigger #1185505)
(Klingler, et al., GCN Circ. 34434). The BAT ground-calculated position is
RA, Dec = 184.760, -58.067 deg which is
RA(J2000) = 12h 19m 02.4s
Dec(J2000) = -58d 03' 59.5"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 11%.


The mask-weighted light curve shows a strong peak at trigger time with precursor emission
At T-14 sec from trigger. T90 (15-350 keV) is 17.00 +- 7.62 sec (estimated error including systematics).


The time-averaged spectrum from T-14.78 to T+9.22 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.19 +- 0.10. The fluence in the 15-150 keV band is 5.2 +- 0.3 x 10^-06 erg/cm2.
The 1-sec peak photon flux measured from T+0.22 sec in the 15-150 keV band
is 13.7 +- 1.1 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.


The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/1185505/BA/


GRB_name: GRB230816A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34450
SUBJECT: GRB 230816A: Swift detection of a burst
DATE:    23/08/16 16:24:41 GMT
FROM:    David Palmer at LANL <palmer@lanl.gov>


M. H. Siegel (PSU), S. Dichiara (PSU),
R. A. J. Eyles-Ferris (U Leicester), J.D. Gropp (PSU),
J. A. Kennea (PSU), F. E. Marshall (NASA/GSFC), M. J. Moss (GWU),
K. L. Page (U Leicester), D. M. Palmer (LANL),
T. M. Parsotan (GSFC/UMBC/CRESSTII), B. Sbarufatti (INAF-OAB) and
M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 16:08:48 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 230816A (trigger=1185673).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 328.375, +37.828 which is 
   RA(J2000) = 21h 53m 30s
   Dec(J2000) = +37d 49' 43"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 25 sec.  The peak count rate
was ~1900 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 16:10:18.4 UT, 90.2 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 328.44552,
37.85549 which is equivalent to:
   RA(J2000)  = 21h 53m 46.92s
   Dec(J2000) = +37d 51' 19.8"
with an uncertainty of 1.9 arcseconds (radius, 90% containment). This
location is 223 arcseconds from the BAT onboard position. This position
may be improved as more data are received; the latest position is
available at https://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (2.90 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 3.7
(+3.48/-2.91) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 93 seconds after the BAT trigger. No credible afterglow candidate has
been found in the initial data products. The 2.7'x2.7' sub-image covers none of
the XRT error circle. The 8'x8' region for the list of sources generated
on-board covers 100% of the XRT error circle. The list of sources is typically
complete to about 18 mag. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.311. 

Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/)


GRB_name: GRB230815A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34452
SUBJECT: GRB 230815A: SOAR/Goodman follow-up imaging
DATE:    23/08/16 18:03:23 GMT
FROM:    Charles Kilpatrick at Northwestern U <ckilpatrick@northwestern.edu>

C. D. Kilpatrick (Northwestern), C. R. Bom (CBPF), A. Santos (CBPF/Fermilab), S. Panda (LNA), Felipe Navarete (NOIRLab/SOAR) on behalf of a larger collaboration, report:

Following the detection of GRB230815A (Klingler et al., GCN 34434, Mailyan et al., GCN 34440), we triggered observations with the Goodman high-throughput imaging spectrograph on the SOAR 4.1m telescope at Cerro PachÃ³n, Chile.  Targeting the site of the reported Swift/XRT counterpart (Beardmore et al., GCN 34437), we obtained 6x180s exposures in SDSS i-band and 7x180s in SDSS z-band at start times of 2023-08-15 23:17:36 and 2023-08-15 23:50:48 UTC, respectively.  We did not detect a counterpart in either stacked image, with the limiting magnitude in both frames significantly affected by poor atmospheric transparency.  Performing forced photometry at the site of the XRT counterpart (R.A.=12:18:53.34, Decl.=-58:03:10.4), we derive limits on an optical counterpart of:

MJD Filter Maglimit
60171.97055 i 20.5
60171.99361 z 17.9

Both magnitude limits are on the AB magnitude system calibrated from SkyMapper DR2 standard stars (Onken et al. 2019) and are not corrected for the significant Galactic extinction along this sight line (A_i=1.25 mag, A_z=0.93 mag).

Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the MinistÃ©rio da CiÃªncia, Tecnologia e InovaÃ§Ãµes do Brasil (MCTI/LNA), the US National Science Foundationâ€™s NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).


GRB_name: GRB230816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34453
SUBJECT: GRB 230816A: Nanshan/HMT optical afterglow detection
DATE:    23/08/16 18:15:50 GMT
FROM:    Dong Xu at NAOC/CAS <dxu@nao.cas.cn>

S.Q. Jiang, S.Y. Fu, X. Liu, T.H. Lu, Z.P. Zhu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:

We observed the field of GRB 230816A detected by Swift (Siegel et al., GCN 34450) using the HMT-0.5m telescope located at Nanshan, Xinjiang, China. Observations started at 16:10:20 UT on 2023-08-16, i.e., 92 s after the Swift/BAT trigger, we obtained a serise of 3x20, 3x40, 4x60, 12x90 s frames without any filter.

An uncatalogued optical source is detected in our stacked image at coordinates

R.A. (J2000) = 21:53:46.9
Dec. (J2000) = +37:51:15.9

2.23 arcsec away from the center of the XRT error circle (radius: 1.9 arcsec, 90% containment; Siegel et al., GCN 34450) with m(r) = 19.6 +/- 0.18 mag(AB) at 24.6 min post-burst, calibrated with the nearby PanSTAR field in the Sloan r-filter and the magnitude is not corrected for Galactic extinction. We thus think this OT is the optical afterglow of the burst.


GRB_name: GRB230815B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34454
SUBJECT: IPN triangulation of GRB 230815B
DATE:    23/08/16 18:47:08 GMT
FROM:    Anna Ridnaia at Ioffe Institute <ridnaia@mail.ioffe.ru>

A.S. Kozyrev, D.V. Golovin, M.L. Litvak, I.G. Mitrofanov, and A.B. Sanin
on behalf of the HEND/Mars Odyssey team,

A. Ridnaia, D. Frederiks, D. Svinkin, A. Lysenko,
and T. Cline on behalf of the Konus-Wind team,

E. Bozzo and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team,

and

W. Boynton, C. Fellows, K. Harshman, H. Enos, R. Starr,
and A.S. Gardner on on behalf of the GRS-Odyssey GRB team,
report:

The long-duration GRB 230815B
(AstroSat CZTI detection: Pari et al., GCN 34447;
GECAM-B and GECAM-C detection: Xiong et al., GCN 34448)
has been detected by Konus-Wind, INTEGRAL (SPI-ACS),
Swift (BAT), AstroSat (CZTI), GECAM-B, GECAM-C,
and Mars-Odyssey (HEND), so far, at about 58049 s UT (16:07:29).
The burst was outside the coded field of view of the BAT.

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
 ---------------------------------------------
  RA(2000), deg                 Dec(2000), deg
 ---------------------------------------------
 Center:
  307.334 (20h 29m 20s)  +4.190 ( +4d 11' 24")
 Corners:
  307.122 (20h 28m 29s)  +2.976 ( +2d 58' 33")
  307.518 (20h 30m 04s)  +5.411 ( +5d 24' 38")
  307.571 (20h 30m 17s)  +5.398 ( +5d 23' 53")
  307.175 (20h 28m 42s)  +2.963 ( +2d 57' 47")
 ---------------------------------------------
The error box area is 487 sq. arcmin, and its maximum
dimension is 2.5 deg (the minimum one is 3 arcmin).
The Sun distance was 154 deg.

This localization may be improved.

A triangulation map and HEALPix FITS file are posted at
http://www.ioffe.ru/LEA/GRBs/GRB230815_T58054/IPN

The Konus-Wind time history and spectrum will be given
in a forthcoming GCN Circular.


GRB_name: GRB230816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34456
SUBJECT: GRB 230816A: SAO RAS optical observations
DATE:    23/08/16 19:26:01 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin and O. I. Spiridonova (SAO RAS),
report on behalf of the GRB follow-up team.

We observed the field of the GRB 230816A (Siegelet al., GCN 34450)
with the 1-m telescope of SAO RAS Zeiss-1000 equipped with the CCD
photometer. We obtained 8 x 300 sec. images in Rc band on August 16,
17:45:41 -- 18:35:29 UT.

