# GCN_circulars

GRB_name: GRB200420A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27608
SUBJECT: Fermi GRB 200420A: Global MASTER-Net observations report 
DATE:    20/04/20 03:15:07 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

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




MASTER-IAC robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 200420A ( Fermi GBM team, GCN 27607) errorbox  46 sec after notice time and 74 sec after trigger time at 2020-04-20 02:34:13 UT, with upper limit up to  17.5 mag. The observations began at zenith distance = 67 deg. The sun  altitude  is -44.6 deg. 

MASTER-SAAO robotic telescope  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 200420A errorbox  49 sec after notice time and 77 sec after trigger time at 2020-04-20 02:34:16 UT, with upper limit up to  18.1 mag. The observations began at zenith distance = 43 deg. The sun  altitude  is -32.2 deg. 

The galactic latitude b = -12 deg., longitude l = 40 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1340649

We obtain a following upper limits.  

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

      80 | 2020-04-20 02:34:13 |          MASTER-IAC | (19h 42m 48.61s , +00d 48m 51.8s) |  P- |    10 | 15.7 |        
     110 | 2020-04-20 02:34:13 |          MASTER-IAC | (19h 42m 48.61s , +00d 48m 51.7s) |  P- |    70 | 17.0 |  Coadd 
      80 | 2020-04-20 02:34:13 |          MASTER-IAC | (19h 43m 29.91s , +00d 45m 12.3s) |  P| |    10 | 15.2 |        
     120 | 2020-04-20 02:34:13 |          MASTER-IAC | (19h 43m 29.90s , +00d 45m 12.3s) |  P| |    90 | 16.7 |  Coadd 
      88 | 2020-04-20 02:34:16 |         MASTER-SAAO | (19h 46m 31.66s , +00d 48m 44.4s) |   C |    20 | 17.4 |        
      93 | 2020-04-20 02:34:21 |         MASTER-SAAO | (19h 39m 30.51s , +00d 47m 31.7s) |   C |    20 | 17.8 |        
     127 | 2020-04-20 02:34:55 |         MASTER-SAAO | (19h 46m 33.59s , +00d 49m 44.6s) |   C |    20 | 17.4 |        
     133 | 2020-04-20 02:35:01 |         MASTER-SAAO | (19h 39m 32.42s , +00d 48m 31.9s) |   C |    20 | 17.6 |        
     150 | 2020-04-20 02:35:18 |          MASTER-IAC | (19h 43m 37.22s , +00d 45m 15.2s) |  P| |    20 | 15.8 |        
     150 | 2020-04-20 02:35:18 |          MASTER-IAC | (19h 42m 56.01s , +00d 48m 54.9s) |  P- |    20 | 16.3 |        
     181 | 2020-04-20 02:35:44 |         MASTER-SAAO | (19h 46m 39.17s , +00d 48m 44.4s) |   C |    30 | 17.6 |        
     186 | 2020-04-20 02:35:49 |         MASTER-SAAO | (19h 39m 37.98s , +00d 47m 31.8s) |   C |    30 | 17.8 |        
     238 | 2020-04-20 02:36:37 |          MASTER-IAC | (19h 42m 52.91s , +00d 50m 24.8s) |  P- |    40 | 16.7 |        
     268 | 2020-04-20 02:37:01 |         MASTER-SAAO | (19h 46m 32.95s , +00d 47m 42.0s) |   C |    50 | 17.6 |        
     273 | 2020-04-20 02:37:06 |         MASTER-SAAO | (19h 39m 31.73s , +00d 46m 29.2s) |   C |    50 | 17.9 |        
     342 | 2020-04-20 02:38:10 |         MASTER-SAAO | (19h 46m 40.30s , +00d 47m 44.0s) |   C |    60 | 17.8 |        
     347 | 2020-04-20 02:38:16 |         MASTER-SAAO | (19h 39m 39.07s , +00d 46m 31.2s) |   C |    60 | 18.0 |        
     350 | 2020-04-20 02:38:19 |          MASTER-IAC | (19h 43m 34.18s , +00d 45m 39.9s) |  P| |    60 | 16.7 |        
     350 | 2020-04-20 02:38:19 |          MASTER-IAC | (19h 42m 53.02s , +00d 49m 19.9s) |  P- |    60 | 17.0 |        
     444 | 2020-04-20 02:39:52 |         MASTER-SAAO | (19h 46m 08.52s , +00d 01m 02.6s) |   C |    60 | 17.8 |        
     450 | 2020-04-20 02:39:58 |         MASTER-SAAO | (19h 39m 07.28s , -00d 00m 10.0s) |   C |    60 | 18.0 |        
     469 | 2020-04-20 02:40:18 |          MASTER-IAC | (19h 47m 28.32s , +01d 58m 26.6s) |   C |    60 | 17.2 |        
     469 | 2020-04-20 02:40:18 |          MASTER-IAC | (19h 39m 25.03s , +02d 02m 56.4s) |   C |    60 | 17.4 |        
     539 | 2020-04-20 02:41:27 |         MASTER-SAAO | (19h 46m 51.96s , -02d 00m 27.7s) |   C |    60 | 17.5 |        
     544 | 2020-04-20 02:41:32 |         MASTER-SAAO | (19h 39m 50.40s , -02d 01m 40.2s) |   C |    60 | 17.6 |        
     587 | 2020-04-20 02:42:16 |          MASTER-IAC | (19h 49m 33.53s , +03d 57m 42.2s) |   C |    60 | 17.3 |        
     587 | 2020-04-20 02:42:16 |          MASTER-IAC | (19h 41m 29.36s , +04d 02m 12.3s) |   C |    60 | 17.4 |        
     641 | 2020-04-20 02:43:09 |         MASTER-SAAO | (20h 02m 10.02s , +00d 01m 19.3s) |   C |    60 | 17.9 |        
     647 | 2020-04-20 02:43:15 |         MASTER-SAAO | (19h 55m 08.85s , +00d 00m 06.4s) |   C |    60 | 18.1 |        
     706 | 2020-04-20 02:44:14 |          MASTER-IAC | (19h 55m 19.28s , +02d 02m 49.7s) |   C |    60 | 17.5 |        
     706 | 2020-04-20 02:44:14 |          MASTER-IAC | (20h 03m 22.51s , +01d 58m 18.6s) |   C |    60 | 17.0 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200420A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27609
SUBJECT: GRB 200420: Fermi GBM Final Localization Correction
DATE:    20/04/20 09:15:33 GMT
FROM:    Andreas von Kienlin at MPE  <azk@mpe.mpg.de>

C. Malacaria (NASA-MSFC/USRA) reports on behalf of the Fermi GBM Team:

"
At 02:32:58.60 UT on 20 Apr 2020, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 200420 (trigger 609042783 / 200420106).

The on-ground calculated location, using the Fermi GBM trigger data, is RA =
304.6, Dec = -20.3
(J2000 degrees, equivalent to J2000 20h 18m, -20d 16'), with a statistical
uncertainty of 27.3 degrees.
The angle from the Fermi LAT boresight is 11.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200420106/q
uicklook/glg_skymap_all_bn200420106.png

The HEALPix FITS file, including the estimated localization systematic, can
be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200420106/q
uicklook/glg_healpix_all_bn200420106.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200420106/q
uicklook/glg_lc_medres34_bn200420106.gif
"


GRB_name: GRB200412B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27610
SUBJECT: GRB 200412B: continued Mondy and Terskol optical observations
DATE:    20/04/20 19:47:32 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), A. Pozanenko (IKI), A.V. Shein (INASAN), I.A. Izvekova 
(ICAMER NASU), E. Klunko (ISTP),  M. Eselevich (ISTP), E. Mazaeva (IKI), 
A. Volnova  (IKI) report on behalf of GRB IKI FuN:

We observed the field of GRB 200412B (Fermi GBM team, GCN 27547; Mailyan
et al., GCN 27558; see also Burgess et al., GCN 27548; Longo et al., GCN
27557; Page et al., GCN 27561; Gupta et al., GCN 27563; Zheng et al., 
GCN 27565)  with  AZT-33IK 1.5-m telescope of Sayan observatory (Mondy) 
and Zeiss-2000 of Mt.Terskol observatory.  We  detected  the afterglow 
of GRB 200412B  (Lipunov et al., GCNs 27555, 27556; see also e.g. Kumar 
et al., GCN 27564; Belkin et al., GCN 27566, Stecklum et al., GCN 27567, 
Moskvitin GCN 27570; Xin  et al., GCN 27571).  Preliminary photometry of 
the afterglow is following.

Date       UT start  t-T0       Filter  OT Err. UL   Observatory
                     (mid, days)
2020-04-19 16:10:31 7.32142 41*120 R 23.50 0.30 23.6 Mondy AZT-33IK
2020-04-19 22:23:48 7.59245 48*120 R 23.55 0.28 23.7 Terskol Z-2000

The photometry is based on nearby USNO-B1.0 stars.
The updated light curve can be found at 
http://grb.rssi.ru/GRB200412B/GRB200412B_LC.png


GRB_name: GRB200421A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27616
SUBJECT: GRB 200421A: Fermi GBM Final Real-time Localization
DATE:    20/04/21 20:56:21 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 LONG GRB

At 20:45:59 UT on 21 Apr 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200421A (trigger 609194764.72639 / 200421865).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 164.0, Dec = 63.8 (J2000 degrees, equivalent to J2000 10h 56m, 63d 47'), with a statistical uncertainty of 2.3 degrees.

The angle from the Fermi LAT boresight is 14.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200421865/quicklook/glg_skymap_all_bn200421865.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200421865/quicklook/glg_healpix_all_bn200421865.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200421865/quicklook/glg_lc_medres34_bn200421865.gif


GRB_name: GRB200421A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27618
SUBJECT: Fermi GRB 200421A: Global MASTER-Net observations report 
DATE:    20/04/21 23:30:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200421A ( Fermi GBM team, GCN 27616) errorbox  48 sec after notice time and 75 sec after trigger time at 2020-04-21 20:47:15 UT, with upper limit up to  20.4 mag. The observations began at zenith distance = 30 deg. The sun  altitude  is -32.5 deg. 

MASTER-IAC robotic telescope  located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 200421A errorbox  548 sec after notice time and 575 sec after trigger time at 2020-04-21 20:55:35 UT, with upper limit up to  19.5 mag. The observations began at zenith distance = 37 deg. The sun  altitude  is -18.3 deg. 

The galactic latitude b = 49 deg., longitude l = 142 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1342104

We obtain a following upper limits.  

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

      86 | 2020-04-21 20:47:15 |      MASTER-Tavrida | (10h 27m 01.45s , +63d 21m 13.8s) |   C |    20 | 18.5 |        
     111 | 2020-04-21 20:47:15 |      MASTER-Tavrida | (10h 27m 01.45s , +63d 21m 13.8s) |   C |    70 | 19.4 |  Coadd 
     126 | 2020-04-21 20:47:55 |      MASTER-Tavrida | (10h 27m 05.58s , +63d 22m 60.0s) |   C |    20 | 18.5 |        
     172 | 2020-04-21 20:48:36 |      MASTER-Tavrida | (10h 26m 57.61s , +63d 22m 04.3s) |   C |    30 | 18.9 |        
     227 | 2020-04-21 20:49:26 |      MASTER-Tavrida | (10h 26m 58.60s , +63d 23m 04.7s) |   C |    40 | 19.1 |        
     287 | 2020-04-21 20:49:26 |      MASTER-Tavrida | (10h 26m 58.61s , +63d 23m 04.8s) |   C |   160 | 20.1 |  Coadd 
     292 | 2020-04-21 20:50:27 |      MASTER-Tavrida | (10h 27m 03.30s , +63d 22m 04.8s) |   C |    50 | 19.3 |        
     372 | 2020-04-21 20:51:37 |      MASTER-Tavrida | (10h 26m 57.52s , +63d 21m 04.7s) |   C |    70 | 19.4 |        
     458 | 2020-04-21 20:53:07 |      MASTER-Tavrida | (10h 20m 09.48s , +64d 11m 08.1s) |   C |    60 | 19.4 |        
     538 | 2020-04-21 20:54:28 |      MASTER-Tavrida | (10h 29m 11.17s , +66d 11m 39.8s) |   C |    60 | 19.4 |        
     636 | 2020-04-21 20:55:35 |          MASTER-IAC | (10h 55m 15.49s , +63d 58m 18.2s) |  P| |   120 | 18.7 |        
     796 | 2020-04-21 20:55:35 |          MASTER-IAC | (10h 55m 15.49s , +63d 58m 18.2s) |  P| |   440 | 19.5 |  Coadd 
     636 | 2020-04-21 20:55:35 |          MASTER-IAC | (10h 53m 42.39s , +64d 02m 08.5s) |  P- |   120 | 18.6 |        
     796 | 2020-04-21 20:55:35 |          MASTER-IAC | (10h 53m 42.40s , +64d 02m 08.5s) |  P- |   440 | 19.3 |  Coadd 
     649 | 2020-04-21 20:55:48 |      MASTER-Tavrida | (11h 04m 51.95s , +64d 00m 51.3s) |   C |   120 | 19.9 |        
     809 | 2020-04-21 20:55:48 |      MASTER-Tavrida | (11h 04m 51.95s , +64d 00m 51.3s) |   C |   440 | 20.4 |  Coadd 
     799 | 2020-04-21 20:58:08 |      MASTER-Tavrida | (11h 04m 53.31s , +64d 01m 51.7s) |   C |   140 | 19.9 |        
     822 | 2020-04-21 20:58:31 |          MASTER-IAC | (10h 53m 34.48s , +64d 01m 32.8s) |  P- |   140 | 18.6 |        
     822 | 2020-04-21 20:58:31 |          MASTER-IAC | (10h 55m 07.45s , +63d 57m 41.8s) |  P| |   140 | 18.8 |        
     980 | 2020-04-21 21:00:49 |      MASTER-Tavrida | (11h 04m 58.03s , +64d 00m 51.9s) |   C |   180 | 19.9 |        
    1041 | 2020-04-21 21:01:51 |          MASTER-IAC | (10h 55m 08.43s , +63d 58m 41.6s) |  P| |   180 | 19.0 |        
    1180 | 2020-04-21 21:04:10 |      MASTER-Tavrida | (11h 04m 51.51s , +63d 59m 51.9s) |   C |   180 | 20.0 |        
    1249 | 2020-04-21 21:05:18 |          MASTER-IAC | (10h 55m 14.12s , +63d 57m 41.0s) |  P| |   180 | 19.0 |        
    1249 | 2020-04-21 21:05:18 |          MASTER-IAC | (10h 53m 40.98s , +64d 01m 31.9s) |  P- |   180 | 18.7 |        
    2125 | 2020-04-21 21:20:54 |      MASTER-Tavrida | (10h 20m 07.10s , +64d 10m 36.5s) |   C |    60 | 19.4 |        
    2206 | 2020-04-21 21:22:15 |      MASTER-Tavrida | (10h 38m 25.64s , +64d 11m 49.7s) |   C |    60 | 19.3 |        
    2286 | 2020-04-21 21:23:36 |      MASTER-Tavrida | (10h 29m 12.61s , +66d 10m 45.5s) |   C |    60 | 19.4 |        
    2367 | 2020-04-21 21:24:56 |      MASTER-Tavrida | (10h 48m 50.67s , +66d 09m 58.5s) |   C |    60 | 19.4 |        
    2447 | 2020-04-21 21:26:16 |      MASTER-Tavrida | (10h 56m 47.88s , +64d 11m 45.0s) |   C |    60 | 19.4 |        
    2930 | 2020-04-21 21:34:19 |      MASTER-Tavrida | (10h 38m 24.85s , +64d 10m 50.0s) |   C |    60 | 19.3 |        
    3010 | 2020-04-21 21:35:39 |      MASTER-Tavrida | (10h 48m 50.84s , +66d 11m 59.2s) |   C |    60 | 19.3 |        
    3090 | 2020-04-21 21:36:59 |      MASTER-Tavrida | (10h 56m 50.75s , +64d 10m 60.0s) |   C |    60 | 19.4 |        
    3121 | 2020-04-21 21:37:30 |          MASTER-IAC | (10h 37m 09.03s , +62d 09m 29.6s) |   C |    60 | 18.5 |        
    3121 | 2020-04-21 21:37:30 |          MASTER-IAC | (10h 54m 32.50s , +62d 04m 53.2s) |   C |    60 | 18.6 |        
    3171 | 2020-04-21 21:38:20 |      MASTER-Tavrida | (11h 15m 03.11s , +64d 10m 07.5s) |   C |    60 | 19.2 |        
    3246 | 2020-04-21 21:39:35 |          MASTER-IAC | (10h 57m 10.05s , +66d 09m 45.2s) |   C |    60 | 18.6 |        
    3246 | 2020-04-21 21:39:35 |          MASTER-IAC | (11h 17m 14.87s , +66d 05m 01.4s) |   C |    60 | 18.6 |        
    3251 | 2020-04-21 21:39:40 |      MASTER-Tavrida | (11h 21m 28.36s , +62d 11m 55.1s) |   C |    60 | 19.0 |        
    3331 | 2020-04-21 21:41:01 |      MASTER-Tavrida | (11h 33m 28.87s , +64d 12m 03.1s) |   C |    60 | 19.2 |        
    3366 | 2020-04-21 21:41:35 |          MASTER-IAC | (11h 02m 17.17s , +60d 11m 59.9s) |   C |    60 | 18.3 |        
    3412 | 2020-04-21 21:42:21 |      MASTER-Tavrida | (10h 39m 35.72s , +60d 11m 41.9s) |   C |    60 | 18.8 |        
    3490 | 2020-04-21 21:43:39 |          MASTER-IAC | (10h 37m 11.63s , +62d 09m 50.5s) |   C |    60 | 18.6 |        
    3490 | 2020-04-21 21:43:39 |          MASTER-IAC | (10h 54m 35.39s , +62d 05m 11.9s) |   C |    60 | 18.8 |        
    3492 | 2020-04-21 21:43:41 |      MASTER-Tavrida | (11h 15m 10.34s , +64d 11m 06.1s) |   C |    60 | 19.2 |        
    3572 | 2020-04-21 21:45:02 |      MASTER-Tavrida | (11h 21m 24.55s , +62d 10m 05.1s) |   C |    60 | 19.1 |        
    3611 | 2020-04-21 21:45:40 |          MASTER-IAC | (11h 17m 14.08s , +66d 06m 38.0s) |   C |    60 | 18.5 |        
    3611 | 2020-04-21 21:45:40 |          MASTER-IAC | (10h 57m 07.85s , +66d 11m 22.5s) |   C |    60 | 18.5 |        
    3733 | 2020-04-21 21:47:42 |      MASTER-Tavrida | (11h 33m 26.04s , +64d 11m 52.1s) |   C |    60 | 19.3 |        
    3893 | 2020-04-21 21:50:23 |      MASTER-Tavrida | (10h 39m 41.31s , +60d 11m 11.5s) |   C |    60 | 19.1 |        
    3974 | 2020-04-21 21:51:43 |      MASTER-Tavrida | (10h 55m 38.78s , +60d 10m 49.8s) |   C |    60 | 19.2 |        
    4296 | 2020-04-21 21:57:05 |      MASTER-Tavrida | (10h 55m 41.75s , +60d 11m 32.5s) |   C |    60 | 19.2 |        
    4617 | 2020-04-21 22:02:26 |      MASTER-Tavrida | (10h 30m 05.72s , +62d 09m 26.1s) |   C |    60 | 19.1 |        
    5019 | 2020-04-21 22:09:08 |      MASTER-Tavrida | (10h 30m 05.66s , +62d 10m 23.8s) |   C |    60 | 19.1 |        
    7164 | 2020-04-21 22:44:53 |      MASTER-Tavrida | (10h 47m 09.38s , +62d 11m 33.3s) |   C |    60 | 18.9 |        
    7341 | 2020-04-21 22:47:50 |      MASTER-Tavrida | (11h 08m 38.99s , +66d 10m 25.9s) |   C |    60 | 19.0 |        
    7422 | 2020-04-21 22:49:11 |      MASTER-Tavrida | (11h 11m 43.05s , +60d 10m 03.3s) |   C |    60 | 18.9 |        
    7502 | 2020-04-21 22:50:31 |      MASTER-Tavrida | (10h 47m 16.18s , +62d 10m 58.4s) |   C |    60 | 19.1 |        
    7583 | 2020-04-21 22:51:52 |      MASTER-Tavrida | (11h 04m 16.48s , +62d 10m 38.2s) |   C |    60 | 19.1 |        
    7663 | 2020-04-21 22:53:12 |      MASTER-Tavrida | (11h 08m 33.22s , +66d 11m 44.3s) |   C |    60 | 19.1 |        
    7744 | 2020-04-21 22:54:33 |      MASTER-Tavrida | (11h 28m 25.22s , +66d 11m 00.6s) |   C |    60 | 19.0 |        
    7824 | 2020-04-21 22:55:54 |      MASTER-Tavrida | (11h 11m 39.42s , +60d 09m 39.3s) |   C |    60 | 19.0 |        
    7985 | 2020-04-21 22:58:34 |      MASTER-Tavrida | (11h 04m 19.01s , +62d 11m 03.3s) |   C |    60 | 19.0 |        
    8066 | 2020-04-21 22:59:55 |      MASTER-Tavrida | (11h 28m 21.20s , +66d 10m 09.3s) |   C |    60 | 19.1 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200410A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27621
SUBJECT: GRB 200410A: Liverpool Telescope First Hour Observations
DATE:    20/04/22 11:40:04 GMT
FROM:    Iain Steele at Liverpool/JMU  <i.a.steele@ljmu.ac.uk>

I.A. Steele, M. Shrestha, S. Kobayashi (Liverpool JMU), C. Mundell (Univ. Bath), A. Gomboc (Univ. Nova Gorica) report on behalf of a wider collaboration:

We observed the field of Swift GRB 200410A (GCN 27518) with the 2.0m Liverpool Telescope, La Palma on 2020 Apr 10 starting at 02:28:38 UT using the IOO optical camera for a period of ~1 hour in the râ€™ and Iâ€™ bands. The target was well resolved from the two nearby stars.  Data was calibrated with respect to APASS secondary standard stars in the images.

We confirm the optical counterpart reported by Swift UVOT and Ondrejov (GCN 27520).

At T=155 seconds after the BAT trigger time, we measure râ€™ = 18.2.

Both the râ€™ and iâ€™ band light curves subsequently show a power law decay in flux vs time with alpha = 0.7 over the first hour.



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GRB_name: GRB200415A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27622
SUBJECT: GRB 200415A: ASIM observation
DATE:    20/04/22 12:39:03 GMT
FROM:    Martino Marisaldi at U of Bergen, Norway  <martino.marisaldi@uib.no>

M. Marisaldi (University of Bergen), A. Mezentsev (University of Bergen), 
N. Ã˜stgaard (University of Bergen), V. Reglero (University of Valencia) 
and T. Neubert (DTU Space) report on behalf of the ASIM Team:

At 08:48:05.557 UT on 15 April 2020, the Atmosphere-Space Interactions Monitor (ASIM)
mission triggered on the very bright GRB 200415A (GCN Circ. 27579, 27580, 
27585, 27586, 27587, 27590, 27595, 27596, 27597, 27599).
Photon by photon data with <1 microsecond time resolution have been
collected for a time interval of two seconds centered at the trigger time.

As seen by the Modular X- and Gamma-Ray Sensor (MXGS) onboard ASIM
the burst consists of a bright peak about 6 ms in duration, followed by a steadily
decaying tail at least 200 ms long. The emission is detected in both 
the MXGS Low Energy Detector (LED), sensitive in the range 0.05 to 0.4 MeV,
and in the High Energy Detector (HED), sensitive in the range 0.3 to >30 MeV. 
Significant emission is observed up to several MeV. 
Further data analysis is ongoing and will be published elsewhere.

ASIM is an ESA mission onboard the International Space Station dedicated to the 
observation of Terrestrial Gamma-ray Flashes (TGFs) and Transient Luminous Events (TLEs) 
operative since June 2018 (Neubert et al., Space Sci Rev (2019) 215:26 
https://doi.org/10.1007/s11214-019-0592-z ). 
The payload includes the Modular X- and Gamma-Ray Sensor (MXGS) 
(Ã˜stgaard et al., Space Sci Rev (2019) 215:23 https://doi.org/10.1007/s11214-018-0573-7 ), 
and the the Modular Multispectral Imaging Array  (MMIA) 
(Chanrion et al., Space Sci Rev (2019) 215:28 https://doi.org/10.1007/s11214-019-0593-y ). 
The ASIM Science Data Centre (ASDC) website is https://asdc.space.dtu.dk/


GRB_name: GRB200422A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27626
SUBJECT: IPN triangulation of GRB 200422A (long/very bright)
DATE:    20/04/22 21:02:48 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

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

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

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

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

The long-duration, very bright GRB 200422A
has been detected by Konus-Wind, INTEGRAL (SPI-ACS), Mars-Odyssey 
(HEND), and Swift (BAT), so far, at about 26536 s UT (07:22:16).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   196.399 (13h 05m 36s) -20.245 (-20d 14' 41")
  Corners:
   195.143 (13h 00m 34s) -22.037 (-22d 02' 12")
   195.441 (13h 01m 46s) -22.030 (-22d 01' 48")
   197.651 (13h 10m 36s) -18.334 (-18d 20' 02")
   197.341 (13h 09m 22s) -18.387 (-18d 23' 14")
  ---------------------------------------------
The error box area is 3548 sq. arcmin, and its maximum
dimension is 4.4 deg (the minimum one is 14 arcmin).
The Sun distance was about 162 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB200422_T26537/IPN

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


GRB_name: GRB200415A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27627
SUBJECT: GRB 200415A (possible magnetar Giant Flare in Sculptor Galaxy): INTEGRAL observations
DATE:    20/04/22 22:33:18 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), P. Minaev (IKI), I. Chelovekov (IKI), S. Grebenev 
(IKI) report on behalf of GRB IKI FuN:

We analysed publicly available INTEGRAL data around the time of GRB 
200415A (Fermi GBM team, GCN 27579; Omodei et al., GCN 27586; Frederiks 
et al., GCN 27596; Marisaldi et al., GCN 27622).  Direction to GRB 
200415A localization  by IPN (Svinkin et al., GCN 27585) and Fermi LAT 
(Omodei et al., GCN 27597) is 89 degrees off-axis for INTEGRAL 
telescopes, which is nearly optimal for the SPI-ACS detector. This event 
did not trigger IBAS (see 
http://www.isdc.unige.ch/integral/science/grb#ACS).

The GRB 200415A is clearly visible in SPI-ACS, IBIS/ISGRI and 
IBIS/PICsIT (for latter two - outside the FoV). Using IBIS/ISGRI we 
derived the GRB 200415A time interval from T0+0.38 up to T0+0.52, where 
T0 = 2020-04-15T08:48:05.56  (UT) is the trigger time of GRB Fermi.

Duration of GRB 200415A is 0.20 s as seen in SPI-ACS and 0.14 c in 
IBIS/ISGRI in 30-500 keV energy band. The fluence of the event in 
SPI-ACS is 27800 +/- 300 cts, which is equivalent to 6.7Ðµ-6 ergs/cm2 in 
10-1000 keV energy (1.2Ðµ-6 -- 3.8Ðµ-5 ergs/cm2 is the 95% confident 
region using calibration of SPI-ACS for short Pozanenko et al., 
Astronomy Letters, 45, 11, 710 (2019). The fluence of the event in ISGRI 
is  3.2 +/- 2.2e-6 ergs/cm2 (30-100 keV) and  3.7 +/- 2.4e-6 ergs/cm2 
(100-500 keV) after calibration of ISGRI (Chelovekov et al., Astronomy 
Letters, 45, 10, 635 (2019).
We detected neither any precursor within 200 s prior the trigger, nor 
significant extended emission up to +100 s.

Light curves of the GRB 200415A registered by INTEGRAL detectors can be 
found at
http://grb.rssi.ru/GRB200415A_ISGRI_PICSIT_ACS.png

We note a possible multi-pulse structure of the event as can be seen in 
the IBIS/ISGRI light curve.

We also put the spectral data reported  (Bissaldi et al., GCN 27587; 
Frederiks et al., GCN 27596) onto E_iso -- E_p diagram (AKA Amati 
relation) and EHD diagram (Minaev et al., MNRAS, 492, 1919 (2020).

If GRB 200415A is a real gamma-ray burst its redshift should be z > 0.03 
as it is seen from the event trajectory in the diagrams.

We put the Giant Flare (GF) of SGR 1806-20 on 2004-12-27 on the E_iso -- 
E_p diagram and found that position of GRB 200415A, if its source in 
Sculptor galaxy (NGC 253) at 3.5 Mpc,  is compatible with the position 
of the GF of SGR 1806-20 on 2004-12-27 (see Figures below).

E_iso -- E_p diagram (AKA Amati relation) and EHD diagram can be found at
http://grb.rssi.ru/GRB200415A/GRB200415A_Amati_SGR.png
http://grb.rssi.ru/GRB200415A/GRB200415A_EHD_SGR.png


GRB_name: GRB200422A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27628
SUBJECT: GRB 200422A: MASTER optical observations
DATE:    20/04/22 22:52:54 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov (Lomonosov MSU), D.Svinkin (Ioffe Institute), E. Gorbovskoy, 
V.Kornilov, P.Balanutsa,A.Kuznetsov,F.Balakin,V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov, V.Shumkov, N.Tiurina (Lomonosov Moscow State University, SAI, Physics Department),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
R. Podesta, C.Lopez, F. Podesta, C.Francile(Observatorio Astronomico Felix Aguilar OAFA),
H. Levato(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),
R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias),
D. Buckley(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API),
V. Yurkov, A. Gabovich, Yu. Sergienko(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 long bright IPN GRB200422A (Hurley et al., GCN 27626, Ttrig=3030-04-22 07:22:16)
at 2020-04-22 19:45:16UT with mlim~20.5.

The observations began at zenith distance = 59 deg. The sun  altitude was -45 deg.

Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/ligo_1.php?id=11505


GRB_name: GRB200415A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27629
SUBJECT: GRB 200415A correction to GCN 27627 (possible magnetar Giant Flare in Sculptor Galaxy): INTEGRAL observations
DATE:    20/04/23 08:21:58 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Pozanenko (IKI), P. Minaev (IKI), I. Chelovekov (IKI), S. Grebenev 
(IKI) report on behalf of GRB IKI FuN:

The correct URL for light curves of GRB 200415A registered by INTEGRAL 
detectors can be found at
http://grb.rssi.ru/GRB200415A/GRB200415A_ISGRI_PICSIT_ACS.png


We apologize for inconvenience.


GRB_name: GRB200422A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27630
SUBJECT: GRB 200422A: AstroSat CZTI detection
DATE:    20/04/23 09:23:31 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma, A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200422A, which was also detected by  IPN (Hurley K. et al., GCN #27626) and Global MASTER-Net (Lipunov V. et al., GCN #27628).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 2020-04-22 07:22:15.088 UT. The measured peak count rate associated with the burst is 2864 +/- 56 cts/s above the background in the combined data of four quadrants, with a total of 29362 +/- 55 cts. The local mean background count rate was 566 +/- 2 cts/s. Using cumulative rates, we measure a T90 of 20.46 +/- 0.007 s. In preliminary analysis, we find that 2853 Compton events are associated with this event.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200423A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27632
SUBJECT: GRB 200423A: Fermi GBM Final Real-time Localization
DATE:    20/04/23 14:04:33 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 13:54:11 UT on 23 Apr 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200423A (trigger 609342856.372534 / 200423579).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 325.0, Dec = 66.8 (J2000 degrees, equivalent to J2000 21h 40m, 66d 47'), with a statistical uncertainty of 11.2 degrees.

The angle from the Fermi LAT boresight is 55.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200423579/quicklook/glg_skymap_all_bn200423579.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200423579/quicklook/glg_healpix_all_bn200423579.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200423579/quicklook/glg_lc_medres34_bn200423579.gif


GRB_name: GRB200423A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27633
SUBJECT: Fermi GRB 200423A: Global MASTER-Net observations report 
DATE:    20/04/23 19:15:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200423A ( Fermi GBM team, GCN 27632) errorbox  14126 sec after notice time and 14153 sec after trigger time at 2020-04-23 17:50:04 UT, with upper limit up to  18.4 mag. Observations started at twilight.  The observations began at zenith distance = 77 deg. The sun  altitude  is -12.8 deg. 

MASTER-Kislovodsk robotic telescope  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 200423A errorbox  14486 sec after notice time and 14513 sec after trigger time at 2020-04-23 17:56:04 UT, with upper limit up to  18.8 mag. The observations began at zenith distance = 73 deg. The sun  altitude  is -18.9 deg. 

The galactic latitude b = 11 deg., longitude l = 106 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1343227

We obtain a following upper limits.  

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

   14183 | 2020-04-23 17:50:04 |      MASTER-Tavrida | (21h 00m 33.51s , +57d 54m 08.0s) |   C |    60 | 16.5 |        
   14279 | 2020-04-23 17:51:40 |      MASTER-Tavrida | (20h 39m 31.20s , +59d 48m 34.3s) |   C |    60 | 17.7 |        
   14375 | 2020-04-23 17:53:16 |      MASTER-Tavrida | (21h 12m 15.78s , +59d 53m 28.8s) |   C |    60 | 17.1 |        
   14471 | 2020-04-23 17:54:51 |      MASTER-Tavrida | (20h 51m 13.97s , +55d 48m 23.9s) |   C |    60 | 16.8 |        
   14543 | 2020-04-23 17:56:04 |   MASTER-Kislovodsk | (21h 08m 47.02s , +61d 29m 40.4s) |   C |    60 | 18.7 |        
   14543 | 2020-04-23 17:56:04 |   MASTER-Kislovodsk | (20h 51m 50.82s , +61d 57m 51.7s) |   C |    60 | 18.4 |        
   14566 | 2020-04-23 17:56:27 |      MASTER-Tavrida | (21h 00m 43.09s , +57d 55m 11.7s) |   C |    60 | 16.0 |        
   14624 | 2020-04-23 17:57:25 |   MASTER-Kislovodsk | (20h 44m 47.52s , +57d 31m 09.8s) |   C |    60 | 18.6 |        
   14624 | 2020-04-23 17:57:25 |   MASTER-Kislovodsk | (20h 29m 47.74s , +57d 59m 33.6s) |   C |    60 | 18.4 |        
   14660 | 2020-04-23 17:58:00 |      MASTER-Tavrida | (21h 15m 03.18s , +57d 45m 51.8s) |   C |    60 | 16.4 |        
   14704 | 2020-04-23 17:58:45 |   MASTER-Kislovodsk | (20h 34m 54.08s , +61d 30m 08.9s) |   C |    60 | 18.7 |        
   14704 | 2020-04-23 17:58:45 |   MASTER-Kislovodsk | (20h 17m 57.28s , +61d 58m 36.6s) |   C |    60 | 18.4 |        
   14754 | 2020-04-23 17:59:35 |      MASTER-Tavrida | (20h 40m 24.67s , +59d 52m 12.7s) |   C |    60 | 17.4 |        
   14847 | 2020-04-23 18:01:08 |      MASTER-Tavrida | (20h 55m 27.31s , +59d 48m 12.3s) |   C |    60 | 18.1 |        
   14865 | 2020-04-23 18:01:26 |   MASTER-Kislovodsk | (21h 08m 53.60s , +61d 29m 01.2s) |   C |    60 | 18.8 |        
   14865 | 2020-04-23 18:01:26 |   MASTER-Kislovodsk | (20h 51m 57.73s , +61d 57m 15.2s) |   C |    60 | 18.5 |        
   14943 | 2020-04-23 18:02:44 |      MASTER-Tavrida | (21h 12m 15.51s , +59d 51m 56.1s) |   C |    60 | 17.4 |        
   14946 | 2020-04-23 18:02:46 |   MASTER-Kislovodsk | (20h 44m 51.25s , +57d 30m 44.6s) |   C |    60 | 18.6 |        
   14946 | 2020-04-23 18:02:46 |   MASTER-Kislovodsk | (20h 29m 51.48s , +57d 59m 09.5s) |   C |    60 | 18.4 |        
   15026 | 2020-04-23 18:04:07 |   MASTER-Kislovodsk | (20h 34m 51.73s , +61d 29m 34.6s) |   C |    60 | 18.7 |        
   15026 | 2020-04-23 18:04:07 |   MASTER-Kislovodsk | (20h 17m 55.17s , +61d 58m 03.1s) |   C |    60 | 18.5 |        
   15038 | 2020-04-23 18:04:18 |      MASTER-Tavrida | (21h 27m 26.20s , +59d 47m 24.2s) |   C |    60 | 17.3 |        
   15131 | 2020-04-23 18:05:52 |      MASTER-Tavrida | (20h 51m 44.20s , +55d 56m 42.9s) |   C |    60 | 16.2 |        
   15225 | 2020-04-23 18:07:26 |      MASTER-Tavrida | (21h 05m 30.10s , +55d 48m 02.3s) |   C |    60 | 17.0 |        
   15268 | 2020-04-23 18:08:09 |   MASTER-Kislovodsk | (21h 33m 57.09s , +55d 30m 40.5s) |   C |    60 | 18.0 |        
   15268 | 2020-04-23 18:08:09 |   MASTER-Kislovodsk | (21h 19m 46.46s , +55d 58m 53.5s) |   C |    60 | 17.8 |        
   15320 | 2020-04-23 18:09:01 |      MASTER-Tavrida | (21h 15m 47.49s , +57d 54m 58.1s) |   C |    60 | 15.9 |        
   15348 | 2020-04-23 18:09:29 |   MASTER-Kislovodsk | (20h 49m 33.47s , +63d 29m 56.2s) |   C |    60 | 18.7 |        
   15349 | 2020-04-23 18:09:29 |   MASTER-Kislovodsk | (20h 31m 24.69s , +63d 58m 23.1s) |   C |    60 | 18.7 |        
   15416 | 2020-04-23 18:10:37 |      MASTER-Tavrida | (20h 55m 24.65s , +59d 46m 16.7s) |   C |    60 | 18.2 |        
   15432 | 2020-04-23 18:10:53 |   MASTER-Kislovodsk | (21h 45m 03.93s , +57d 28m 33.3s) |   C |    60 | 17.1 |        
   15432 | 2020-04-23 18:10:53 |   MASTER-Kislovodsk | (21h 30m 06.44s , +57d 56m 37.2s) |   C |    60 | 16.9 |        
   15511 | 2020-04-23 18:12:12 |      MASTER-Tavrida | (21h 28m 16.02s , +59d 51m 39.5s) |   C |    60 | 17.5 |        
   15593 | 2020-04-23 18:13:34 |   MASTER-Kislovodsk | (21h 34m 00.76s , +55d 30m 36.1s) |   C |    60 | 18.0 |        
   15593 | 2020-04-23 18:13:34 |   MASTER-Kislovodsk | (21h 19m 50.10s , +55d 58m 50.7s) |   C |    60 | 17.9 |        
   15608 | 2020-04-23 18:13:49 |      MASTER-Tavrida | (21h 05m 33.37s , +55d 47m 46.8s) |   C |    60 | 17.1 |        
   15674 | 2020-04-23 18:14:54 |   MASTER-Kislovodsk | (20h 49m 31.49s , +63d 29m 15.1s) |   C |    60 | 18.8 |        
   15674 | 2020-04-23 18:14:54 |   MASTER-Kislovodsk | (20h 31m 23.11s , +63d 57m 42.5s) |   C |    60 | 18.6 |        
   15703 | 2020-04-23 18:15:24 |      MASTER-Tavrida | (21h 09m 09.89s , +63d 47m 22.9s) |   C |    60 | 18.2 |        
   15769 | 2020-04-23 18:16:29 |   MASTER-Kislovodsk | (21h 45m 12.04s , +57d 30m 08.3s) |   C |    60 | 18.1 |        
   15769 | 2020-04-23 18:16:29 |   MASTER-Kislovodsk | (21h 30m 13.62s , +57d 58m 13.2s) |   C |    60 | 18.0 |        
   15797 | 2020-04-23 18:16:57 |      MASTER-Tavrida | (21h 25m 51.75s , +61d 47m 37.1s) |   C |    60 | 17.8 |        
   15888 | 2020-04-23 18:18:29 |      MASTER-Tavrida | (20h 08m 25.02s , +59d 52m 16.1s) |   C |    60 | 18.3 |        
   16076 | 2020-04-23 18:21:37 |      MASTER-Tavrida | (21h 09m 06.49s , +63d 46m 26.7s) |   C |    60 | 18.3 |        
   16169 | 2020-04-23 18:23:10 |      MASTER-Tavrida | (21h 25m 57.06s , +63d 47m 26.0s) |   C |    60 | 18.2 |        
   16243 | 2020-04-23 18:24:24 |   MASTER-Kislovodsk | (21h 08m 02.49s , +65d 29m 21.2s) |   C |    60 | 18.3 |        
   16243 | 2020-04-23 18:24:24 |   MASTER-Kislovodsk | (20h 48m 22.91s , +65d 57m 24.7s) |   C |    60 | 17.9 |        
   16264 | 2020-04-23 18:24:45 |      MASTER-Tavrida | (21h 26m 58.40s , +61d 49m 39.4s) |   C |    60 | 17.7 |        
   16358 | 2020-04-23 18:26:19 |      MASTER-Tavrida | (21h 42m 50.38s , +61d 47m 18.6s) |   C |    60 | 17.7 |        
   16452 | 2020-04-23 18:27:53 |      MASTER-Tavrida | (20h 08m 31.66s , +59d 53m 07.6s) |   C |    60 | 18.4 |        
   16533 | 2020-04-23 18:29:14 |      MASTER-Tavrida | (20h 24m 24.58s , +59d 51m 52.2s) |   C |    60 | 18.4 |        
   16721 | 2020-04-23 18:32:21 |      MASTER-Tavrida | (21h 25m 57.65s , +53d 58m 06.1s) |   C |    60 | 13.3 |        
   16815 | 2020-04-23 18:33:55 |      MASTER-Tavrida | (21h 25m 54.35s , +63d 46m 03.5s) |   C |    60 | 18.1 |        
   16910 | 2020-04-23 18:35:31 |      MASTER-Tavrida | (21h 44m 03.20s , +61d 50m 05.5s) |   C |    60 | 17.5 |        
   16991 | 2020-04-23 18:36:52 |      MASTER-Tavrida | (20h 24m 23.55s , +59d 52m 49.3s) |   C |    60 | 18.4 |        
   17085 | 2020-04-23 18:38:26 |      MASTER-Tavrida | (21h 25m 32.42s , +53d 47m 42.3s) |   C |    60 | 16.1 |        
   17350 | 2020-04-23 18:42:51 |      MASTER-Tavrida | (21h 43m 20.72s , +59d 46m 57.6s) |   C |    60 | 17.7 |        
   17445 | 2020-04-23 18:44:26 |      MASTER-Tavrida | (21h 45m 28.36s , +63d 47m 01.1s) |   C |    60 | 17.9 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200424A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27634
SUBJECT: GRB 200424A: a long GRB detected by INTEGRAL
DATE:    20/04/24 12:56:06 GMT
FROM:    Sandro Mereghetti at IASF-Milano/INAF  <sandro.mereghetti@inaf.it>