The OT (Jiang et al., GCN 34453) is clearly detected in our stacked
frame with the coordinates
R.A. (J2000) = 21:53:46.9,
Decl.(J2000) = +37:51:16.7 (+/- 0".5)
and the brightness of R = 21.0 +/- 0.1 (t_mid - t0 = 2.030h = 0.0846d).

This preliminary photometry is based on nearby USNO-B1 stars (R2 mag),
the magnitude is not corrected for MW extinction.


GRB_name: GRB230816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34457
SUBJECT: GRB 230816A: TShAO and Assy  optical observations
DATE:    23/08/16 20:29:24 GMT
FROM:    Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>

N. Pankov (HSE, IKI), I. Reva (FAI), V. Kim (FAI), A. Pozanenko (IKI), S. Belkin (IKI) report on behalf of the GRB-IKI-FuN.

We observed the field of the GRB 230816A (Siegel et al., GCN 34450)
with Zeiss-1000 telescope of Tien-Shan Observatory (TShAO) and AZT-20 telescope of Assy Observatory. We clearly detect the afterglow (Jiang et al., GCN 34453; Moskivitin et al., GCN 34456) in the stacked images. 

Preliminary photometry is following

Date       UT start   t-T0    Filter Exp.   OT    Err.  UL(3sigma)
                      (mid, days)    (s)

2023-08-16 16:21:24   0.034787  R    25*180 19.57   0.10  22.3   
2023-08-16 17:26:29   0.072354  r'   53*60  21.10|  0.025 23.5   

The photometry is based on nearby stars of USNO-B1.0 and PanSTARRS-DR1 catalogues.
RA Dec R2 r'
328.5043802 +37.8674441 16.47 16.8245
328.3579777 +37.8706420 17.04 17.1589
328.4483771 +37.8290610 15.45 15.3054


GRB_name: GRB230816A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34458
SUBJECT: GRB 230816A: AKO Optical Observations
DATE:    23/08/16 20:58:15 GMT
FROM:    Mohammad Odeh at Al Khatim Observatory M44 <mshodeh@gmail.com>

Mohammad Odeh, Nada Odeh, Osama Ghannam, Anas Mohammad, and Khalfan
Al-Noaimy, report on behalf of Al-Khatim Observatory (AKO) operated by the
International Astronomical Center in Abu Dhabi, UAE:

We observed the field of the GRB 230816A (Siegel et al., GCN 34450) with
our 0.36m f/7.7 robotic telescope. We obtained 21 x 180 sec. images in a
clear filter on 16 August, from 19:05 to 20:36 UT.

We detected the afterglow (Jiang et al., GCN 34453; Moskivitin et al., GCN
34456; Pankov et al., GCN 34457) in our stacked images with the coordinates
(J2000) R.A.= 21:53:47.01, Dec.= +37:51:16.7 and the brightness of Mv =
20.6 +/- 0.27 (t_mid - t0 = 3.7 hours).

The magnitude is not corrected for galactic extinction.


GRB_name: GRB230816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34459
SUBJECT: GRB 230816A: Tautenburg observations
DATE:    23/08/16 21:06:26 GMT
FROM:    Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>


S. Klose, S. Melnikov, B. Stecklum, A. Nicuesa Guelbenzu, F. Ludwig (all TLS Tautenburg) report:

We observed the field of GRB 230816A (Siegel et al., GCN 34450) with the Tautenburg 1.34m Schmidt telescope equipped with the TAUKAM 6kx6k CCD camera and using the Sloan filter set.

For the optical transient discovered by Jiang et al. (GCN 34453) we measure the following preliminary magnitudes:

r = 21.75 +/- 0.25  (midtime: August 16, 2023, 20:23:11 UT),

i = 20.33 +/- 0.08  (midtime: August 16, 2023, 20:34:05 UT),

calibrated against USNO stars in the field. The photometry will still be improved by calibrating the data via a nearby Pan-STARRS field.