S.Mereghetti (INAF, IASF-Milano), D.Gotz (CEA, Saclay),  C.Ferrigno,
E.Bozzo, V.Savchenko (ISDC, Versoix), L.Ducci (IAAT, Germany and ISDC,
Versoix), and J.Borkowski (CAMK, Torun) report:

A long gamma ray burst lasting at least 70 s has been detected by IBAS in
the
IBIS/ISGRI data at 12:07:10  UT of April 24, 2020

The refined coordinates (J2000) are:

R.A. = 307.5057   deg
DEC. = -39.6939 deg

with an uncertainty of  1.5   arcmin (90% c.l.).

The burst light curve is affected by telemetry saturation due to the burst
brightness.
Therefore we can provide only a lower limit on its  20-200 keV fluence of
3e-6 erg/cm2 over a 70 s integration time.

A plot of the light curve will  be posted at
http://ibas.iasf-milano.inaf.it/IBAS_Results.html


GRB_name: GRB200422A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27635
SUBJECT: Konus-Wind observation of GRB 200422A
DATE:    20/04/24 13:49:14 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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

The long-duration, very bright GRB 200422A
(IPN triangulation: Hurley et al., GCN Circ. 27626;
AstroSat-CZTI detection: Gupta et al., GCN Circ. 27630)
triggered Konus-Wind at T0=26537.847 s UT (07:22:17.847).

The burst light curve shows a multipeaked structure
which starts at ~T0-8.3 s and has a total duration of ~40 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200422_T26537/

As observed by Konus-Wind, the burst
had a fluence of 5.12(-0.15,+0.15)x10^-4 erg/cm2,
and a 64-ms peak flux, measured from T0+3.728 s,
of 1.42(-0.12,+0.12)x10^-4 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+38.656 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.67(-0.05,+0.05),
the high energy photon index beta = -1.94(-0.04,+0.04),
the peak energy Ep = 552(-38,+42) keV
(chi2 = 105/97 dof).

The spectrum near the maximum count rate
(measured from T0+3.584 to T0+4.096 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.63(-0.11,+0.12),
the high energy photon index beta = -1.89(-0.09,+0.07),
the peak energy Ep = 762(-138,+174) keV
(chi2 = 89/79 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB200424A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27636
SUBJECT: GRB 200424A: Swift ToO observations
DATE:    20/04/24 15:48:43 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a ToO observation of the INTEGRAL GRB 200424A. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00020989

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 INTEGRAL 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: GRB200424A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27637
SUBJECT: GRB 200424A: LCO Optical Upper Limit
DATE:    20/04/24 20:24:56 GMT
FROM:    Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>

R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:

We observed INTEGRAL GRB 200424A (Mereghetti et al., GCN 27634) with the LCO 1-m Sinistro instrument at the Siding Spring Observatory, Australia site, on April 24, from 18:48 to 19:23 UT (corresponding to 6.68 to 7.27 hours from the GRB trigger time) with the Bessel I and R filters.

We performed a series of 5x240s exposures in R and 4x240s in I. We do not detect any fading sources in the individual frames (or in stacked images).  Using the USNO-B.1 catalog as reference, we obtain the following 3-sigma upper limits:

R > 24.83

I > 22.93

These magnitudes are not corrected for galactic extinction.

R.S. is funded by NSF AST grant #1831682


GRB_name: GRB200425A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27638
SUBJECT: GRB 200425A: Swift detection of a burst
DATE:    20/04/25 00:40:11 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

M. G. Bernardini (INAF-OAB), P. D'Avanzo (INAF-OAB), J.D. Gropp (PSU),
J. A. Kennea (PSU), N. J. Klingler (PSU), S. Laha (GSFC/UMBC/CRESST),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), M. J. Moss (GWU), D. M. Palmer (LANL),
T. Sbarrato (INAF-OAB) and M. H. Siegel (PSU) report on behalf of the
Neil Gehrels Swift Observatory Team:

At 00:16:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200425A (trigger=967774).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 85.241, -13.459 which is 
   RA(J2000) = 05h 40m 58s
   Dec(J2000) = -13d 27' 31"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The immediately-available BAT light curve
data only extends to T+8s, at which time the GRB was still active
with a multi-peaked structure.  The peak count rate up to that time
was ~1000 counts/sec (15-350 keV), at ~3 sec after the trigger. 

The XRT began observing the field at 00:17:52.2 UT, 90.5 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 85.2198, -13.4352 which
is equivalent to:
   RA(J2000)  = 05h 40m 52.76s
   Dec(J2000) = -13d 26' 06.8"
with an uncertainty of 2.9 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.  We cannot determine whether the source
is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 1.59
x 10^21 cm^-2 (Willingale et al. 2013). 

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 0.16. 

Burst Advocate for this burst is M. G. Bernardini (grazia.bernardini AT brera.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: GRB200425A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27639
SUBJECT: GRB 200425A: Enhanced Swift-XRT position
DATE:    20/04/25 07:38:38 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 3121 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 200425A, 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 = 85.21950, -13.43511 which is equivalent
to:

RA (J2000): 05h 40m 52.68s
Dec (J2000): -13d 26' 06.4"

with an uncertainty of 1.6 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: GRB200424A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27640
SUBJECT: GRB 200424A: Swift-XRT observations
DATE:    20/04/25 11:11:26 GMT
FROM:    Paolo D'Avanzo at INAF - OAB  <paolo.davanzo@inaf.it>

M. Perri (ASDC), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), D.N. Burrows
(PSU), J. D. Gropp (PSU), J.A. Kennea (PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester) and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the INTEGRAL-detected
burst GRB 200424A (Mereghetti et al. GCN Circ. 27634), collecting 5.0
ks of Photon Counting (PC) mode data between T0+13.2 ks and T0+30.7 ks.


One uncatalogued X-ray source has been detected consistent with being
within the INTEGRAL position, however it is below the RASS limit and
shows no definitive signs of fading. Therefore, at the present time we
cannot confirm this as the afterglow. Details of this source are given
below:

Source 1:
  RA (J2000):  307.5055  =  20:30:01.31
  Dec (J2000): -39.7001  =  -39:42:00.5
  Error: 3.0 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: (8.3 [+1.7, -1.6])e-3 ct s^-1   
  Distance: 22 arcsec from INTEGRAL position.
  Flux: (2.68 [+0.55, -0.52])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)



Seven uncatalogued sources were also 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/00020989.

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


GRB_name: GRB200425A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27641
SUBJECT: GRB 200425A: Swift-XRT refined Analysis
DATE:    20/04/25 11:48:22 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), J. D. Gropp (PSU), J.A. Kennea
(PSU), A. Tohuvavohu (U. Toronto), J.P. Osborne (U. Leicester), K.L.
Page (U. Leicester), A.P. Beardmore (U. Leicester), A. Melandri
(INAF-OAB) and M.G. Bernardini report on behalf of the Swift-XRT team:

We have analysed 7.7 ks of XRT data for GRB 200425A (Bernardini et al.
GCN Circ. 27638), from 78 s to 34.8 ks after the  BAT trigger. The data
comprise 145 s in Windowed Timing (WT) mode (the first 6 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Beardmore
et al. (GCN Circ. 27639).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=2.5 (+1.3, -0.8). At T+105 s  the decay
flattens to an alpha of -1.5 (+0.0, -0.5). The light curve breaks again
at T+125 s to a decay with alpha=2.78 (+0.39, -0.30),  before a final
break at T+268 s s after which the decay index is 1.13 (+/-0.06).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.11 (+0.17, -0.16). The
best-fitting absorption column is  5.8 (+1.0, -0.9) x 10^21 cm^-2, in
excess of the Galactic value of 1.6 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.02 (+0.26, -0.25)
and a best-fitting absorption column of 7.2 (+2.1, -1.8) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.4 x 10^-11 (7.8 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      7.2 (+2.1, -1.8) x 10^21 cm^-2
Galactic foreground: 1.6 x 10^21 cm^-2
Excess significance: 5.2 sigma
Photon index:      2.02 (+0.26, -0.25)

If the light curve continues to decay with a power-law decay index of
1.13, the count rate at T+24 hours will be 2.8 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x
10^-13 (2.2 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/00967774.

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


GRB_name: GRB200424A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27642
SUBJECT: GRB 200424A: AstroSat CZTI detection
DATE:    20/04/25 11:54:17 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200424A, which was also detected by  INTEGRAL (Mereghetti S. et al., GCN #27634), Swift(Evans P. et al., GCN #27636) and  LCO (Strausbaugh R. et al., GCN #27637).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 2020-04-24 12:07:18.525 UT. The measured peak count rate associated with the burst is 232 +/- 28 cts/s above the background in the combined data of four quadrants, with a total of 1849 +/- 44 cts. The local mean background count rate was 596 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 43.3 +/- 0.02 s. 

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200425A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27643
SUBJECT: GRB 200425A: Swift/UVOT Upper Limits
DATE:    20/04/25 13:23:07 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and M. G. Bernardini (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of
GRB 200425A 94 s after the BAT trigger (Bernardini et al.,
GCN Circ. 27638). No optical afterglow consistent with the
XRT position (Bernardini et al. GCN Circ. 27638)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            94          244          147         >20.7
u_FC               253          503          246         >19.9
white               94          728          186         >20.5
v                  585          778           39         >18.6
b                  510          704           39         >19.1
u                  253          679          265         >19.9
w1                 635          827           39         >18.4
m2                 610          802           39         >18.9
w2                 560          753           39         >18.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.16 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200425B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27644
SUBJECT: GRB 200425B: Fermi GBM Final Real-time Localization
DATE:    20/04/25 17:00:15 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 16:49:50 UT on 25 Apr 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200425B (trigger 609526195.945476 / 200425701).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 304.6, Dec = 38.2 (J2000 degrees, equivalent to J2000 20h 18m, 38d 12'), with a statistical uncertainty of 7.2 degrees.

The angle from the Fermi LAT boresight is 65.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200425701/quicklook/glg_skymap_all_bn200425701.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200425701/quicklook/glg_healpix_all_bn200425701.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200425701/quicklook/glg_lc_medres34_bn200425701.gif


GRB_name: GRB200425A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27645
SUBJECT: Swift GRB 200425A: Global MASTER-Net observations report 
DATE:    20/04/25 17:18:35 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200425A ( M. G. Bernardini et al., GCN 27638) errorbox  60241 sec after notice time and 60296 sec after trigger time at 2020-04-25 17:01:17 UT, with upper limit up to  19.7 mag. Observations started at twilight.  The observations began at zenith distance = 45 deg. The sun  altitude  is -12.2 deg. 

The galactic latitude b = -21 deg., longitude l = 218 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1343952

We obtain a following upper limits.  

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

   60386 |         MASTER-SAAO |   C |   180 | 19.2 |        
   60434 |         MASTER-SAAO |   C |   180 | 19.2 |        
   60666 |         MASTER-SAAO |   C |   180 | 19.7 |        
   60713 |         MASTER-SAAO |   C |   180 | 19.7 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200425A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27646
SUBJECT: GRB 200425A: LCO Optical Upper Limits
DATE:    20/04/25 17:42:20 GMT
FROM:    Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>

R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:

We observed Swift GRB 200425A (Bernardini et al., GCN 27638) with the LCO 1-m Sinistro instrument at the Siding Spring Observatory, Australia site, on April 25, from 08:26 to 09:07 UT (corresponding to 8.17 to 8.85 hours from the GRB trigger time) with the Bessel I and R filters.

We performed a series of 5x240s exposures in R and I. We do not detect any fading sources in the individual frames (or in stacked images) in the Enhanced Swift-XRT position region (Beardmore et al., GCN 27639).  Using the USNO-B.1 catalog as reference, we obtain the following 3-sigma upper limits:

R > 22.45

I > 21.96

These magnitudes are not corrected for galactic extinction.

R.S. is funded by NSF AST grant #1831682


GRB_name: GRB200423A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27647
SUBJECT: IPN triangulation of GRB 200423A (short)
DATE:    20/04/25 22:02:12 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>

A. Ridnaia, D. Svinkin, and K. Hurley, on behalf of the IPN,

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

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
report:

The short-duration GRB 200423A
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 27632)
was detected by Fermi (GBM trigger 609342856) and
INTEGRAL (SPI-ACS) at about 50051 s UT (13:54:11).

We have triangulated it to a GBM-INTEGRAL annulus centered at
RA(2000)=234.403 deg (15h 37m 37s)  Dec(2000)=+51.175 deg (+51d 10' 31"),
whose radius is 40.464 +/- 3.464 deg (3 sigma).

The IPN localization is consistent with, but reduces the area of, the
Fermi-GBM one.

This localization may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB200423_T50051/IPN/


GRB_name: GRB200424A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27648
SUBJECT: GRB 200424A: Swift/UVOT Upper Limits
DATE:    20/04/25 23:20:23 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) reports on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the INTEGRAL GRB 200424A
(Mereghetti et al. GCN Circ. 27634) between T0+17 ks and T0+31 ks,
where T0 = 2020-04-24 12:06:45 UT.
We report here the UOT results for source #1 found by the Swift/XRT
(D'Avanzo et al., GCN Circ. 27640).

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(ks)   T_stop(ks)      Exp(s)         Mag

v                   18           30          236         >19.1
b                   17           30          236         >20.2
u                   17           30          236         >19.9
w1                  17           30          492         >19.9
m2                  17           31         2678         >20.8
w2                  17           30          944         >20.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.05 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200425A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27650
SUBJECT: GRB 200425A: Swift-BAT refined analysis
DATE:    20/04/26 00:21:17 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC),
M. G. Bernardini (INAF-OAB),  J. R. Cummings (CPI),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (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 200425A (trigger #967774)
(Bernardini et al., GCN Circ. 27638).  The BAT ground-calculated position is
RA, Dec = 85.217, -13.399 deg which is
   RA(J2000)  =  05h 40m 52.2s
   Dec(J2000) = -13d 23' 58.1"
with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a weak pulse that starts at ~T-10 s,
peaks at ~T+3 s, and ends at ~T+10 s. In addition, there is some weak
emission that starts at ~T-50 s and lasts till ~T+60 s. T90 (15-350 keV)
is 81.0 +- 21.7 sec (estimated error including systematics).

The time-averaged spectrum from T-47.59 to T+58.41 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
1.30 +- 0.21.  The fluence in the 15-150 keV band is 1.2 +- 0.2 x 10^-6
erg/cm2.
The 1-sec peak photon flux measured from T+2.41 sec in the 15-150 keV band
is 0.7 +- 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/967774/BA/


GRB_name: GRB200412B
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27653
SUBJECT: Gagarin-day GRB 200412B: observations with the 3.6m Devasthal Optical Telescope
DATE:    20/04/26 11:12:48 GMT
FROM:    Shashi Bhushan Pandey at ARIES, INDIA  <shashi@aries.res.in>

Amit Kumar, S. B. Pandey, Amar Aryan, Brijesh Kumar and Kuntal Misra (ARIES Nainital), 
on behalf of a larger GRB collaboration. 


Fermi-GBM triggered GRB 200412B (GCNCs 27547, 27548i, 27558) prompt emissions 
and high energy observations were also carried out by Fermi-LAT (GCNC 27557) and 
other space-based facilities like Konus-Wind (GCNC 27581), ASTROSAT (GCNC 27563), 
CALET (GCNC 27572) and HXMT (GCNC 27567). Categorised as a long-duration GRB, 
Swift-XRT triggered and found a X-ray afterglow counterpart (GCNC 27561, 27600) decaying 
typical to those seen in case of other long duration bursts at the epoch of observations. 

Our joint spectral analysis of the combined Fermi GBM-LAT data yields E_peak ~ 250 +/- 18 
keV and spectral slope \beta ~ -2.8 +/- 0.4 above 100 MeV, similar to those reported in 
GCNC 27558 and GCNC 27581. Once used with the empirical Amati relation, the estimated 
value of the E_peak and the observed fluence values (GCNC 27558, GCNC 27581) place a 
constrain of the redshift to be 0.3 < z < 1.5 for GRB 200412B. 

The optical counterpart of the Gagarin-day burst was discovered by MASTER group of 
telescopes (GCNC 27555, 27556) and follow-up observations were continued by several 
ground-based facilities (GCNCs 27564, 27566, 27567, 27567, 27570, 27571, 27574, 27575, 
27576, 27583, 27593, 27598, 27604, 27605 and 27610). 

Late time follow-up observations of the optical counterpart were initiated using the 4Kx4K CCD 
Imager (Pandey et al. 2017, arXiv:1711.05422v1) mounted at the axial port of the 3.6m 
Devasthal Optical Telescope of ARIES Nainital starting on 15th April and continued till 25th April 
2020. Multiple frames having exposure times of 360s each were taken in various broad-band filters 
including Ic, Rc and g-bands. A fading afterglow candidate was clearly seen in single as well as in 
stacked frames decayed around ~ 3 mag during our observing run. We report following preliminary 
brightness of the optical afterglow seen in our stacked frames calibrated against UNSOB1 and 
PanSTARRS nearby stars. 

Start time, 23 April 20.61 UT, 360*12, Rc, 24.62+/-0.12, seeing ~ 0.8 arcsec 

Start time, 24 April 19.71 UT, 360*10, g, 25.21+/-0.10, seeing ~ 0.9 arcsec 

Once clubbed along with published GCNC values in R-band, our late time observations indicate towards 
a power-law decay nature of the afterglow as seen in case of other well-monitored afterglows. The temporal 
decay index between one day to the epoch of our observations demand a power-law temporal flux-decay 
index of ~ 1.78+-0.15. This temporal decay is similar to those seen at XRT frequencies and might indicate 
towards possible early time jet-break, if any. It is also to be cautioned that possible underlying host galaxy 
contamination to our late time Rc-band stacked frames can not be ruled out. Detailed analysis of the data is 
ongoing. 

To decipher about late time nature of the temporal decay of the afterglow and to detect the host galaxy or 
possible underlying supernova, observations using bigger optical-NIR facilities are encouraged. 

This circular may be cited. 

3.6m Devasthal Optical Telescope (DOT) is a recently commissioned facility in Northern Himalayan region of India 
(long:79 41 04E, lat:29 21 40N, alt:2540m) owned and operated by the Aryabhatta Research Institute of 
Observational Sciences (ARIES), Nainital (https://www.aries.res.in). Authors of this GCN circular thankfully 
acknowledge consistent support from the staff members to run and maintain the 3.6m DOT and specially to 
Director ARIES to make these observations possible during the ongoing COVID19 triggered lock-down phase. 


GRB_name: GRB200501A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27673
SUBJECT: GRB 200501A: Fermi GBM Final Real-time Localization
DATE:    20/05/01 10:36:01 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 10:25:44 UT on 1 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200501A (trigger 610021549.84722 / 200501435).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 45.9, Dec = -19.5 (J2000 degrees, equivalent to J2000 03h 03m, -19d 30'), with a statistical uncertainty of 8.3 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/2020/bn200501435/quicklook/glg_skymap_all_bn200501435.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200501435/quicklook/glg_healpix_all_bn200501435.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200501435/quicklook/glg_lc_medres34_bn200501435.gif


GRB_name: GRB200424A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27676
SUBJECT: GRB 200424A: Swift-XRT afterglow detection
DATE:    20/05/02 08:48:04 GMT
FROM:    Paolo D'Avanzo at INAF - OAB  <paolo.davanzo@inaf.it>

M. Perri (ASDC), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), D.N. Burrows
(PSU), J. D. Gropp (PSU), J.A. Kennea (PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester) and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team:

Swift-XRT has conducted further observations of the field of the
INTEGRAL-detected burst GRB 200424A (Mereghetti et al. GCN Circ.
27634). The observations now extend from T0+17.1 ks to T0+633.1 ks. 

Of the sources reported by Perri et al. (GCN Circ. 27640), "Source 1"
is fading with 3-sigma significance, and is therefore likely the GRB
afterglow. Using 1970 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 = 307.50547, -39.70013
which is equivalent to:

RA (J2000): 20h 30m 01.31s
Dec(J2000): -39d 42' 00.5"

with an uncertainty of 3.0 arcsec (radius, 90% confidence). This
position is 22 arcsec from the INTEGRAL position.  The source is fading
with alpha >0.3.

The results of the XRT-team automatic analysis of the likely afterglow
are at https://www.swift.ac.uk/ToO_GRBs/00020989/Source1.php.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00020989.

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


GRB_name: GRB200502A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27677
SUBJECT: GRB 200502A: Fermi GBM Final Real-time Localization
DATE:    20/05/02 13:56:49 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 13:46:33 UT on 2 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200502A (trigger 610119998.856084 / 200502574).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 289.5, Dec = 38.6 (J2000 degrees, equivalent to J2000 19h 18m, 38d 36'), with a statistical uncertainty of 2.7 degrees.

The angle from the Fermi LAT boresight is 138.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200502574/quicklook/glg_skymap_all_bn200502574.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200502574/quicklook/glg_healpix_all_bn200502574.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200502574/quicklook/glg_lc_medres34_bn200502574.gif


GRB_name: GRB200503A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27680
SUBJECT: AstroSat CZTI detection : GRB200503A
DATE:    20/05/03 13:05:09 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma, A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data showed the detection of a long GRB 200503A.
The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 2020-05-03 05:02:01.500 UT. The measured peak count rate associated with the burst is 2021 +/- 50.3 cts/s above the background in the combined data of four quadrants, with a total of 28736 +/- 52.5 cts. The local mean background count rate was 601 +/- 1.0 cts/s. Using cumulative rates, we measure a T90 of 38.6 +/- 0.01 s. In preliminary analysis, we find that 2294 Compton events are associated with this event.
It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.
CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200503B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27682
SUBJECT: GRB 200503B: Fermi GBM Final Real-time Localization
DATE:    20/05/03 17:28:56 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 17:18:33 UT on 3 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200503B (trigger 610219118.569706 / 200503721).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 250.6, Dec = -20.0 (J2000 degrees, equivalent to J2000 16h 42m, -20d 00'), with a statistical uncertainty of 4.1 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/2020/bn200503721/quicklook/glg_skymap_all_bn200503721.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200503721/quicklook/glg_healpix_all_bn200503721.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200503721/quicklook/glg_lc_medres34_bn200503721.gif


GRB_name: GRB200503B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27683
SUBJECT: GRB 200503B: BALROG localization (Fermi Trigger 610219118 / GRB 200503721)
DATE:    20/05/03 17:49:11 GMT
FROM:    Jochen Greiner at MPE,Garching  <jcg@mpe.mpg.de>

B. Biltzinger, F. Kunzweiler, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
610219118 at 17:18:33 on 03 May 2020 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) = 248.5+/-2.7 deg
Decl.(2000.0) = -19.2+/-2.7 deg
We estimate an additional systematic error of 1 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB200503721/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB200503721/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB200503721/json

                        


GRB_name: GRB200502A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27684
SUBJECT: GRB 200502A: AGILE observations
DATE:    20/05/03 19:41:14 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi@gmail.com>

A. Ursi (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), C. Casentini (INAF/IAPS), M. Pilia
(INAF/OA-Cagliari), C. Pittori (SSDC, and INAF/OAR),  A. Argan, M.
Cardillo, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and
INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste
and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the
AGILE Team:

The AGILE satellite detected the long burst GRB 200502A, reported by
Fermi/GBM (GCN #27677; trigger 610119998.856084/200502574) at T0 =
2020-05-02 13:46:33 (UT).

The event is visible in the scientific ratemeters of the SuperAGILE (SA;
20-60 keV) detector. The event lasted ~30 s and released a total number of
~1000 counts in the SA ratemeters (above a background of ~45 Hz). The SA
ratemeters light curve can be found at
http://www.agilescienceapp.it/notices/RM_SA_GRB200502A.png .

Additional analysis of AGILE data is in progress.


GRB_name: GRB200503A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27685
SUBJECT: GRB 200503A: AGILE observations
DATE:    20/05/03 19:41:20 GMT
FROM:    Alessandro Ursi at INAF/IAPS  <alessandro.ursi@gmail.com>

A. Ursi (INAF/IAPS), F. Verrecchia (SSDC, and INAF/OAR), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), C. Casentini (INAF/IAPS), M. Pilia
(INAF/OA-Cagliari), C. Pittori (SSDC, and INAF/OAR),  A. Argan, M.
Cardillo, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and
INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste
and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the
AGILE Team:

The AGILE satellite detected the long burst GRB 200503A at T0 = 2020-05-03
05:01:44 (UT), reported by AstroSat CZTI (GCN #27680, Gupta et al.).

The event is visible in the scientific ratemeters of the SuperAGILE (SA;
20-60 keV), Anti-Coincidence (AC, 50-200 keV), and MiniCALorimeter (MCAL;
0.4-100 MeV) detectors. The burst light curve shows a multi-peaked time
profile that lasted ~25 s. The event released 3700 counts in the AC
ratemeters (above a background of ~3500 Hz), 1800 counts in the MCAL
ratemeters (above a background of ~2600 Hz), and 560 counts in the SA
ratemeters (above a background of 40 Hz). The ratemeters light curves can
be found at http://www.agilescienceapp.it/notices/RM_GRB200503A.png .

Additional analysis of AGILE data is in progress.


GRB_name: GRB200502A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27686
SUBJECT: GRB 200502A: AstroSat CZTI detection
DATE:    20/05/04 08:39:09 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200502A, which was also detected by Fermi GBM (GCN #27677) and  AGILE (Ursi A. et al., GCN #27684).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 2020-05-02 13:46:33.887 UT. The measured peak count rate associated with the burst is 151 +/- 19 cts/s above the background in the combined data of four quadrants, with a total of 650 +/- 18 cts. The local mean background count rate was 540 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 7.67 +/- 0.10 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200505A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27689
SUBJECT: GRB 200505A: Fermi GBM Final Real-time Localization
DATE:    20/05/06 00:00:57 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 23:50:44 UT on 5 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200505A (trigger 610415449.084498 / 200505994).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 81.1, Dec = -49.0 (J2000 degrees, equivalent to J2000 05h 24m, -49d 00'), with a statistical uncertainty of 3.5 degrees.

The angle from the Fermi LAT boresight is 17.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200505994/quicklook/glg_skymap_all_bn200505994.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200505994/quicklook/glg_healpix_all_bn200505994.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200505994/quicklook/glg_lc_medres34_bn200505994.gif


GRB_name: GRB200506A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27690
SUBJECT: GRB 200506A: Fermi GBM Final Real-time Localization
DATE:    20/05/06 00:39:00 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 00:28:41 UT on 6 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200506A (trigger 610417726.052718 / 200506020).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 271.7, Dec = -4.4 (J2000 degrees, equivalent to J2000 18h 06m, -4d 24'), with a statistical uncertainty of 3.9 degrees.

The angle from the Fermi LAT boresight is 87.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506020/quicklook/glg_skymap_all_bn200506020.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506020/quicklook/glg_healpix_all_bn200506020.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506020/quicklook/glg_lc_medres34_bn200506020.gif


GRB_name: GRB200506B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27691
SUBJECT: GRB 200506B: Fermi GBM Final Real-time Localization
DATE:    20/05/06 05:09:51 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 04:59:44 UT on 6 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200506B (trigger 610433989.715966 / 200506208).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 82.2, Dec = -6.7 (J2000 degrees, equivalent to J2000 05h 28m, -6d 42'), with a statistical uncertainty of 15.1 degrees.

The angle from the Fermi LAT boresight is 102.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506208/quicklook/glg_skymap_all_bn200506208.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506208/quicklook/glg_healpix_all_bn200506208.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506208/quicklook/glg_lc_medres34_bn200506208.gif


GRB_name: GRB200506C
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27692
SUBJECT: GRB 200506C: Fermi GBM Final Real-time Localization
DATE:    20/05/06 09:51:27 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 09:41:08 UT on 6 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200506C (trigger 610450873.980628 / 200506404).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 190.9, Dec = 40.2 (J2000 degrees, equivalent to J2000 12h 43m, 40d 12'), with a statistical uncertainty of 3.5 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/2020/bn200506404/quicklook/glg_skymap_all_bn200506404.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506404/quicklook/glg_healpix_all_bn200506404.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200506404/quicklook/glg_lc_medres34_bn200506404.gif


GRB_name: GRB200505A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27693
SUBJECT: GRB 200505A: AGILE detection
DATE:    20/05/06 16:14:03 GMT
FROM:    Francesco Verrecchia at SSDC,INAF-OAR  <francesco.verrecchia@ssdc.asi.it>

F. Verrecchia (SSDC, and INAF/OAR), A. Ursi (INAF/IAPS), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), C. Casentini (INAF/IAPS), M.
Pilia (INAF/OA-Cagliari), C. Pittori (SSDC, and INAF/OAR), A. Argan, M.
Cardillo, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and
INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani
(INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University),
A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste
and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the
AGILE Team:

The AGILE satellite detected the long burst GRB 200505A, also reported
by Fermi/GBM (GCN #27689; trigger 610415449.084498/200505994) at
T0 = 2020-05-05 23:50:44 (UT).

The event is visible in the scientific ratemeters of the SuperAGILE (SA;
20-60 keV) detector. The event lasted ~15 s and released a total number of
~630 counts in the SA ratemeters (above a background of ~75 Hz). The SA
ratemeters light curve can be found at
https://tools.ssdc.asi.it/ImgView/Agile/SARatDet1-4-SUM_SciRat_zoom200505A26
.

Additional analysis of AGILE data is in progress.


GRB_name: GRB200422A
Detection_method: INTEGRAL
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27694
SUBJECT: GRB 200422A: INTEGRAL observations
DATE:    20/05/06 17:09:03 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

P. Minaev (IKI), I. Chelovekov (IKI), A. Pozanenko (IKI), S. Grebenev 
(IKI) report on behalf of GRB IKI FuN:

We analyzed publically available data of SPI-ACS detector onboard the 
INTEGRAL observatory. GRB 200422A (Hurley et al., GCN 27626; Gupta et 
al., GCN 27630; Svinkin et al., GCN 27635) did not trigger IBAS 
(http://ibas.iasf-milano.inaf.it/).

The GRB 200422A is detected in SPI-ACS data as very intense burst at 
(UTC) 2020-04-22T07:22:03.1. The T_90 duration of the burst is 12.3 +/- 
0.1 s in SPI-ACS. The fluence in 10-1000 keV energy band is 3.62e-4 
erg/cm2 with statistical error of 5e-6 erg/cm2 (1.0e-4 â€” 1.2e-3 ergs/cm2 
in the 95% confident region, including systematics)  as defined after 
calibration based on long duration GRBs (Chelovekov et al., in 
preparation). We do not detect significant precursor in any 0.1 â€“ 5 sec 
time scale within 500 s prior to the trigger. Probable extended emission 
is detected up to 250 s after the trigger.

The light curve can be found at 
http://grb.rssi.ru/GRB200422A/GRB200422A_SPI-ACS_LC.png

We also put the spectral data of GRB 200422A reported  by Konus-Wind 
(Svinkin et al., GCN 27635) onto E_iso -- E_p diagram (AKA Amati 
relation, see also Minaev et al., MNRAS, 492, 1919 (2020).

A GRB 200422A trajectory of parameters E_iso,i -- E_p,i  along redshift 
restricts the redshift of GRB 200422A  as 2 > z > 0.1, see figure at

http://grb.rssi.ru/GRB200422A/GRB200422A_Ep-Eiso_diagram.png


GRB_name: GRB200506C
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27697
SUBJECT: GRB 200506C: AstroSat CZTI detection
DATE:    20/05/06 19:41:20 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma, A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200506C, which was also detected by Fermi GBM (GCN #27692).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 2020-05-06 09:41:37.093 UT. The measured peak count rate associated with the burst is 307 +/- 25 cts/s above the background in the combined data of four quadrants, with a total of 9495 +/- 228 cts. The local mean background count rate was 547 +/- 1.0 cts/s. Using cumulative rates, we measure a T90 of 205.8 +/- 0.04 s. In preliminary analysis, we find that 756 Compton events are associated with this event.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200506A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27698
SUBJECT: GRB 200506A: AstroSat CZTI detection
DATE:    20/05/07 14:33:06 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the weak detection of a long GRB 200506A, which was also detected by Fermi GBM (GCN #27690).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with the strongest peak at 2020-05-06 00:28:53.176 UT. The measured peak count rate associated with the burst is 143 +/- 20 cts/s above the background in the combined data of four quadrants, with a total of 1364 +/- 27 cts. The local mean background count rate was 538 +/- 1.0 cts/s. Using cumulative rates, we measure a T90 of 26.09 +/- 0.08 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200507A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27699
SUBJECT: GRB 200507A: Fermi GBM Final Real-time Localization
DATE:    20/05/07 16:03:20 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 15:52:58 UT on 7 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200507A (trigger 610559583.838602 / 200507662).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 57.8, Dec = 65.5 (J2000 degrees, equivalent to J2000 03h 51m, 65d 30'), with a statistical uncertainty of 2.2 degrees.

The angle from the Fermi LAT boresight is 46.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200507662/quicklook/glg_skymap_all_bn200507662.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200507662/quicklook/glg_healpix_all_bn200507662.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200507662/quicklook/glg_lc_medres34_bn200507662.gif


GRB_name: GRB200509A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27701
SUBJECT: GRB 200509A: Swift detection of a burst with a possible optical counterpart
DATE:    20/05/09 07:08:31 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

E. Troja (NASA/GSFC/UMCP), V. D'Elia (SSDC), J.D. Gropp (PSU),
N. J. Klingler (PSU), K. L. Page (U Leicester), B. Sbarufatti (PSU),
M. H. Siegel (PSU) and A. Tohuvavohu (U Toronto) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 06:47:17 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200509A (trigger=970886).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 116.450, -4.641 which is 
   RA(J2000) = 07h 45m 48s
   Dec(J2000) = -04d 38' 28"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 20 sec. There is also possible 
further activity for several hundred seconds  The peak count rate
was ~1400 counts/sec (15-350 keV), at ~4 sec after the trigger. 

The XRT began observing the field at 06:49:16.9 UT, 119.6 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 116.42333, -4.63131 which is equivalent
to:
   RA(J2000)  = 07h 45m 41.60s
   Dec(J2000) = -04d 37' 52.7"
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This
location is 101 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.  We cannot determine whether the source
is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (1.58 x
10^21 cm^-2, Willingale et al. 2013), with an excess column of 5.2
(+4.12/-3.39) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of nominal 150.000 seconds with the White
filter starting 123 seconds after the BAT trigger. There is a candidate
afterglow in the list of sources generated on-board at
 RA(J2000)  = 07:45:41.20 = 116.42166
 DEC(J2000) = -04:37:49.4  =  -4.63040
with a 90%-confidence error radius of about 1.10 arc sec. This position is 6.4
arc sec. from the center of the XRT error circle. The estimated magnitude is
19.15. No correction has been made for the expected extinction corresponding to
E(B-V) of 0.13. The 2.7'x2.7' sub-image does not cover the region of
this potential counterpart. 

Burst Advocate for this burst is E. Troja (eleonora.troja 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: GRB200509A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27702
SUBJECT: GRB 200509A: Zadko observatory - Gingin optical upper limits
DATE:    20/05/09 14:04:56 GMT
FROM:    Bruce Gendre at UVI  <bruce.gendre@gmail.com>

B. Gendre, E. Moore, D. Coward, J.A. Moore (OzGrav-UWA),
A. Klotz (IRAP-CNRS-OMP) report:

We imaged the field of GRB 200509A detected by Swift
(trigger 970886, GCN 27701, Troja et al. 2020) with the Zadko robotic 
telescope (D=100cm) located at the Zadko Observatory - Gingin, Australia.