GRB_name: GRB230816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34460
SUBJECT: GRB230816A: Possible host and GIT detection of optical counterpart
DATE:    23/08/16 22:08:37 GMT
FROM:    Vishwajeet Swain at IIT Bombay <vishwajeet.s@iitb.ac.in>

R. Kumar (IITB), R. Sharma (IITB), V. Swain (IITB), A. Salgundi (IITB), H. Kumar (IITB), G. Waratkar(IITB), V. Bhalerao (IITB), G. C. Anupama(IIA), S. Barway (IIA) and K. Angail (IAO) report on behalf of the GIT team:

We observed the field of GRB 230816A detected by SWIFT (Siegel  et al., GCN 34450) with 0.7m GROWTH-India Telescope (GIT). We started observations at 16:40:00 UT, i.e., 31.2 mins after the Swift/BAT trigger. We obtained 5 frames in the r' band of 300 sec each. After image subtraction, we detected a source in our stacked image at RA 21:53:46.96, Dec: +37:51:16.08 with an uncertainty of 0.67 arcsec - coincident with the reported afterglow (Jiang et al., GCN 34453), and 3.75 arsec away from center of the XRT error circle (Siegel et al., GCN 34450). 

We note that there is a faint source (m_r ~ 23.0) nearly coincident with the counterpart in the Pan-STARRS1 images, which could be a host of this GRB. Our image subtraction ensures that this source flux does not affect out photometric measurements. There is no minor planet present at this position. The photometric results are as follows:

----------------------------------------------------------------------

 JD (mid) | T_mid-T0 (mins) | Exposure (sec) | Filter | Magnitude (AB) |

----------------------------------------------------------------------

 2460173.202193 | 42.35  | 5 x 300 | r' | 20.61 +/- 0.06  |

----------------------------------------------------------------------

Our results are consistent with other reports (Jiang et al. GCN 34453, Moskvitin et al., GCN 34456, Pankov et al., GCN 34457, Odeh et al., GCN 34458, Klose et al., GCN 34459). We encourage photometric for further confirmation and spectroscopic follow-up for redshift measurement. The magnitudes are calibrated against PanSTARRS DR1 (Chambers et al., 2016) and are not corrected for Galactic extinction.

The GROWTH India Telescope (GIT; Kumar et al. 2022) is a 70-cm telescope with a 0.7-degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports the operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34461
SUBJECT: GRB 230812B: SAO RAS optical observations
DATE:    23/08/16 22:32:47 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin and O. I. Spiridonova (SAO RAS),
report on behalf of the GRB follow-up team.

We observed the field of GRB 230812B (Fermi GBM Team, GCN 34386;
Scotton et al., GCN 34392; Page et al. GCN 34394; Kuin et al.,
GCN 34399; Casentini et al., GCN 34402) with the 1-m telescope
of SAO RAS Zeiss-1000 equipped with the CCD photometer. We obtained
8 x 300 sec. images in Rc band on 19:46:41--20:32:24 UT  (August 17).

The OT (Lesage et al., GCN 34387; Scotton et al., GCN 34392; Page,
GCN 34394; Zheng & Filippenko, GCN 34395; Lipunov et al., GCN 34396;
Salgundi et al., GCN 34397; Ackley et al., GCN 34398; Xiong et al.,
GCN 34401; Casentini et al., GCN 34402; Frederiks et al., GCN 34403;
Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin & Spiridonova,
GCN 34406; Leonini et al., GCN 34408; de Ugarte Postigo et al.,
GCNs 24409, 34410; Belkin et al. GCN 34412; Ruocco et al. GCN 34413;
Frederiks et al. GCN 34414; Ruocco et al. GCN 34415; Shrestha et al.
GCN 34416; Quadri et al. GCN 34417; Adami et al. GCN 34418;
Moretti et al. GCN 34419; Kumar et al. GCN 34420; Belkin et al. GCNs
34421, GCN 34423; Pyshna et al., GCN 34425; Moskvitin & Spiridonova,
GCN 34428; Quadri & Strabla, GCN 34430; Mihov et al., GCN 34431;
Belkin et al. GCN 34432; Klose et al., GCN 34435; Scarfi, GCN 34436;
Moskvitin & Spiridonova, GCN 34442) is clearly detected in our stacked
frame with the brightness of R = 21.46 +/- 0.06 (t_mid - t0 = 4.0496d).