The observations started about 6 hours after the GRB trigger. The 
elevation of the field was at 41 degrees above horizon at the start of 
the observation and decreasing, and weather conditions were good.

Inside the error box of the XRT afterglow, we did not detect any object 
at 2020-05-09T13:00:00, down to a R magnitude of 18.2. No further 
observations are planned.

Magnitudes were estimated with the nearby USNO-B1 stars
and are not corrected for galactic dust extinction.

This message may be cited.


GRB_name: GRB200509A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27703
SUBJECT: GRB 200509A: Enhanced Swift-XRT position
DATE:    20/05/09 16:15:06 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 799 s of XRT Photon Counting mode data and 2 UVOT
images for GRB 200509A, 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 = 116.42238, -4.63042 which is equivalent
to:

RA (J2000): 07h 45m 41.37s
Dec (J2000): -04d 37' 49.5"

with an uncertainty of 1.7 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: GRB200509A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27704
SUBJECT: GRB 200509A: Swift-XRT refined Analysis
DATE:    20/05/09 18:28:52 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto),
B. Sbarufatti (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U.
Leicester), P.A. Evans (U. Leicester), A. Melandri (INAF-OAB), T.
Sbarrato (INAF-OAB) and E. Troja report on behalf of the Swift-XRT
team:

We have analysed 9.4 ks of XRT data for GRB 200509A (Troja et al. GCN
Circ. 27701), from 104 s to 34.9 ks after the  BAT trigger. The data
comprise 7 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. The enhanced
XRT position for this burst was given by Evans et al. (GCN Circ.
27703). The late-time light curve (from T0+5.0 ks) is consistent with a
constant source of mean count rate 1.8e-01 ct/sec. A power-law fit
gives an index of -0.2 (+/-1.2).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.725 (+/-0.020). The
best-fitting absorption column is  1.89 (+0.08, -0.07) x 10^21 cm^-2,
in excess of the Galactic value of 1.6 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.55 (+0.10, -0.08)
and a best-fitting absorption column consistent with the Galactic
value. The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.5 x 10^-11 (5.1 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      1.58 (+0.17, -0.00) x 10^21 cm^-2
Galactic foreground: 1.6 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.55 (+0.10, -0.08)

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00970886.

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


GRB_name: GRB200509A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27705
SUBJECT: GRB 200509A: LCO Optical Afterglow Detection
DATE:    20/05/09 18:36:17 GMT
FROM:    Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>

R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:

We observed Swift GRB 200509A (Troja et al., GCN 27701) with the LCO 1-m Sinistro instrument at the South African Astronomical Observatory site, on May 9, from 16:46 to 17:08 UT (corresponding to 9.63 to 10.0 hours from the GRB trigger time) with the Bessel R and I filters.

We performed a series of 5x120s exposures in R and I. We detect an optical source in stacked images within the Enhanced Swift-XRT position (Evans et al., GCN 27703) that is not present in either USNO or 2MASS catalogs.  Using the USNO-B.1 catalog as reference, we calculate the following magnitudes:

R = 20.94 +/- 0.09

I = 19.44 +/- 0.18

These magnitudes are not corrected for galactic extinction.

R.S. is funded by NSF AST grant #1831682


GRB_name: GRB200509A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27706
SUBJECT: Swift GRB 200509A: Global MASTER-Net observations report 
DATE:    20/05/09 19:38:22 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200509A ( E. Troja et al., GCN 27701) errorbox  42927 sec after notice time and 42979 sec after trigger time at 2020-05-09 18:43:37 UT, with upper limit up to  19.1 mag. The observations began at zenith distance = 56 deg. The sun  altitude  is -36.1 deg. 

The galactic latitude b = 10 deg., longitude l = 224 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1352906

We obtain a following upper limits.  

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

   43070 |         MASTER-SAAO |   C |   180 | 19.1 |        
   43070 |         MASTER-SAAO |   C |   180 | 19.0 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200509B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27707
SUBJECT: GRB 200509B: Fermi GBM Final Real-time Localization
DATE:    20/05/09 19:48:58 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 SHORT GRB

At 19:38:38 UT on 9 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200509B (trigger 610745923.819 / 200509818).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 75.3, Dec = 71.0 (J2000 degrees, equivalent to J2000 05h 01m, 71d 00'), with a statistical uncertainty of 14.2 degrees.

The angle from the Fermi LAT boresight is 114.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200509818/quicklook/glg_skymap_all_bn200509818.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200509818/quicklook/glg_healpix_all_bn200509818.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200509818/quicklook/glg_lc_medres34_bn200509818.gif


GRB_name: GRB200509C
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27708
SUBJECT: GRB 200509C: Fermi GBM Final Real-time Localization
DATE:    20/05/09 23:09:10 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 22:59:04 UT on 9 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200509C (trigger 610757949.499186 / 200509958).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 311.0, Dec = -3.7 (J2000 degrees, equivalent to J2000 20h 44m, -3d 42'), with a statistical uncertainty of 9.3 degrees.

The angle from the Fermi LAT boresight is 108.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200509958/quicklook/glg_skymap_all_bn200509958.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200509958/quicklook/glg_healpix_all_bn200509958.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200509958/quicklook/glg_lc_medres34_bn200509958.gif


GRB_name: GRB200509A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27709
SUBJECT: GRB 200509A: Swift/UVOT Detection
DATE:    20/05/10 00:34:40 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200509A
123 s after the BAT trigger (Troja et al., GCN Circ. 27701). A source
consistent with the XRT position  (Troja et al. GCN Circ. 27701)  is
detected in the initial UVOT exposures.

The preliminary UVOT position is:
    RA  (J2000) =  07:45:41.28 = 116.42200 (deg.)
    Dec (J2000) = -04:37:49.3  =  -4.63035 (deg.)
with an estimated uncertainty of 0.48 arc sec. (radius, 90% confidence).

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              123          273          147         18.92 +/- 0.08
v                  611         1738          122        >18.6
b                  537         1678          117        >19.8
u                  281          531          246         18.46 +/- 0.10
w1                 660         1628          117        >19.0
m2                 636         1604          117        >19.0
w2                 587         1728          136        >19.6

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.13 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200509A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27710
SUBJECT: GRB 200509A: GROWTH-India r band upper limits
DATE:    20/05/10 06:30:58 GMT
FROM:    Varun Bhalerao at Indian Inst of Tech  <varunb@iitb.ac.in>

H. Kumar, V. Bhalerao(IITB), G. C. Anupama, S. Barway, T. Stanzin (IIA), J. Stanzin (IAO) report on behalf of the GROWTH-India collaboration:

We observed GRB200509A reported by (Troja et al., GCN 27701, Gendre et al., GCN 27702, Evans et al., GCN 27703, Lipunov et al., GCN 27706, Kuin et al., GCN 27709) with 0.7m GROWTH-India telescope. We obtained a 550 sec r band exposure starting at UT 2020-05-09T15:04:19. The field was observed at low altitude (< 25 deg). We did not detect any new source up to 19.7 mag within an uncertainty region of 1.7 arcsec (radius, 90% confidence) around RA(J2000) = 07h 45m 41.37s, Dec(J2000) = -04d 37' 49.5" (Evans et al., GCN 27703).

The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree field of view, set up by the Indian Institute of Astrophysics and the Indian Institute of Technology Bombay with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (Hanle), operated by the Indian Institute of Astrophysics (IIA).


GRB_name: GRB200510A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27711
SUBJECT: GRB 200510A: Fermi GBM Final Real-time Localization
DATE:    20/05/10 10:51:33 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 10:41:16 UT on 10 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200510A (trigger 610800081.958626 / 200510445).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 155.1, Dec = -1.9 (J2000 degrees, equivalent to J2000 10h 20m, -1d 53'), with a statistical uncertainty of 1.5 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/2020/bn200510445/quicklook/glg_skymap_all_bn200510445.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200510445/quicklook/glg_healpix_all_bn200510445.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200510445/quicklook/glg_lc_medres34_bn200510445.gif


GRB_name: GRB200510A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27712
SUBJECT: GRB 200510A: BALROG localization (Fermi Trigger 610800081 / GRB 200510445)
DATE:    20/05/10 11:06:03 GMT
FROM:    Jochen Greiner at MPE,Garching  <jcg@mpe.mpg.de>

F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
610800081 at 10:41:16 on 10 May 2020 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) = 155.2+/-2.1 deg
Decl.(2000.0) = -1.9+/-2.9 deg
We estimate an additional systematic error of 2 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB200510445/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB200510445/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB200510445/json

                        


GRB_name: GRB200509A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27713
SUBJECT: GRB 200509A: Swift-BAT refined analysis
DATE:    20/05/10 17:34:13 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

D. M. Palmer (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), T. Sakamoto (AGU),
M. Stamatikos (OSU), E. Troja (NASA/GSFC/UMCP),
T. N. Ukwatta (LANL) (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 200509A (trigger #970886)
(Troja et al., GCN Circ. 27701).  The BAT ground-calculated position is
RA, Dec = 116.415, -4.634 deg which is
   RA(J2000)  =  07h 45m 39.6s
   Dec(J2000) = -04d 38' 02.5"
with an uncertainty of 1.7 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 39%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~T0 and ends at ~T+850 s. The three prominent peaks occur at ~T0,
~T+600 s, and ~T+820 s, respectively. There might be additional burst
emission beyond the available event data range (i.e., > T+963 s).
T90 (15-350 keV) is 828.2 +- 13.4 sec (estimated error including
systematics).

The time-averaged spectrum from T-0.80 to T+848.99 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
1.67 +- 0.09.  The fluence in the 15-150 keV band is 7.3 +- 0.4 x 10^-6
erg/cm2.
The 1-sec peak photon flux measured from T+822.69 sec in the 15-150 keV band
is 1.5 +- 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/970886/BA/


GRB_name: GRB200510A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27716
SUBJECT: GRB 200510A: AstroSat CZTI detection
DATE:    20/05/11 19:50:59 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200510A, which was also detected by Fermi GBM (GCN #27711) and BALROG (Kunzweiler
F. et al.,GCN #27712).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peak of emission with the strongest peak at 2020-05-10 10:41:16.542 UT. The measured peak count rate associated with the burst is 310 +/- 27 cts/s above the background in the combined data of four quadrants, with a total of 967 +/- 10 cts. The local mean background count rate was 496 +/- 1.0 cts/s. Using cumulative rates, we measure a T90 of 9.29 +/- 0.005 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200512A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27726
SUBJECT: GRB 200512A: Swift detection of a burst
DATE:    20/05/12 20:53:23 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

K. K. Simpson (PSU), V. D'Elia (SSDC), C. Gronwall (PSU),
J.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),
D. M. Palmer (LANL), B. Sbarufatti (PSU), M. H. Siegel (PSU) and
A. Tohuvavohu (U Toronto) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 20:33:15 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200512A (trigger=971846).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 7.396, -2.199 which is 
   RA(J2000) = 00h 29m 35s
   Dec(J2000) = -02d 11' 54"
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 20 sec.  The peak count rate
was ~600 counts/sec (15-350 keV), at ~3 sec after the trigger. 

The XRT began observing the field at 20:34:25.5 UT, 69.7 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 7.41520, -2.21052
which is equivalent to:
   RA(J2000)  = 00h 29m 39.65s
   Dec(J2000) = -02d 12' 37.9"
with an uncertainty of 3.5 arcseconds (radius, 90% containment). This
location is 80 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 consistent with the Galactic value of 2.94
x 10^20 cm^-2 (Willingale et al. 2013). 

The initial flux in the 2.5 s image was 7.60e-10 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 250 seconds with the U filter starting
235 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 19.2 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 18.0 mag. No
correction has been made for the expected extinction corresponding to E(B-V) of
0.03. 

Burst Advocate for this burst is K. K. Simpson (kira.simpson1984 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: GRB200512A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27728
SUBJECT: GRB 200512A: Enhanced Swift-XRT position
DATE:    20/05/13 04:28:29 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 744 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 200512A, 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 = 7.41477, -2.21036 which is equivalent
to:

RA (J2000): 00h 29m 39.54s
Dec (J2000): -02d 12' 37.3"

with an uncertainty of 1.4 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: GRB200512A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27729
SUBJECT: GRB 200512A: Swift-XRT refined Analysis
DATE:    20/05/13 15:39:48 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU),
A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), J.P. Osborne
(U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P.
D'Avanzo (INAF-OAB) and K.K. Simpson report on behalf of the Swift-XRT
team:

We have analysed 7.4 ks of XRT data for GRB 200512A (Simpson et al. GCN
Circ. 27726), from 63 s to 58.1 ks after the  BAT trigger. The data
comprise 153 s in Windowed Timing (WT) mode (the first 5 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Goad et al.
(GCN Circ. 27728).

The light curve can be modelled with an initial power-law decay with an
index of alpha=0.42 (+0.20, -0.37), followed by a break at T+161 s to
an alpha of 1.93 (+/-0.10).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.49 (+/-0.13). The
best-fitting absorption column is  2.6 (+0.7, -0.6) x 10^21 cm^-2, in
excess of the Galactic value of 2.9 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.20 (+0.23, -0.22)
and a best-fitting absorption column of 2.4 (+1.4, -1.2) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 6.1 x 10^-11 (6.7 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      2.4 (+1.4, -1.2) x 10^21 cm^-2
Galactic foreground: 2.9 x 10^20 cm^-2
Excess significance: 3.0 sigma
Photon index:      1.20 (+0.23, -0.22)

If the light curve continues to decay with a power-law decay index of
1.93, the count rate at T+24 hours will be 6.7 x 10^-5 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 4.1 x
10^-15 (4.5 x 10^-15) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00971846.

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


GRB_name: GRB200512A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27730
SUBJECT: GRB 200512A: Swift/UVOT Upper Limits
DATE:    20/05/13 16:56:49 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall@milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and K. K. Simpson (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200512A
78 s after the BAT trigger (Simpson et al., GCN Circ. 27726).
No optical afterglow consistent with the enhanced XRT position
(Goad et al., GCN Circ. 27728) 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            78          228          147         >19.9
u_FC               236          486          246         >19.8
v                  567          760           39         >17.1
b                  493          858           58         >19.0
u                  236          833          285         >19.7
w1                 617          809           39         >17.9

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200512A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27731
SUBJECT: Fermi GBM Sub-Threshold Detection of GRB 200512A
DATE:    20/05/13 20:19:43 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

P. Veres (UAH) reports on behalf of the Fermi-GBM Team:


Swift-BAT detected GRB 200512A at 20:33:15 UT (GCN 27726). There was no
Fermi-GBM onboard trigger around the event.

An automated, blind search for short gamma-ray bursts below the onboard
triggering threshold in Fermi-GBM identified no counterparts.


The GBM targeted search [1], the most sensitive, coherent search for
GRB-like signals, was run from +/-30 s around BAT trigger time. A transient
source was identified whose most significant timescale according to the
search is 8.192 s, with a log likelihood ratio of 23. It has consistent
location, and it is consistent with a "normal" spectrum (Band function with
Epeak = 230 keV, alpha = -1.0, beta = -2.3) for a GRB.


[1] Goldstein et al. 2019 arXiv:1903.12597


GRB_name: GRB200512A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27733
SUBJECT: GRB 200512A: LCO Optical Upper Limits
DATE:    20/05/13 20:46:43 GMT
FROM:    Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>

R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:

We observed Swift GRB 200512A (Simpson et al., GCN 27726) with the LCO 1-m Sinistro instrument at the Siding Spring Observatory, Australia site, on May 13, from 19:03 to 19:25 UT (corresponding to 23.50 to 23.87 hours from the GRB trigger time) with the Bessel I and R filters.

We performed a series of 5x120s exposures in R and I. We do not detect any fading sources in the individual frames (or in stacked images).  Using the USNO-B.1 catalog as reference, we obtain the following 3-sigma upper limits:

R > 20.90

I > 20.29

These magnitudes are not corrected for galactic extinction.

R.S. is funded by NSF AST grant #1831682


GRB_name: GRB200514A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27735
SUBJECT: GRB 200514A: MAXI/GSC detection
DATE:    20/05/14 04:28:48 GMT
FROM:    Hitoshi Negoro at Nihon U  <negoro.hitoshi@nihon-u.ac.jp>

Y. Okamoto (Chuo U.), M. Nakajima, K. Kobayashi, H. Negoro,  
M. Aoki,  R. Takagi, K, Asakura, K, Seino, S. Mokumoto (Nihon U.), 
T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN), 
T. Sakamoto, M. Serino, S. Sugita, H. Nishida, A. Yoshida (AGU), 
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, S. Kitakoga (Chuo U.), 
M. Shidatsu (Ehime U.), N. Kawai, R. Adachi, M. Niwano (Tokyo Tech), 
S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka (JAXA), 
Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.), 
H. Tsunemi (Osaka U.), M. Yamauchi, K. Kurogi, K. Miike (Miyazaki U.), 
T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC) 
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered on a bright uncatalogued X-ray transient source
at 02:21:15 UT on 2020 May 14.
Assuming that the source flux was constant over the transit,
we obtain the source position at
(R.A., Dec) = (170.101 deg, 19.633 deg) = (11 20 24, +19 37 58) (J2000) 
with a statistical 90% C.L. elliptical error region 
with long and short radii of 0.26 deg and 0.21 deg, respectively. 
The roll angle of the long axis from the north direction is 46.0 deg counterclockwise. 
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 209 +- 38 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) = (169.291, 18.660) deg = (11 17 09, +18 39 36) (J2000)
(R.A., Dec) = (169.683, 18.463) deg = (11 18 43, +18 27 46) (J2000)
(R.A., Dec) = (170.979, 20.746) deg = (11 23 54, +20 44 45) (J2000)
(R.A., Dec) = (170.584, 20.945) deg = (11 22 20, +20 56 42) (J2000)
There was no significant excess flux in the previous transit at UT 00:45 UT
and in the next transit at 03:54 UT with an upper limit of 20 mCrab for each.

Swift/XRT followup observations are requested. 


GRB_name: GRB200514B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27736
SUBJECT: GRB 200514B: Fermi GBM Final Real-time Localization
DATE:    20/05/14 09:17:53 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 SHORT GRB

At 09:07:37 UT on 14 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200514B (trigger 611140062.123856 / 200514380).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 238.3, Dec = 37.2 (J2000 degrees, equivalent to J2000 15h 53m, 37d 12'), with a statistical uncertainty of 13.1 degrees.

The angle from the Fermi LAT boresight is 63.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200514380/quicklook/glg_skymap_all_bn200514380.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200514380/quicklook/glg_healpix_all_bn200514380.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200514380/quicklook/glg_lc_medres34_bn200514380.gif


GRB_name: GRB200514B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27737
SUBJECT: GRB200514B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 611140062)
DATE:    20/05/14 18:20:05 GMT
FROM:    Tomas Ahumada at U. of Maryland  <tahumada@astro.umd.edu>

Tomas Ahumada (UMD), Shreya Anand (Caltech), Igor Andreoni (Caltech),
Michael Coughlin (UMN), Erik Kool (OKC), Simeon Reusch (DESY), Ana SaguÃ©s
Carracedo (OKC), Robert Stein (DESY)

on behalf of the Zwicky Transient Facility (ZTF) and Global Relay of
Observatories Watching Transients Happen (GROWTH) collaborations

We observed the localization region of the short GRB200514B (trigger
611140062) detected by the Gamma-Ray Burst Monitor (GBM) on the Fermi
satellite with the Palomar 48 inch telescope equipped with the 47 square
degree Zwicky Transient Facility (ZTF) camera. We obtained a series of g-
and r-band images covering 519.3 square degrees beginning at 10:01 UT on
2020 May 14 (0.9 hours after the burst trigger time). This corresponds to
~49% of the probability enclosed in the GRB localization map (GCN 27736).
Each exposure was 300s, reaching a g-band median depth of 21.8 mag and
r-band median depth of 22.0 mag. 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) and AMPEL
(Nordin et al. 2019). We required at least 2 detections separated by at
least 15 minutes to select against moving objects. Furthermore, we
cross-matched 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 no spatially
coincident ZTF alert to be issued before the detection time of the GBM
trigger. The candidates within the 90% probability contour of the GRB
localization map that passed the automatic selection criteria and human
vetting are presented in the table below.


+----------------------------------------------------------------------------------------------------+
| ZTF Name     | IAU Name   | RA (deg)    | DEC (deg)   | Filter | Mag   |
MagErr | MJD      | Notes |
+----------------------------------------------------------------------------------------------------+
| ZTF20aazpphd | AT 2020jww | 242.7149675 | +27.1616870 | r      | 19.6  |
0.05   | 58983.49 |       |
| ZTF20aazppnv | AT 2020jxa | 238.1438691 | +25.5764946 | r      | 21.1  |
0.17   | 58983.49 | (b,c) |
| ZTF20aazprjq | AT 2020jxb | 233.5213585 | +43.3298714 | r      | 21.3  |
0.13   | 58983.47 | (a,d) |
| ZTF20aazptlp | AT 2020jxd | 229.007524  | +48.774925  | r      | 21.5  |
0.19   | 58983.48 | (a,e) |
| ZTF20aazptnn | AT 2020jxc | 237.2967278 | +47.271954  | r      | 21.6  |
0.17   | 58983.48 | (a,f) |
| ZTF20aazpnst | AT 2020jxn | 254.0989833 | +34.4655542 | r      | 22.0  |
0.20   | 58983.47 | (a,g) |
| ZTF20aazpofi | AT 2020jxm | 236.929525  | +46.9809542 | r      | 21.5  |
0.13   | 58983.48 | (a,h) |
+----------------------------------------------------------------------------------------------------+

We highlight ZTF20aazpphd, as it is offset 12 arcseconds from the center of
a galaxy at 160 Mpc and was not detected 2.15 days earlier with a limiting
magnitude of g > 20.53. The host spectroscopic redshift is z = 0.04573,
which would imply a g-band absolute magnitude of -17.23.

Notes:
(a) Offset from faint host
(b) Nuclear
(c) SDSS photoz = 0.170 +- 0.03
(d) SDSS photoz = 0.226 +- 0.04
(e) SDSS photoz = 0.402 +- 0.11
(f) SDSS photoz = 0.261 +- 0.06
(g) SDSS photoz = 0.188 +- 0.05
(h) SDSS photoz = 0.464 +- 0.08


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).


GRB_name: GRB200514B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27738
SUBJECT: GRB200514B: ATLAS detections of ZTF20aazpphd  
DATE:    20/05/14 20:36:48 GMT
FROM:    Stephen Smartt at Queen's U/Belfast  <s.smartt@qub.ac.uk>

S. J. Smartt, K. W. Smith (QUB), S. Srivastav, T.-W. Chen (MPE), D. R.
Young, M. Fulton, (QUB) L. Denneau, H. Flewelling, A. Heinze, J.
Tonry, H. Weiland (IfA, Univ. Hawaii), A. Rest (STScI), B. Stalder
(LSST), C. Stubbs (Harvard), O. McBrien, J. Gillanders, D.
O'Neil, P. Clark (QUB)

The transient ZTF20aazpphd (AT2020jww) was reported by Ahumada et al.
(GCN 27737) at r = 19.6 +/- 0.05 within the localization region of the
short GRB200514B (trigger 611140062) detected by the Gamma-Ray Burst
Monitor (GBM) on the Fermi satellite at MJD = 58983.38029 (GCN 27736).

ATLAS, the twin telescope system on Haleakala and Mauna Loa was
observing this region of sky in normal sky operations (Tonry et al.
2018, PASP, 130f4505, Smith et al. 2020, arXiv:2003.09052). We detect
ZTF20aazpphd before the ZTF epoch at the following magnitudes :

ATLAS c-band :
MJD         dt   m     err 
58983.42278 +1.02 19.47 0.13
58983.42461 +1.06 19.18 0.20
58983.43478 +1.31 19.46 0.13
58983.43890 +1.41 19.42 0.21

where dt is the time in hrs since Fermi trigger. 

ZTF reported the r-band : 
58983.49    +2.63 19.6  0.05 

The first ATLAS detection is 1.61hrs before the ZTF in the cyan-band
(a composite g+r filter). The two magnitudes are consistent, given the
errors and the different filter profiles. Therefore there is no
evidence of any rapid decline within this short interval, as might be
expected for a sGRB afterglow. We also have non-detections of
ZTF20aazpphd 2 days before, hence it is more likely a young supernova.


GRB_name: GRB200514B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27739
SUBJECT: GRB 200514B: GROWTH-India follow-up of ZTF20aazpphd (AT2020jww)
DATE:    20/05/14 22:39:14 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar, V. Bhalerao(IITB), G. C. Anupama, S. Barway(IIA), U. Stanzin(IAO)
report on behalf of the GROWTH-India collaboration:


We observed ZTF20aazpphd (AT2020jww) reported by (T. Ahumada et al., GCN
27737, S. J. Smartt et al., GCN 27738) with 0.7m GROWTH-India telescope. We
obtained g band exposures starting at UT 20-05-14T17:22:52. The transient
was reported in GCN 27737 as a followup of the GRB200514B event detected by
Fermi GBM (GCN 27736).


We obtained the following photometric results:-

------------------------------------------------------------------

 MJD(Start)| T-T0(hrs) | Exposure(sec) | Filter | Mag |

------------------------------------------------------------------

 58983.724 |  8.25 | 600 | g | 19.20 +/- 0.04 |

 58983.732 |  8.44 | 600 | g | 19.15 +/- 0.04|

 58983.863 | 11.58 | 500 | g | 19.12 +/- 0.05 |

------------------------------------------------------------------

The transient is not fading like a GRB afterglow as per our observation in
the g band. Hence, seems unrelated to the GRB200514B event.

The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree
field of view, set up by the Indian Institute of Astrophysics and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).


GRB_name: GRB200514B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27740
SUBJECT: Optical transient ZTF20aazpphd is unrelated to GRB 200514B
DATE:    20/05/14 22:45:08 GMT
FROM:    Christian Malacaria at NASA-MSFC/USRA  <cmalacaria@usra.edu>

C. Malacaria (NASA/MSFC-USRA) and E. Burns (GSFC) report on behalf of the Fermi-GBM Team:

At 09:07:37 UT on 14 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) 
triggered and located GRB 200514B (GCN 27736, Fermi-GBM Team). 

Follow-up observations by the Zwicky Transient Facility identified ZTF20aazpphd 
as a potential optical counterpart to GRB 200514B (Ahumada et al., GCN 27737).
ZTF20aazpphd was subsequently observed by ATLAS, 
who found no evidence for rapid decline (Smartt et al., GCN 27738),
contrary to what expected for a short GRB afterglow.

We also verified that, when GBM triggered on GRB 200514B, the source position for 
ZTF20aazpphd as observed by GBM was occulted by Earth and therefore unobservable. 
We therefore conclude that the optical transient ZTF20aazpphd is unrelated to GRB 200514B.


GRB_name: GRB200514B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27741
SUBJECT: GRB200514B: YSE detection of ZTF20aazpphd
DATE:    20/05/14 23:00:35 GMT
FROM:    David Jones at UC,Santa Cruz  <david.jones@ucsc.edu>

D. O. Jones (UC Santa Cruz), K. D. French (Carnegie, Illinois), A. Agnello, C. R. Angus, Z. Ansari, N. Arendse, C. Gall, C. Grillo, S. H. Bruun, C. Hede, J. Hjorth, L. Izzo, H. Korhonen, S. Raimundo, D. Kodi Ramanah, A. Sarangi, R. Wojtak (DARK, U Copenhagen), K. Auchettl (DARK, UC Santa Cruz, U Melbourne), K. C. Chambers, M. E. Huber, E. A. Magnier, T. J. L. de Boer, J. R. Fairlamb, C. C. Lin, R. J. Wainscoat, T. Lowe, M. Willman, J. Bulger, A. S. B. Schultz (IfA, Hawaii), A. Engel, A. Gagliano, G. Narayan, M. Soraisam (Illinois), Q. Wang (JHU), A. Rest (JHU, STScI), S. J. Smartt, K. W. Smith (Queen's University Belfast), K. D. Alexander, A. Baldeschi, P. Blanchard, D. Coppejans, L. DeMarchi, A. Hajela, W. Jacobson-Galan, R. Margutti, D. Matthews, C. Stauffer, M. Stroh, G. Terreran (Northwestern), M. Drout (U Toronto), D. A. Coulter, G. Dimitriadis, R. J. Foley, T. Hung, C. D. Kilpatrick, C. Rojas-Bravo, M. R. Siebert (UC Santa Cruz), E. Ramirez-Ruiz (UC Santa Cruz, DARK)

The ZTF and ATLAS collaborations (Ahumada et al., GCN 27737; Smartt et al., GCN 27738) have both reported observations of ZTF20aazpphd (AT2020jww), a transient within the localization region of  short GRB200514B (trigger 611140062).  GRB200514B was detected at MJD = 58983.38029 by the Gamma-Ray Burst Monitor on the Fermi satellite (GCN 27736).

The Young Supernova Experiment (YSE; ATel 13330) also observed this region of the sky with Pan-STARRS1 on Haleakala (Chambers et al., 2016).  We detected ZTF20aazpphd in gi bands with an g-i color of -0.57 +/- 0.12 mag:

MJD           dt    band   mag     mag_err
58983.52303  +3.43  g_P1   19.197  0.079
58983.52573  +3.49  i_P1   19.766  0.094

The dt column is the time since GRB200514B was discovered in hours.  These measurements were taken 0.8 hours after the ZTF r-band observation, 1.75 hours after the ZTF g observation and 2.4 hours after ATLAS observations (Smartt et al., GCN 27738).  They are consistent with magnitudes from ZTF (g = 19.249 +/- 0.047) and ATLAS.  Our data do not show evidence for the rapid decline characteristic of a sGRB over the time baseline of ~2.4 hours.


GRB_name: GRB200512A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27742
SUBJECT: GRB 200512A: Swift-BAT refined analysis
DATE:    20/05/14 23:33:47 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. Sakamoto (AGU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
K. K. Simpson (PSU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (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 200512A (trigger #971846)
(Simpson et al., GCN Circ. 27726).  The BAT ground-calculated position is
RA, Dec = 7.417, -2.217 deg which is
   RA(J2000)  =  00h 29m 40.2s
   Dec(J2000) = -02d 13' 01.1"
with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 100%.

The mask-weighted light curve shows a single-pulse structure.
The main emission starts at ~T-3 s, peaks at ~T+3 s, and ends at
~T+40 s. In addition, there are some weak emission that lasts
until ~T+80 s. T90 (15-350 keV) is 74.0 +- 14.3 sec (estimated
error including systematics).

The time-averaged spectrum from T-2.86 to T+78.14 sec is best fit by a
simple
power-law model.  The power law index of the time-averaged spectrum is
1.68 +- 0.18.  The fluence in the 15-150 keV band is 8.1 +- 1.0 x 10^-7
erg/cm2.
The 1-sec peak photon flux measured from T+3.14 sec in the 15-150 keV band
is 0.4 +- 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/971846/BA/


GRB_name: GRB200514A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27743
SUBJECT: GRB 200514A: CALET Gamma-Ray Burst Monitor detection
DATE:    20/05/15 14:20:45 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

S. Ricciarini (U of Florence),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU),
P. S. Marrocchesi (U of Siena),
and the CALET collaboration:

The MAXI GRB 200514A (Okamoto et al., GCN Circ. 27735) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 02:21:11.346 UTC on 14 May 2020 (trigger
#1273457651). The burst signal was seen by all CGBM detectors.

The burst light curve shows a weak pulse which starts at T+1.6 sec and
ends at T+7.5 sec. The T90 and T50 durations measured by the SGM data are
5.1 +- 1.1 sec and 2.5 +- 1.1 sec (40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1273457651/

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


GRB_name: GRB200514A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27744
SUBJECT: GRB 200514A: MITSuME Akeno optical upper limits
DATE:    20/05/15 15:35:39 GMT
FROM:    Adachi Ryo at Tokyo Institute of Tech  <adachi@hp.phys.titech.ac.jp>

N. Nakamura, R. Hosokawa, R. Adachi, K. L. Murata, M. Niwano, F.
Ogawa, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the
MITSuME collaboration:

We performed tiling observation for the MAXI/GSC error region of GRB
200514A (Y. Okamoto et al., GCN Circular #27735; Ricciarini et al.,
GCN Circular #27743) with an optical tri-color (g', Rc, and Ic) camera
attached to the MITSuME 50cm telescopes at Akeno Observatory in Japan.

The follow up observation started at 2020-05-14 10:36:15 UT, 495
minutes after the trigger.

Our tiling observation covered almost ~65% of the MAXI/GSC error
region (GCN Circular #27735). Compared our co-added images with the
GSC2.3 and UCAC4 catalogs, we found no bright optical transient in the
observed region except a high proper motion star (R.A.=11:20:26.73,
Dec.=+19:53:14) listed in the NEOWISE/AllWISE high proper motion
objects (Schneider et al. 2016). Because the elevation of the target
field had dropped from 75 deg to 16 deg during the observations and
the sky condition was unstable, the obtained upper limits are
different for each field. The 5-sigma upper limits of the co-added
images are listed below.

Field num. | center position(R.A., Dec.) | size of field(R.A.(arcmin)
x Dec.(arcmin)) | 5-sigma upper limit | MID-UT(UT) | exposure
time(sec)
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Field 0 | 11:21:03, +19:43:24 | 24.9 x 25.9 | g' > 18.4, Rc > 18.2, Ic
> 16.5 | 12:24:50 14 May | 870
Field 1 | 11:19:53, +19:52:19 | 25.6 x 26.1 | g' > 18.0, Rc > 17.7, Ic
> 16.9 | 12:35:31 14 May | 480
Field 2 | 11:20:25, +19:26:36 | 25.8 x 25.9 | g' > 16.8, Rc > 16.7, Ic
> 16.1 | 12:44:04 14 May | 1170
Field 3 | 11:19:15, +19:35:00 | 25.7 x 26.0 | g' > 18.3, Rc > 17.9, Ic
> 17.1 | 12:05:44 14 May | 660
Field 4 | 11:21:41, +19:59:30 | 25.6 x 26.1 | g' > 17.8, Rc > 17.6, Ic
> 16.7 | 11:18:32 14 May | 360
Field 5 | 11:20:30, +20:08:15 | 25.6 x 25.9 | g' > 18.0, Rc > 17.4, Ic
> 16.8 | 12:33:09 14 May | 570
Field 6 | 11:19:49, +19:09:39 | 25.7 x 25.9 | g' > 18.7, Rc > 18.3, Ic
> 17.5 | 12:11:34 14 May | 660
Field 7 | 11:18:42, +19:18:54 | 25.7 x 26.1 | g' > 18.0, Rc > 17.6, Ic
> 16.8 | 11:26:50 14 May | 210
Field 8 | 11:21:55, +20:24:47 | 25.9 x 26.0 | g' > 17.1, Rc > 17.0, Ic
> 15.9 | 16:21:30 14 May | 150
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
We used the UCAC4 catalog for the flux calibration. The magnitudes are
expressed in the AB system. The images were processed in real-time
through the MITSuME GPU reduction pipeline (Niwano et al., in prep;
https://github.com/MNiwano/Eclair).


GRB_name: GRB200514B
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27745
SUBJECT: GRB 200514B: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 611140062) - More Candidates
DATE:    20/05/15 21:42:13 GMT
FROM:    Shreya Anand at GROWTH Caltech  <sanand@caltech.edu>

Simeon Reusch (DESY), Tomas Ahumada (UMD), Shreya Anand (Caltech), Michael Coughlin (UMN), Mansi M. Kasliwal (Caltech), Erik Kool (OKC), Harsh Kumar (IIT-B), Robert Stein (DESY), Igor Andreoni (Caltech), Varun Bhalerao (IIT-B), Albert Kong (NTHU) and Leo Singer (NASA/GSFC)
on behalf of the Zwicky Transient Facility (ZTF) and Global Relay of Observatories Watching Transients Happen (GROWTH) collaborations

We re-observed the localization region of the short GRB200514B (trigger 611140062) detected by the Gamma-Ray Burst Monitor (GBM) on the Fermi satellite with the Palomar 48 inch telescope equipped with the 47 square degree Zwicky Transient Facility (ZTF) camera. We obtained a series of g- and r-band images covering 570 square degrees beginning at 09:58 UT on 2020 May 15 (24.83 hours after the burst trigger time). This corresponds to ~71% of the probability enclosed in the Earth-occultation corrected GRB localization map (GCN 27736). Each exposure was 300s, reaching g-band and r-band median depths of 22.4 and 22.2 mag respectively. 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) and AMPEL (Nordin et al. 2019). 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. The candidates within the 90% probability contour of the GRB localization map that pass these selection criteria as well as human vetting are presented in the table below. The filter, magnitude and MJD columns correspond to the ZTF first alert, while the Decline Rate (D.R) is in [mag/day]. 

+----------------------------------------------------------------------------------------------------------------------+
| ZTF Name   | IAU Name  | RA (deg)  | DEC (deg) | Filter | Mag | MagErr | MJD   | D.R. [mag/day] | Notes  |
+----------------------------------------------------------------------------------------------------------------------+
| ZTF20aazplwp | AT 2020jzo | 234.0167814 | 41.1672761 |  r  | 21.6 | 0.15 | 58984.45 | 0.3 in g    | (a)   |
| ZTF20aazqlgx | AT 2020jzr | 246.0908608 | 34.6259478 |  r  | 22.3 | 0.19 | 58984.45 | 0.3 in r    | (c)(1)  |
| ZTF20aazphye | AT 2020jzn | 255.6577428 | 41.7013160 |  r  | 21.6 | 0.15 | 58984.47 | 0.3 in g    | (c,d)(2) |
| ZTF20aazpnxd | AT 2020kap | 255.931646 | 48.3862806 |  r  | 21.6 | 0.16 | 58984.47 | 0.3 in g    | (a)   |
| ZTF20aazpkri | AT 2020kaq | 240.7324792 | 48.5554957 |  r  | 21.3 | 0.10 | 58984.46 | 0       | (a)   |
| ZTF20aazqndp | AT 2020kal | 237.8212032 | 50.4933039 |  r  | 22.1 | 0.15 | 58984.46 | 0       | (c,d)(3) |
| ZTF20aazqpps | AT 2020kam | 252.2388065 | 41.3097433 |  r  | 21.6 | 0.14 | 58984.47 | 0       | (c,d)(4) |
+----------------------------------------------------------------------------------------------------------------------+


Notes:
(a) hostless
(b) offset from a galaxy
(c) nuclear
(d) PS1 detection at source position

(1) SDSS phot-z = 0.35 +/- 0.10
(2) SDSS phot-z = 0.26 +/- 0.04 
(3) CLU z = 0.03195
(4) SDSS phot-z = 0.2 +/- 0.03 

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).


GRB_name: GRB200514B
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27748
SUBJECT: GRB 200514B: BALROG localization (Fermi Trigger 611140062 / GRB 200514380)
DATE:    20/05/16 20:33:50 GMT
FROM:    Jochen Greiner at MPI  <jcg@mpe.mpg.de>

J.M. Burgess, J. Greiner, F. Berlato, B. Biltzinger, F. Kunzweiler (all MPE
Garching) report:

Given the interest in this GRB and the optical follow-up work, we
performed a more thorough analysis of the GRB 200514B with the BALROG
localization/spectral fitting method (Burgess et al. 2018, MNRAS 476, 1427;
Berlato et al. 2019, ApJ 873, 60), finding a localization of

  RA (2000.0) = 260 +/- 12
  Decl. (2000.0) = 58.8 +/- 6.8
  (1 sigma error). 
  