This preliminary photometry is based on the nearby SDSS stars;
magnitudes are converted using Lupton (2005) equations.


GRB_name: GRB230816A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34462
SUBJECT: GRB 230816A: Enhanced Swift-XRT position
DATE:    23/08/17 03:20:23 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 1206 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 230816A, we find an astrometrically corrected X-ray
position (using the XRT-UVOT alignment and matching UVOT field sources
to the USNO-B1 catalogue): RA, Dec = 328.44568, +37.85495 which is equivalent
to:

RA (J2000): 21h 53m 46.96s
Dec (J2000): +37d 51' 17.8"

with an uncertainty of 2.3 arcsec (radius, 90% confidence).

This position may be improved as more data are received. The latest
position can be viewed at http://www.swift.ac.uk/xrt_positions. Position
enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans
et al. (2009, MNRAS, 397, 1177).

This circular was automatically generated, and is an official product of the
Swift-XRT team.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34463
SUBJECT: GRB 230812B: optical photometry from Konkoly
DATE:    23/08/17 10:23:01 GMT
FROM:    Jozsef Vinko at Konkoly Observator <vinko@konkoly.hu>

J. Vinko, L. Kriskovics, A. Pal,  R. Szakats
(Konkoly Observatory, Hungary).

We report detection and photometry of the optical afterglow of GRB230812B (Fermi GBM Team, GCN 34386;
Scotton et al., GCN 34392; Page et al. GCN 34394; Kuin et al.,GCN 34399; Casentini et al., GCN 34402)
with the RC80 robotic telescope at Piszkesteto Station of Konkoly
Observatory taken on 2023-08-13 to 2023-08-15. A series of 300 sec
frames were collected through Sloan r'- and i' bands. The optical afterglow
(Lesage et al., GCN 34387; Scotton et al., GCN 34392; Page,
GCN 34394; Zheng & Filippenko, GCN 34395; Lipunov et al., GCN 34396;
Salgundi et al., GCN 34397; Ackley et al., GCN 34398; Xiong et al.,
GCN 34401; Casentini et al., GCN 34402; Frederiks et al., GCN 34403;
Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin & Spiridonova,
GCN 34406; Leonini et al., GCN 34408; de Ugarte Postigo et al.,
GCNs 24409, 34410; Belkin et al. GCN 34412; Ruocco et al. GCN 34413;
Frederiks et al. GCN 34414; Ruocco et al. GCN 34415; Shrestha et al.
GCN 34416; Quadri et al. GCN 34417; Adami et al. GCN 34418;
Moretti et al. GCN 34419; Kumar et al. GCN 34420; Belkin et al. GCNs
34421, GCN 34423; Pyshna et al., GCN 34425; Moskvitin & Spiridonova,
GCN 34428; Quadri & Strabla, GCN 34430; Mihov et al., GCN 34431;
Belkin et al. GCN 34432; Klose et al., GCN 34435; Scarfi, GCN 34436;
Moskvitin & Spiridonova, GCN 34442, GCN 34461)
was detected on the stacked frames with the following magnitudes, calibrated
via nearby PS1 stars:

Date        UT-middle   t-T0(hr)  Exp(s)   r'(AB-mag)       i'(AB-mag)
2023-08-13  19:41:01    24.71     1500     20.47 (0.10)     19.75 (0.12)
2023-08-14  19:40:32    48.71     1500     21.33 (0.20)     20.51 (0.19)
2023-08-15  21:50:01    74.86     900      >21.89           >21.45

The magnitudes above are not corrected for galactic extinction.


GRB_name: GRB230817A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34464
SUBJECT: GRB 230817A: Fermi GBM Final Real-time Localization
DATE:    23/08/17 12:12:24 GMT
FROM:    Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>

The Fermi GBM team reports the detection of a likely LONG GRB

At 12:02:56 UT on 17 Aug 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230817A (trigger 713966581.55559 / 230817502).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 325.9, Dec = 14.2 (J2000 degrees, equivalent to J2000 21h 43m, 14d 11'), with a statistical uncertainty of 3.3 degrees.