The Healpix map can be found at:
http://mpe.mpg.de/~jcg/grb200514B/GRB200514380_balrog_healpix.fits

Spectral analysis of the time interval T0 = -0.38 ... 0.58s with
the empirical Band function yields the following best-fit spectral
parameters:

 alpha = -0.63 +/- 0.30
 beta = -2.13 +/- 0.29
 Ep = 170 +/- 70 keV

with an energy flux of (3.5 +/-2) x 10^-7 erg/cm2/s in the 10-1000 keV band.


GRB_name: GRB200517A
Detection_method: MAXI Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27750
SUBJECT: GRB 200517A:  MAXI/GSC detection
DATE:    20/05/17 12:46:55 GMT
FROM:    Motoko Serino at RIKEN/MAXI  <motoko@crab.riken.jp>

M. Niwano (Tokyo Tech), H. Negoro (Nihon U.), M. Serino (AGU),
M. Nakajima, M. Aoki, K. Kobayashi, R. Takagi, K, Asakura, K, Seino, S. Mokumoto (Nihon U.),
T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN),
T. Sakamoto, S. Sugita, H. Nishida, A. Yoshida (AGU),
Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, Y. Okamoto, S. Kitakoga (Chuo U.),
M. Shidatsu (Ehime U.),
N. Kawai, R. Adachi (Tokyo Tech),
S. Nakahira, Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, M. Tominaga, T. Nagatsuka (JAXA),
Y. Ueda, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.),
H. Tsunemi (Osaka U.),
M. Yamauchi, K. Kurogi, K. Miike (Miyazaki U.),
T. Kawamuro (NAOJ),
K. Yamaoka (Nagoya U.),
Y. Kawakubo (LSU),
M. Sugizaki (NAOC) 
report on behalf of the MAXI team:

The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 11:27:21 UT .
We obtained the source position at
(R.A., Dec) = (17.230 deg, -50.745 deg) = (01 08 55, -50 44 41) (J2000)
with a rectangular error box with the following corners:
(15.411, -49.816) deg = (01 01 38, -49 48 57) (J2000)
(15.002, -50.346) deg = (01 00 00, -50 20 45) (J2000)
(18.572, -51.401) deg = (01 14 17, -51 24 03) (J2000)
(18.949, -50.859) deg = (01 15 47, -50 51 32) (J2000)
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 198 +- 33 mCrab
(4.0-10.0keV, 1 sigma error).
There was no significant excess flux in the previous transit at 09:54 UT
with an upper limit of 20 mCrab.


GRB_name: GRB200517A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27751
SUBJECT: GRB 200517A: Tiled Swift observations
DATE:    20/05/17 13:37:18 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 200517A. Automated analysis of the XRT data will
be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00090

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: GRB200514A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27753
SUBJECT: GRB 200514A: AstroSat CZTI detection
DATE:    20/05/18 14:27:20 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

The AstroSat CZT Imager recorded a transient event in all four of its Veto detectors, coincident with the GRB200514A reported by MAXI (Okamoto Y. et al., GCN #27735) and CALET (Ricciarini S. et al., GCN # 27743).  There was no significant detection in the main CZT detectors.  The sky location reported by MAXI was 155 deg away from the CZTI pointing axis, causing the Veto detectors to face the source. The peak of the light curve occurred at 2020-05-14 02:21:14.435 UT. We estimate a T90 of 9.64 sec from the combined Veto lightcurves.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200517A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27754
SUBJECT: GRB 200517A: Swift-XRT afterglow detection
DATE:    20/05/18 15:06:08 GMT
FROM:    Jeffrey Gropp at PSU  <jdg44@psu.edu>

B. Sbarufatti (PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester),
K.L. Page (U. Leicester), T. Sbarrato (INAF-OAB), P. D'Avanzo
(INAF-OAB), M.G. Bernardini (INAF-OAB), J. D. Gropp (PSU) and P.A.
Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the MAXI-detected
burst GRB 200517A (Niwano et al. GCN Circ. 27750) in a series of
observations tiled on the sky. The total exposure time is 1.1 ks,
distributed over 7 tiles; the maximum exposure at a single sky location
was 388 s. The data were collected between T0+8.0 ks and T0+8.3 ks, and
are entirely in Photon Counting (PC) mode. 

An uncatalogued X-ray source is detected and is above the RASS limit,
and is therefore likely the GRB afterglow. Using 366 s of PC mode data
and 2 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 = 17.69837, -50.92242 which is equivalent to:

RA (J2000): 01h 10m 47.61s
Dec(J2000): -50d 55' 20.7"

with an uncertainty of 3.3 arcsec (radius, 90% confidence). This
position is 20.7 arcmin from the MAXI position.  We cannot determine at
the present time whether the source is fading.

The results of the XRT-team automatic analysis of the likely afterglow
are at https://www.swift.ac.uk/xrt_products/TILED_GRB00090/Source1.php.
The results of the full analysis of the tiled XRT observations are
available at https://www.swift.ac.uk/xrt_products/TILED_GRB00090.

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


GRB_name: GRB200514B
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27755
SUBJECT: IPN triangulation of GRB 200514B (short)
DATE:    20/05/18 21:31:32 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

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

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
report:

The short-duration GRB 200514B
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 27736;
BALROG localization: Burgess et al., GCN Circ. 27748)
was detected by Fermi (GBM trigger 606799116),
INTEGRAL (SPI-ACS), and Konus-Wind in the waiting mode,
at about 32857 s UT (09:07:37).

We have triangulated it to a Konus-GBM annulus centerd at
RA(2000)=233.253 deg (15h 33m 01s) Dec(2000)=-18.040 deg (-18d 02' 24"),
whose radius is 79.909 +/- 20.599 deg (3 sigma), and
to a GBM-INTEGRAL annulus centered at
RA(2000)=209.576 deg (13h 58m 18s) Dec(2000)=+50.867 deg (+50d 52' 01"),
whose radius is 33.883 +/- 33.883 deg (3 sigma).

The IPN localization is consistent with, but reduces the area of
the Fermi-GBM ones (GCN 27736, GCN 27748).

This localization may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB200514_T32857/IPN


GRB_name: GRB200519A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27756
SUBJECT: GRB 200519A: Swift detection of a burst with an optical afterglow
DATE:    20/05/19 11:42:49 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

B. Sbarufatti (PSU), S. B. Cenko (GSFC), C. Gronwall (PSU),
J.D. Gropp (PSU), N. J. Klingler (PSU), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC) and K. L. Page (U Leicester) report on
behalf of the Neil Gehrels Swift Observatory Team:

At 11:20:23 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200519A (trigger=973140).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 255.334, -30.380 which is 
   RA(J2000) = 17h 01m 20s
   Dec(J2000) = -30d 22' 47"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 80 sec.  The peak count rate
was ~37000 counts/sec (15-350 keV), at ~23 sec after the trigger. 

The XRT began observing the field at 11:21:13.3 UT, 49.6 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 255.3327, -30.3782 which is equivalent to:
   RA(J2000)  = 17h 01m 19.85s
   Dec(J2000) = -30d 22' 41.5"
with an uncertainty of 4.7 arcseconds (radius, 90% containment). This
location is 7.6 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 1.36e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 57 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  = 17:01:20.00 = 255.33335
  DEC(J2000) = -30:22:40.9  = -30.37803
with a 90%-confidence error radius of about 0.61 arc sec. This position is 2.1
arc sec. from the center of the XRT error circle. The estimated magnitude is
15.38 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.47. 

Burst Advocate for this burst is B. Sbarufatti (bxs60 AT 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: GRB200519A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27757
SUBJECT: GRB 200519A: iTelescope optical afterglow detection
DATE:    20/05/19 16:37:18 GMT
FROM:    Albert Kong at NTHU  <akhkong@gmail.com>

A.K.H. Kong (NTHU, Taiwan) reports

We observed the field of GRB 200519A (Sbarufatti et al. GCN 27756)
with the T31 0.5m telescope of iTelescope.Net in Siding Spring,
Australia. The observation was done with a luminance filter (400-700
nm) beginning at 2020-05-19 15:07:45 UT (about 3.8 hours after the
trigger) for 300 sec. The optical afterglow (Sbarufatti et al. GCN
27756) was detected with an estimated magnitude of 19.3+/-0.8 by
calibrating with the USNO UCAC5 catalogue.


GRB_name: GRB200517A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27758
SUBJECT: Fermi GBM Sub-Threshold Detection of GRB 200517A
DATE:    20/05/19 16:46:54 GMT
FROM:    Cori Fletcher at USRA  <cfletcher@usra.edu>

C. Fletcher (USRA) reports on behalf of the Fermi-GBM Team:

MAXI/GSC detected GRB 200517A at 11:27:21 UT (GCN 27750). There was no
Fermi-GBM onboard trigger around the event.

An automated, blind search for short gamma-ray bursts below the onboard
triggering threshold in Fermi-GBM identified no counterparts.

The GBM targeted search [1], the most sensitive, coherent search for
GRB-like signals identified a transient most significantly on the 8.192 s
timescale, with a log likelihood ratio of 13 and a location consistent with
the MAXI/GSC event. The GBM targeted search event was found with the highest
significance with a "soft" spectrum (Band function with Epeak=70 keV, alpha=-1.9,
beta=-3.7) for a GRB.


[1] Goldstein et al. 2019 arXiv:1903.12597


GRB_name: GRB200519A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27759
SUBJECT: GRB 200519A: LCO Optical Afterglow Detection
DATE:    20/05/19 17:04:42 GMT
FROM:    Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>

R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:

We observed Swift GRB 200519A (Sbarufatti et al., GCN 27756) with the LCO 1-m Sinistro instrument at the Siding Spring Observatory Australia site, on May 9, from 12:39 to 13:02 UT (corresponding to 1.05 to 1.38 hours from the GRB trigger time) with the Bessel R and I filters.

We performed a series of 5x120s exposures in R and I. We detect an optical source in stacked images at the UVOT afterglow candidate position position.  Using the USNO-B.1 catalog as reference, we calculate the following magnitudes:

R = 17.07 +/- 0.02

I = 16.69 +/- 0.02

These magnitudes are not corrected for galactic extinction.

R.S. is funded by NSF AST grant #1831682


GRB_name: GRB200519A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27760
SUBJECT: GRB 200519A: BOOTES-3/YA optical counterpart observations
DATE:    20/05/19 21:41:56 GMT
FROM:    Youdong HU at IAA-CSIC  <youdong@iaa.es>

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC), I. 
Carrasco and C. Perez del Pulgar (Univ. de Malaga), M. D. 
Caballero-Garcia (ASU-CAS, CZ) and R. Querel (NIWA), on behalf of a 
larger collaboration, report:

The 60cm BOOTES-3/YA robotic telescope at NIWA Lauder in Otago (New 
Zealand) automatically responded to the Swift trigger of GRB 200519A 
(Sbarufatti et al. GCNC 27756). The first image (clear filter) were 
obatined starting at 11:20:57 UT (~ 34 s after trigger). At the position 
reported by Swift/UVOT (Sbarufatti et al. GCNC 27756), we found the 
optical counterpart with a magnitude of 14.96+-0.12 mag in the 1s 
exposure image whose median time at 52s that also reported by iTelescope 
(Kong et al. GCNC 27757) and LCO (Strausbaugh et al. GCNC 27759), which 
calibrated with nearby stars in USNO-B 1.0 catalog. Further analysis is 
ongoing.

We thank the staff at NIWA for its excellent support.


GRB_name: GRB200519A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27761
SUBJECT: GRB 200519A: Enhanced Swift-XRT position
DATE:    20/05/19 22:12:54 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 832 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 200519A, 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 = 255.33318, -30.37824 which is equivalent
to:

RA (J2000): 17h 01m 19.96s
Dec (J2000): -30d 22' 41.7"

with an uncertainty of 1.8 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: GRB200519A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27763
SUBJECT: GRB 200519A: Swift-XRT refined Analysis
DATE:    20/05/19 23:42:47 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), A.P. Beardmore (U. Leicester), P. D'Avanzo (INAF-OAB), M.G.
Bernardini (INAF-OAB), E. Ambrosi  (INAF-IASFPA) , J. D. Gropp (PSU),
J.A. Kennea (PSU) and B. Sbarufatti report on behalf of the Swift-XRT
team:

We have analysed 8.2 ks of XRT data for GRB 200519A (Sbarufatti et al.
GCN Circ. 27756), from 42 s to 35.4 ks after the  BAT trigger. The data
comprise 970 s in Windowed Timing (WT) mode (the first 5 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Osborne et
al. (GCN Circ. 27761).

The light curve can be modelled with a power-law decay with a decay
index of alpha=1.16 (+/-0.05).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.902 (+/-0.029). The
best-fitting absorption column is  4.35 (+0.17, -0.16) x 10^21 cm^-2,
in excess of the Galactic value of 3.3 x 10^21 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 1.75 (+/-0.08) and a
best-fitting absorption column of 4.7 (+/-0.5) x 10^21 cm^-2. The
counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 4.7 x 10^-11 (6.6 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      4.7 (+/-0.5) x 10^21 cm^-2
Galactic foreground: 3.3 x 10^21 cm^-2
Excess significance: 4.4 sigma
Photon index:      1.75 (+/-0.08)

If the light curve continues to decay with a power-law decay index of
1.16, the count rate at T+24 hours will be 0.11 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.1 x
10^-12 (7.1 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/00973140.

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


GRB_name: GRB200519A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27764
SUBJECT: GRB 200519A: 1.3m DFOT Optical Afterglow Detection
DATE:    20/05/20 01:58:43 GMT
FROM:    Amit Kumar at ARIES, India  <amitkundu515@gmail.com>

A. Kumar (ARIES), S. B. Pandey (ARIES), K. Chand (ARIES), A. Aryan (ARIES),
R. Gupta (ARIES), A. Ghosh (ARIES), Dimple (ARIES), and K. Misra (ARIES)
report:

We observed the optical afterglow of the Swift detected GRB 200519A (GCN
27756, GCN 27761 and GCN 27763) with the 1.3m Devsthal Fast Optical
Telescope (DFOT) at
Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital
(India), from 2020-05-19T19:17:27 to 2020-05-19T22:01:38 UTC.
We observed 11 frames each of 300 seconds in Bessell R filter, whereas, a
serious of 7x300 seconds exposure in Bessell I filter.
In the stacked images, we clearly detected the optical afterglow of GRB
200519A in both Bessell R and I filters within the Swift XRT enhanced error
circle (Osborne et al. GCN 27761).
The estimated magnitudes are consistent with optical detections by Kong et
al. GCN 27757, Strausbaugh et al. GCN 27759, and Hu et al. 27760.


The observed magnitudes are as follows:

T_start-T0 (hours)   Start Date (UTC)              Filter
 Magnitudes (mag)
---------------------------------------------------------------------------------------------------------------
7.95               2020-05-19T19:17:27                 R               19.4
+- 0.1
9.98               2020-05-19T21:19:27                 I
18.2 +- 0.1


Photometry is done based on the USNO-B1.0 catalog. The quoted magnitudes
are not corrected for Galactic extinction.


GRB_name: GRB200519A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27765
SUBJECT: Swift GRB 200519A: Global MASTER-Net observations report 
DATE:    20/05/20 05:38:25 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200519A ( B. Sbarufatti et al., GCN 27756) errorbox  23275 sec after notice time and 23295 sec after trigger time at 2020-05-19 17:48:38 UT, with upper limit up to  17.0 mag. The observations began at zenith distance = 75 deg. The sun  altitude  is -25.5 deg. 

MASTER-OAFA robotic telescope  located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB 200519A errorbox  46397 sec after notice time and 46416 sec after trigger time at 2020-05-20 00:14:00 UT, with upper limit up to  16.6 mag. The observations began at zenith distance = 69 deg. The sun  altitude  is -31.7 deg. 

The galactic latitude b =  7 deg., longitude l = 354 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1360465

We obtain a following upper limits.  

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

   23385 |         MASTER-SAAO |   C |   180 | 16.9 |        
   23385 |         MASTER-SAAO |   C |   180 | 16.2 |        
   24012 |         MASTER-SAAO |   C |   180 | 17.0 |        
   24012 |         MASTER-SAAO |   C |   180 | 16.6 |        
   46507 |         MASTER-OAFA |   C |   180 | 16.6 |        
   47353 |         MASTER-OAFA |   C |   180 | 16.5 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200519A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27766
SUBJECT: GRB 200519A: AstroSat CZTI detection
DATE:    20/05/20 09:38:42 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200519A, which was also detected by Swift (Sbarufatti B. et al., GCN #27756), iTelescope (Kong A.et al., GCN # 27757), LCO (Strausbaugh R. et al., GCN # 27759), BOOTES-3/YA (Hu Y. et al., GCN # 27760), 1.3m DFOT (Kumar A. et al., GCN # 27764) and Global MASTER-Net (Lipunov V. et al., GCN # 27765).

The source was clearly detected in the 40-200 keV energy range. Of the ~80-second duration reported by Swift/BAT, CZTI detected only the brightest segment peaking at 2020-05-19 11:20:46.500 UT. The measured peak count rate associated with the burst is 983 +/- 39 cts/s above the background in the combined data of four quadrants, with a total of 3616 +/- 17 cts. The local mean background count rate was 519 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 8.46 +/- 0.05 s.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed a single peak of emission peaking at 2020-05-19 11:20:46.000 UT. The measured peak count rate is 2339 +/- 62 cts/s above the background in the combined Veto data of four quadrants, with a total of 8499 +/- 21 cts. The local mean background count rate was 1541 +/- 1 cts/s.  We measure a T90 of 8.64 +/- 0.02 s from the cumulative Veto light curve.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200519A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27767
SUBJECT: GRB 200519A: GROWTH-India optical follow-up
DATE:    20/05/20 16:32:17 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar, V. Bhalerao(IITB), G. C. Anupama, S. Barway, J. Stanzin (IIA)
report on behalf of the GROWTH-India collaboration:

We followed up GRB200519A (R. Sbarufatti et al., GCN 27756, A. Kong et al., GCN
27757, R. Strausbaugh et al., GCN 27759, Y. Hu et al., GCN 27760, A Kumar
et al., GCN 27764) with 0.7m GROWTH-India telescope. We obtained 600-sec
exposures in SDSS g, r, i filters starting at UT 20-05-19T17:11:06 (~5.85
hrs after the burst).

We obtained the following magnitudes with PSF photometry, calibrated
against PanSTARRs PS1 data release (Flewelling et al., 2018).

------------------------------------------------------------------

 JD(Start) | T-T0(hrs) | Filter | Mag |

------------------------------------------------------------------

2458989.216 | 5.85 | g | 19.926 +/- 0.09

2458989.321 | 8.36 | g | 20.514 +/- 0.09

2458989.354 | 9.16 | g | 20.779 +/- 0.13

2458989.281 | 7.41 | r | 19.359 +/- 0.07

2458989.305 | 7.98 | r | 19.505 +/- 0.06

2458989.329 | 8.56 | r | 19.788 +/- 0.06

2458989.361 | 9.33 | r | 19.891 +/- 0.08

2458989.265 | 7.02 | i | 19.529 +/- 0.12

2458989.313 | 8.17 | i | 19.984 +/- 0.14

2458989.369 | 9.52 | i | 20.206 +/- 0.18

2458989.392 | 10.07| i | 20.583 +/- 0.26

------------------------------------------------------------------

We found that the source is fading with a power-law of 1.65 +/- 0.28 in g
band, 2.36 +/- 0.4 using in r band and 2.37 +/- 0.33 in i band observations.

The magnitudes are not corrected for galactic extinction.

The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree
field of view, set up by the Indian Institute of Astrophysics and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).