The angle from the Fermi LAT boresight is 93.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230817502/quicklook/glg_skymap_all_bn230817502.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230817502/quicklook/glg_healpix_all_bn230817502.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2023/bn230817502/quicklook/glg_lc_medres34_bn230817502.gif


GRB_name: GRB230817A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34465
SUBJECT: GRB 230817A: BALROG localization (Fermi Trigger 713966581 / GRB 230817502)
DATE:    23/08/17 12:41:57 GMT
FROM:    Jochen Greiner at MPE <jcgrog@mpe.mpg.de>

T. Preis, B. Biltzinger, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
713966581 at 12:02:56 on 17 Aug. 2023 were automatically fitted for spectrum
and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60).

The best-fit position (1 sigma statistical errors) is:
RA(2000.0) = 324.8+/-1.0 deg
Decl.(2000.0) = 17.0+/-0.9 deg
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB230817502/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB230817502/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB230817502/json

                        


GRB_name: GRB230817A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34466
SUBJECT: Fermi GRB 230817A: Global MASTER-Net observations report
DATE:    23/08/17 14:30:32 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>

V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, 
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov,  D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),

R. Podesta, C.Lopez, F. Podesta, C.Francile 
(Observatorio Astronomico Felix Aguilar OAFA),

R. Rebolo, M. Serra 
(The Instituto de Astrofisica de Canarias),

D. Buckley 
(South African Astronomical Observatory),

O.A. Gres, N.M. Budnev
(Irkutsk State University, API),

L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez 
(INAOE, Guillermo Haro Astrophysics Observatory),

A. Tlatov, D. Dormidontov 
(Kislovodsk Solar Station of the Pulkovo Observatory),

A. Gabovich, V.Yurkov 
(Blagoveschensk Educational State University)


MASTER-Tunka robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 230817A ( Fermi GBM team, GCN 34464) errorbox  5213 sec after notice time and 5246 sec after trigger time at 2023-08-17 13:30:22 UT, with upper limit up to  15.9 mag. Observations started at twilight.  The observations began at zenith distance = 59 deg. The sun  altitude  is -9.7 deg. 

The galactic latitude b = -29 deg., longitude l = 70 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=2255349

We obtain a following upper limits.  

Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________

    5254 | 2023-08-17 13:30:22 |        MASTER-Tunka | (21h 48m 35.92s , +12d 10m 22.3s) |   C |    15 | 15.9 |        
Filter C is a clear (unfiltred) band. 


The observation and reduction will continue. 
The message may be cited.


GRB_name: GRB230815A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34467
SUBJECT: GRB 230815A: VLT/HAWK-I near-infrared afterglow detection
DATE:    23/08/17 16:41:24 GMT
FROM:    Benjamin Schneider at MIT <bschn@mit.edu>

B. Schneider (MIT), A. Chrimes (Radboud), D. B. Malesani (Radboud and DAWN/NBI), 
A. J. Levan (Radboud), N. R. Tanvir (U. Leicester), A. de Ugarte Postigo (OCA/CNRS), 
report on behalf of the Stargate collaboration:

We observed the field of GRB 230815A (Klingler et al., GCN 34434; 
Mailyan et al. GCN 34440) with the ESO Very Large Telescope, equipped 
with the HAWK-I near-infrared camera. Observations consisted of two 
epochs of 20 min exposure in the H band at 23:19:53 UT on 2023-08-15 
(~12.5 hr after trigger) and 23:15:46 UT on 2023-08-16 (~36.4 hr after 
trigger).

In both epochs, we clearly detected two sources consistent with the XRT 
error circle (Beardmore et al., GCN 34437). One of the sources has 
significantly faded (~2 mag) between the two epochs, evolving from 
AB mag = 20.11 +/- 0.02 to AB mag = 22.01 +/- 0.08. This corresponds 
to a power-law decay index of 1.65,  similar to the X-ray decay rate, 
suggesting a small host contribution to the NIR flux. The proposed 
afterglow of the burst is detected at coordinates:

RA (J2000) = 12:18:53.24
DEC (J2000) = -58:03:09.45

with an uncertainty of 0.3".

We acknowledge the excellent support provided by the Paranal staff, 
in particular Joe Anderson.


GRB_name: GRB230812B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34468
SUBJECT: GRB 230812B: NOEMA detection
DATE:    23/08/17 18:26:36 GMT
FROM:    Antonio de Ugarte Postigo at OCA <deugarte@oca.eu>

A. de Ugarte Postigo, (OCA-CNRS), J. M. Winters (IRAM), C. C. Thoene (ASU-CAS), S. Antier (OCA), J. F. Agui-Fernandez (IAA-CSIC), M. Bremer (IRAM), D. A. Perley (LJMU), S. Martin (ESO, ALMA) report,

We observed the afterglow of GRB 230812B (Roberts et al. GCN34391, Scotton et al. GCN 34392, Zheng & Filippenko GCN 34395, Beardmore et al. GCN 34400) with NOEMA in the 3mm band. The observation started on August 16 at 13:49 UT (3.79 days after the burst) and included observations at 75 and 89.5 GHz side bands.

The afterglow, previously detected in radio by AMI-LA (Rhodes et al. GCN34433) is weakly detected at 75 GHz with a flux density of 0.14 mJy. At a redshift of z = 0.36 (de Ugarte Postigo et al. GCN 34409) the afterglow currently has a luminosity of <10^30 erg/s/Hz which is amongst the least luminous afterglows detected at these frequencies.


GRB_name: GRB230816A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34469
SUBJECT:  GRB 230816A: Osservatorio Astronomico "Nastro Verde" optical observations
DATE:    23/08/17 19:51:04 GMT
FROM:    Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy - MPC Code C82 <osservatorionastroverde@gmail.com>

Nello Ruocco at Osservatorio Nastro Verde - Sorrento (Naples) - Italy
in a large collaboration with:
M.G. Dainotti (National Astronomical Observatory of Japan), 
Y. Niino (Tokyo University, Institute of Astronomy), 
K. Kalinowski (Aarhus University, Department of Physics and Astronomy),
B. De Simone (Universita' degli Studi Di Salerno)
report: 

We observed the field of GRB 230816A (Siegel et al., GCN 34450) with telescope of Nastro Verde Observatory - Sorrento (Naples), Italy.
Member of: 
AAVSO - American Association of Variable Star Observers.
UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili.
AstroCampania Associazione

The observations started at 18:55 UT of 2023/08/16, after about 2,45 hours after the GRB trigger, at the end of twilight with clear skies, with principal telescope  SC 0.35 f/10 with focal reduced + CCD Sbig ST10 XME
I took 25 image of 240 sec each. All images are unfiltered, calibrated with masterdark and masterflat,stacked with Tycho Tracker software
We have detected a faint  source of magnitude 19.1 G at the enhanced position reported by Swift-XRT (Siegel et al., GCN 34450, P.A. Evans et al., GCN 34462) and by optical telescopes ( A. S. Moskvitin et al GCN 34456., N. Pankov et al GCN 34457., Mohammad Odeh et al GCN 34458., S. Klose et al GCN 34459., R. Kumar et al GCN 34460)
at following position

RA      (J2000)  21h 53m 46.87s 
Decl.   (J2000) +37Â° 51' 14.7"  

Photometry and astrometry on stack of 13 images each of 240 sec

GRB 230816A KC2023 08 16.88481 21 53 46.87 +37 51 14.7          19.1 G      C82    
 



Magnitudes were estimated with the GAIA DR2 cat. and 
are not corrected for galactic dust extinction.



The message may be cited.


GRB_name: GRB230816A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34470
SUBJECT: GRB 230816A: Swift-XRT refined Analysis
DATE:    23/08/17 21:21:12 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

M.G. Bernardini (INAF-OAB), J. D. Gropp (PSU), S. Dichiara (PSU), J.A.
Kennea (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester),
E. Ambrosi  (INAF-IASFPA) , M. Capalbi (INAF-IASFPA) and P.A. Evans
report on behalf of the Swift-XRT team:

We have analysed 3.9 ks of XRT data for GRB 230816A, from 97 s to 91.3
ks after the  BAT trigger. The data are entirely in Photon Counting
(PC) mode. 

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.44 (+0.27, -0.43).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.66 (+0.31, -0.14). The
best-fitting absorption column is  consistent with the Galactic value
of 2.9 x 10^21 cm^-2 (Willingale et al. 2013). The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum  is 4.4 x 10^-11 (5.6 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.9 (+/-1.2) x 10^21 cm^-2
Galactic foreground: 2.9 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.66 (+0.31, -0.14)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/01185673.

This circular is an official product of the Swift-XRT team.


GRB_name: GRB230812B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34471
SUBJECT: GRB 230812B: SAO RAS optical observations
DATE:    23/08/17 23:46:52 GMT
FROM:    Moskvitin Alexander at SAO RAS <mosk@sao.ru>

A. S. Moskvitin and O. I. Spiridonova (SAO RAS),
report on behalf of the GRB follow-up team.

We observed the field of GRB 230812B (Fermi GBM Team, GCN 34386;
Scotton et al., GCN 34392; Page et al. GCN 34394; Kuin et al.,
GCN 34399; Casentini et al., GCN 34402) with the 1-m telescope
of SAO RAS Zeiss-1000 equipped with the CCD photometer. We obtained
12 x 300 sec. images in Rc band on 21:14:58--22:26:52 UT (August 17).
In the previous GCN 34461 we have a typo in date, the correct date is
August 16. We apologize for the possible confusion and inconvenience.

The OT (Lesage et al., GCN 34387; Scotton et al., GCN 34392; Page,
GCN 34394; Zheng & Filippenko, GCN 34395; Lipunov et al., GCN 34396;
Salgundi et al., GCN 34397; Ackley et al., GCN 34398; Xiong et al.,
GCN 34401; Casentini et al., GCN 34402; Frederiks et al., GCN 34403;
Mao et al., GCN 34404; Odeh et al., GCN 34405; Moskvitin & Spiridonova,
GCN 34406; Leonini et al., GCN 34408; de Ugarte Postigo et al.,
GCNs 24409, 34410; Belkin et al. GCN 34412; Ruocco et al. GCN 34413;
Frederiks et al. GCN 34414; Ruocco et al. GCN 34415; Shrestha et al.
GCN 34416; Quadri et al. GCN 34417; Adami et al. GCN 34418;
Moretti et al. GCN 34419; Kumar et al. GCN 34420; Belkin et al. GCNs
34421, GCN 34423; Pyshna et al., GCN 34425; Moskvitin & Spiridonova,
GCN 34428; Quadri & Strabla, GCN 34430; Mihov et al., GCN 34431;
Belkin et al. GCN 34432; Klose et al., GCN 34435; Scarfi, GCN 34436;
Moskvitin & Spiridonova, GCNs 34442, 34461; Vinko et al., GCN 34463)
is clearly detected in our stacked frame with the brightness of
R = 21.79 +/- 0.09 (t_mid - t0 = 5.1199 days).

This preliminary photometry is based on the nearby SDSS stars;
magnitudes are converted using Lupton (2005) equations.

We are grateful to the SAO RAS staff for their technical support.


GRB_name: GRB230817A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  34472
SUBJECT: GRB 230817A: AstroSat CZTI detection
DATE:    23/08/18 05:55:19 GMT
FROM:    Gaurav Waratkar at IIT Bombay <gauravwaratkar@iitb.ac.in>

P. K. Navaneeth (IUCAA), B. Pari (IITB), G. Waratkar (IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long GRB 230817A which was also detected by Fermi (Fermi GBM Team, GCN Circ. 34464).

The source was clearly detected in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2023-08-17 12:03:31.50 UTC. The measured peak count rate associated with the burst is 470 (+48, -40) counts/s above the background in the combined data of all quadrants, with a total of 7321 (+420, -529) counts. The local mean background count rate was 418 (+2, -2) counts/s. Using cumulative rates, we measure a T90 of 48 (+6, -7) s. In the preliminary analysis, we find 537 Compton events associated with this event.

The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2023-08-17 12:03:31.31 UTC. The measured peak count rate associated with the burst is 361 (+80, -24) counts/s above the background in the combined data of all quadrants, with a total of 4084 (+1006, -1452) counts. The local mean background count rate was 1322 (+5, -4) counts/s. We measure a T90 of 33 (+9, -5) s from the cumulative Veto light curve.

CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.

CZTI GRB detections are reported regularly on the payload site at: 
http://astrosat.iucaa.in/czti/?q=grb