GRB_name: GRB200519A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27769
SUBJECT: GRB 200519A: Swift/UVOT Detection
DATE:    20/05/20 19:09:27 GMT
FROM:    Mike Siegel at PSU/Swift MOC  <mhs18@psu.edu>

M. H. Siegel (PSU) and B. Sbarufatti (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200519A
58 s after the BAT trigger (Sbarufatti et al., GCN Circ. 27756).
A source consistent with the XRT position
(Sbarufatti et al. GCN Circ. 27756)
is detected in the initial UVOT exposures.

The preliminary UVOT position is:
  RA  (J2000) =  17:01:20.01 = 255.33337 (deg.)
  Dec (J2000) = -30:22:41.1  = -30.37808 (deg.)
with an estimated uncertainty of 0.42 arc sec. (radius, 90% confidence).

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               58          208          147         15.43 +/- 0.02
v                  599          619           20         16.30 +/- 0.16
b                  525          545           19         17.13 +/- 0.13
u                  270          519          246         16.27 +/- 0.04
w1                 648          840           39         17.46 +/- 0.25
w2                 747          766           19        >17.5

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.47 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200519A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27770
SUBJECT: GRB 200519A: Insight-HXMT/HE detection
DATE:    20/05/21 02:10:25 GMT
FROM:    Shuo Xiao at IHEP  <xiaoshuo@ihep.ac.cn>

GRB 200519A: Insight-HXMT/HE detection

S. Xiao, Y. G. Zheng, C. Cai, Y. F. Du, W. C. Xue, 
Q. Luo, Q. B. Yi, Y. Huang, C. K. Li, G. Li, 
X. B. Li, J. Y. Liao, S. L. Xiong,C. Z. Liu, 
X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, 
X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), 
T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, 
M. Wu, Y. P. Xu, S. N. Zhang (IHEP), 
report on behalf of the Insight-HXMT team:

At 2020-05-19T11:20:23.73 (T0), Insight-HXMT/HE detected 
GRB 200519A (trigger ID: HEB200519472) in a routine search of the data, 
which also triggered Swift/BAT (GCN #27756).

The Insight-HXMT/HE light curve mainly consists of multiple 
pulses with a duration (T90) of 8.97 s measured from T0+19.85 s. 
The 1-ms peak rate, measured from T0+23.18 s, is 1206 cnts/sec. 
The total counts from this burst is 4010 counts. 
URL_LC: http://twiki.ihep.ac.cn/twiki/viewfile/HXMT/GRBList?filename=HEB200519472_lc.jpg;rev=2

All measurements above are made with the CsI detectors operating in the 
normal mode with the energy range of about 80-800 keV (deposited energy). 
Only gamma-rays with energy greater than about 200 keV can penetrate 
the spacecraft and leave signals in the CsI detectors installed inside 
of the telescope. 

Insight-HXMT is the first Chinese space X-ray telescope, which was 
funded jointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information about it could be found at: 
http://www.hxmt.org.


GRB_name: GRB200519A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27771
SUBJECT: GRB 200519A: Swift-BAT refined analysis
DATE:    20/05/21 03:38:57 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

M. Stamatikos (OSU), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), B. Sbarufatti (PSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-61 to T+242 sec from the recent telemetry
downlink,
we report further analysis of BAT GRB 200519A (trigger #973140)
(Sbarufatti et al., GCN Circ. 27756).  The BAT ground-calculated position is
RA, Dec = 255.319, -30.393 deg which is
   RA(J2000)  =  17h 01m 16.6s
   Dec(J2000) = -30d 23' 35.6"
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 99%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~T0 and ends at ~T+100 s. The three main peaks occur at ~T+1 s, ~T+24 s,
and ~T+75 s, respectively. T90 (15-350 keV) is 71.88 +- 1.28 sec (estimated
error including systematics).

The time-averaged spectrum from T-0.45 to T+103.00 sec is best fit
by a simple power-law model.  The power law index of the time-averaged
spectrum is 1.42 +- 0.03.  The fluence in the 15-150 keV band
is 1.2 +- 0.02 x 10^-05 erg/cm2. The 1-sec peak photon flux measured
from T+23.53 sec in the 15-150 keV band is 20.6 +- 0.5 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/973140/BA/


GRB_name: GRB200519A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27772
SUBJECT: GRB 200519A: R-band follow-up from HCT
DATE:    20/05/21 10:52:29 GMT
FROM:    Brajesh Kumar at Indian Inst. of Astrophysics  <brajesh.kumar@iiap.res.in>

Brajesh Kumar, Anirban Dutta, Avinash Singh, G. C. Anupama, D. K. Sahu 
and Pramod Kumar (IIA, Bengaluru)

We observed the optical afterglow of GRB 200519A (Sbarufatti et al., GCN 
27756) with the 2-m Himalayan Chandra Telescope (HCT) located at the 
Indian Astronomical Observatory, Hanle, India. The observations started 
on 2020-05-19 (20:10:35 UT) under good sky conditions and three 
consecutive frames (120, 240, and 240 sec) in Bessell R-band were 
obtained. The OT candidate (Kong et al., GCN 27757, Strausbaugh et al., 
GCN 27759, Hu et al., GCN 27760, Kumar et al., GCN 27764, Kumar et al. 
GCN 27767, Siegel & Sbarufatti, GCN 27769) is clearly detected in each 
frame. The preliminary photometry is performed relative to the USNO-B1.0 
catalogue. The initial magnitude of the OT is 19.70 +- 0.10 (uncorrected 
for the galactic extinction).

We thank the observing staff at IAO and CREST for helping with the 
observations.


GRB_name: GRB200519A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27773
SUBJECT: GRB 200519A: CALET Gamma-Ray Burst Monitor detection
DATE:    20/05/21 14:03:23 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

P. S. Marrocchesi (U of Siena),
A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U),
N. Cannady (GSFC/UMBC), M. L. Cherry (LSU),
S. Ricciarini (U of Florence),
and the CALET collaboration:

The Swift GRB 200519A (Swift detection: Sbarufatti et al.,
GCN Circ. 27756, Stamatikos et al., GCN Circ. 27771;
AstroSat CZTI detection: Gupta et al., GCN Circ. 27766;
Insight-HXMT/HE detection: GCN Circ. 27770;
https://gcn.gsfc.nasa.gov/other/200519A.gcn3) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 11:20:43.755 UTC on 19 May 2020 (trigger
#1273922014: http://cgbm.calet.jp/cgbm_trigger/flight/1273922014/).
The burst signal was seen mainly by the SGM detector. The source location
was outside the FOV of the HXM detectors.

The burst light curve shows a double-peaked pulse which starts at T-2.0 sec,
peaks at T+4.4 sec and ends at T+5.9 sec. The T90 and T50 durations
measured by the SGM data are 6.9 +- 1.5 sec and 3.3 +- 1.9 sec (40-1000
keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1273922014/

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


GRB_name: GRB200514B
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27774
SUBJECT: GRB 200514B: Fermi GBM observation
DATE:    20/05/21 15:37:06 GMT
FROM:    Elisabetta Bissaldi at INFN,Bari  <elisabetta.bissaldi@ba.infn.it>

E. Bissaldi (Politecnico and INFN Bari), C. Malacaria (NASA/MSFC-USRA),
S. Poolakil (UAH) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:


"At 09:07:37.12 UT on 14 May 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 200514B (trigger 611140062 / 200514380).
The GBM on-ground location was reported in GCN #27736 and is consistent
with the position triangulated by the IPN (Svinkin et al., 2020, GCN #27755).

The angle from the Fermi LAT boresight at the GBM trigger time is 63 degrees.

The GBM light curve shows a structured emission episode
with a duration (T90) of about 1.7 s (50-300 keV).
The time-averaged spectrum from T0-0.380 s to T0+0.260 s is
adequately fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.06 +/- 0.11 and
the cutoff energy, parameterized as Epeak, is 1700 +/- 900 keV.

The event fluence (10-1000 keV) in this time interval is
(4.8 +/- 0.6)E-07 erg/cm^2. The 64-ms peak photon flux measured
starting from T0-0.32 s in the 10-1000 keV band
is 3.1 +/- 0.8 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: GRB200517A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27775
SUBJECT: GRB 200517A: Swift-XRT Confirmation of afterglow
DATE:    20/05/21 16:04:22 GMT
FROM:    Jeffrey Gropp at PSU  <jdg44@psu.edu>

J. Gropp (PSU) reports on behalf of the Swift-XRT team:

We provide an update on the XRT light curve evolution of the candidate
X-ray afterglow of GRB 200517A (GCN Circ. 27750).

The XRT light curve now comprises data up to 300 ks from the MAXI trigger
(GCN Circs. 27750). There is a firm indication of fading with respect to
the first observation as reported previously (GCN Circ 27754), with a decay
index of 1.04 (+0.21, -0.18). We thus confirm that this is indeed the
afterglow of GRB 200517A.
The latest results can be viewed via:
https://www.swift.ac.uk/xrt_curves/00020993/

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


GRB_name: GRB200521A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27776
SUBJECT: GRB 200521A: AGILE/MCAL and ratemeters detection
DATE:    20/05/21 18:02:57 GMT
FROM:    Francesco Verrecchia at SSDC,INAF-OAR  <francesco.verrecchia@ssdc.asi.it>

F. Verrecchia (SSDC, and INAF/OAR), A. Ursi (INAF/IAPS), M. Tavani
(INAF/IAPS, and Univ. Roma Tor Vergata), M. Cardillo, C. Casentini,
G. Piano (INAF/IAPS),  F. Lucarelli, C. Pittori (SSDC, and INAF/OAR),
A. Bulgarelli, V. Fioretti, N. Parmiggiani (INAF/OAS-Bologna), M. Pilia
(INAF/OA-Cagliari), F. Longo (Univ. Trieste, and INFN Trieste), report
on behalf of the AGILE Team:

The AGILE satellite detected the short burst GRB 200521A that triggered
the automatic AGILE Mini-CALorimeter (MCAL) GRB alert Notice (ID
512427408), published at:
https://gcn.gsfc.nasa.gov/agile_mcal.html.

The event was detected by MCAL at T0 = 2020-05-21 12:16:40.00 +/- 0.01
(UT), and lasted about 0.16 s and released a total number of ~795 counts
in the detector (in the 0.4-100 MeV energy range), above an average
background rate of 771 counts / s.
The event is also visible in the scientific ratemeters of the SuperAGILE
(SA; 20-60 keV), Anti-Coincidence (AC; 80-200 keV), and MCAL (0.4-100 MeV)
detectors.

The MCAL light curve can be found at:
http://www.agilescienceapp.it/notices/GRB_067901-067901_517148200.741647.png 
.

The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the
energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress.


GRB_name: GRB200521A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27777
SUBJECT: GRB 200521A: CALET Gamma-Ray Burst Monitor detection
DATE:    20/05/22 09:52:36 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

A. Yoshida, T. Sakamoto, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (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 bright short hard GRB 200521A (AGILE/MCAL and ratemeters detection:
Verrecchia et al., GCN Circ. 27776) triggered the CALET Gamma-ray Burst
Monitor (CGBM) at 12:16:40.803 UTC on 21 May 2020.
The burst signal was seen by all CGBM detectors.
Because of a problem in one of the ground alert processing script, the GCN
notice was not distributed automatically for this event.

The burst light curve shows a bright pulse which starts at T-0.304 sec,
peaks at -0.016 sec and ends at T+0.056 sec. The T90 and T50 durations
measured by the SGM data are 0.240 +- 0.094 sec and 0.104 +- 0.018 sec
(40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1274098167/

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


GRB_name: GRB200522A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27778
SUBJECT: GRB 200522A: Swift detection of a short burst
DATE:    20/05/22 12:02:37 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

P. A. Evans (U Leicester), J.D. Gropp (PSU),
S. Laha (GSFC/UMBC/CRESST), A. Y. Lien (GSFC/UMBC) and
K. L. Page (U Leicester) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 11:41:34 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200522A (trigger=973628).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 5.667, -0.282 which is 
   RA(J2000) = 00h 22m 40s
   Dec(J2000) = -00d 16' 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 1 sec.  The peak count rate
was ~5000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 11:42:57.5 UT, 83.4 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 5.6823, -0.2824 which
is equivalent to:
   RA(J2000)  = 00h 22m 43.76s
   Dec(J2000) = -00d 16' 56.7"
with an uncertainty of 3.9 arcseconds (radius, 90% containment). This
location is 55 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.  We
cannot determine whether the source is fading at the present time. 

A power-law fit to a spectrum formed from promptly downlinked event
data does not constrain the column density. 

No UVOT analysis is available at this time. 

Burst Advocate for this burst is P. A. Evans (pae9 AT star.le.ac.uk). 
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: GRB200522A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27779
SUBJECT: GRB 200522A: Coincident catalogued galaxy at z~0.4
DATE:    20/05/22 14:05:54 GMT
FROM:    Wen-fai Fong at Northwestern U  <wfong@northwestern.edu>

W. Fong, K. Paterson (Northwestern) and E. Berger (Harvard) report:

"We searched the location of the short GRB 200522A (GCN 27778; Evans et al.) in the SDSS DR12 and PS1-3Pi surveys at the XRT afterglow candidate position. The current XRT position fully encompasses a catalogued galaxy in both SDSS and PS1-3Pi, with a position of RA = 0:22:43.717, Dec = -0:16:57.52 (Alam et al. 2015, Chambers et al. 2016). This galaxy has SDSS magnitudes* of u = 22.55, g = 22.11, r = 21.17, i = 20.87, z = 20.69 mag. The SDSS photometric redshift estimate is z_phot = 0.4 +/- 0.1.

Adopting r=21.17 mag and the XRT positional uncertainty, we estimate a probability of chance coincidence of ~0.01. If the association to this galaxy is correct, pending the precise position of the GRB afterglow, this would place GRB 200522A in lower 35% of the Swift short GRB redshift distribution (c.f., Fong et al. 2017, Gompertz et al. 2020).

Follow-up, where possible, is highly encouraged."


* Information pulled from SDSS: http://skyserver.sdss.org/DR12//en/tools/explore/summary.aspx?id=1237663783662977850


GRB_name: GRB200522A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27780
SUBJECT: GRB 200522A: Enhanced Swift-XRT position
DATE:    20/05/22 14:37:45 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 235 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 200522A, 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 = 5.68182, -0.28273 which is equivalent
to:

RA (J2000): 00h 22m 43.64s
Dec (J2000): -00d 16' 57.8"

with an uncertainty of 3.2 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: GRB200522B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27781
SUBJECT: GRB 200522B: Fermi GBM Final Real-time Localization
DATE:    20/05/22 15:47:03 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 15:36:39 UT on 22 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200522B (trigger 611854604.46714 / 200522650).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 87.0, Dec = -39.8 (J2000 degrees, equivalent to J2000 05h 47m, -39d 47'), with a statistical uncertainty of 4.4 degrees.

The angle from the Fermi LAT boresight is 41.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200522650/quicklook/glg_skymap_all_bn200522650.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200522650/quicklook/glg_healpix_all_bn200522650.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200522650/quicklook/glg_lc_medres34_bn200522650.gif


GRB_name: GRB200522B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27782
SUBJECT: Fermi GRB 200522B: Global MASTER-Net observations report 
DATE:    20/05/22 17:45:15 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200522B ( Fermi GBM team, GCN 27781) errorbox  3363 sec after notice time and 3389 sec after trigger time at 2020-05-22 16:33:08 UT, with upper limit up to  19.4 mag. Observations started at twilight.  The observations began at zenith distance = 48 deg. The sun  altitude  is -10.2 deg. 

The galactic latitude b = -28 deg., longitude l = 246 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1363163

We obtain a following upper limits.  

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

    3419 | 2020-05-22 16:33:08 |         MASTER-SAAO | (05h 58m 45.28s , -39d 59m 55.0s) |   C |    60 | 17.5 |        
    3419 | 2020-05-22 16:33:08 |         MASTER-SAAO | (05h 49m 22.12s , -40d 01m 28.5s) |   C |    60 | 17.4 |        
    3499 | 2020-05-22 16:34:28 |         MASTER-SAAO | (05h 48m 37.14s , -38d 01m 17.6s) |   C |    60 | 17.5 |        
    3499 | 2020-05-22 16:34:28 |         MASTER-SAAO | (05h 39m 28.89s , -38d 02m 50.7s) |   C |    60 | 17.5 |        
    3579 | 2020-05-22 16:35:48 |         MASTER-SAAO | (05h 48m 20.22s , -42d 00m 33.7s) |   C |    60 | 17.7 |        
    3579 | 2020-05-22 16:35:48 |         MASTER-SAAO | (05h 38m 38.91s , -42d 02m 06.3s) |   C |    60 | 17.7 |        
    3659 | 2020-05-22 16:37:08 |         MASTER-SAAO | (05h 37m 49.53s , -39d 59m 44.9s) |   C |    60 | 17.8 |        
    3659 | 2020-05-22 16:37:08 |         MASTER-SAAO | (05h 28m 25.89s , -40d 01m 16.6s) |   C |    60 | 17.8 |        
    3738 | 2020-05-22 16:38:27 |         MASTER-SAAO | (05h 58m 42.70s , -40d 00m 39.9s) |   C |    60 | 18.0 |        
    3738 | 2020-05-22 16:38:27 |         MASTER-SAAO | (05h 49m 18.66s , -40d 02m 11.8s) |   C |    60 | 18.1 |        
    3818 | 2020-05-22 16:39:47 |         MASTER-SAAO | (05h 48m 41.82s , -37d 59m 14.3s) |   C |    60 | 18.0 |        
    3818 | 2020-05-22 16:39:47 |         MASTER-SAAO | (05h 39m 33.79s , -38d 00m 45.5s) |   C |    60 | 18.1 |        
    3898 | 2020-05-22 16:41:07 |         MASTER-SAAO | (05h 48m 14.17s , -41d 59m 59.7s) |   C |    60 | 18.1 |        
    3898 | 2020-05-22 16:41:07 |         MASTER-SAAO | (05h 38m 32.84s , -42d 01m 30.8s) |   C |    60 | 18.4 |        
    3977 | 2020-05-22 16:42:26 |         MASTER-SAAO | (05h 37m 46.32s , -39d 59m 25.4s) |   C |    60 | 18.0 |        
    3977 | 2020-05-22 16:42:26 |         MASTER-SAAO | (05h 28m 22.56s , -40d 00m 55.9s) |   C |    60 | 18.5 |        
    4057 | 2020-05-22 16:43:46 |         MASTER-SAAO | (06h 08m 59.53s , -37d 59m 32.4s) |   C |    60 | 18.2 |        
    4057 | 2020-05-22 16:43:46 |         MASTER-SAAO | (05h 59m 51.12s , -38d 01m 03.1s) |   C |    60 | 18.6 |        
    4137 | 2020-05-22 16:45:06 |         MASTER-SAAO | (06h 09m 47.52s , -42d 00m 18.2s) |   C |    60 | 18.4 |        
    4137 | 2020-05-22 16:45:06 |         MASTER-SAAO | (06h 00m 05.69s , -42d 01m 49.1s) |   C |    60 | 18.8 |        
    4616 | 2020-05-22 16:53:05 |         MASTER-SAAO | (06h 08m 54.09s , -38d 00m 28.3s) |   C |    60 | 17.3 |        
    4616 | 2020-05-22 16:53:05 |         MASTER-SAAO | (05h 59m 51.83s , -38d 01m 56.4s) |   C |    60 | 19.2 |        
    4696 | 2020-05-22 16:54:25 |         MASTER-SAAO | (06h 09m 54.67s , -41d 58m 45.8s) |   C |    60 | 17.0 |        
    4696 | 2020-05-22 16:54:25 |         MASTER-SAAO | (06h 00m 08.45s , -42d 00m 13.7s) |   C |    60 | 19.1 |        
    4776 | 2020-05-22 16:55:45 |         MASTER-SAAO | (05h 59m 17.96s , -35d 59m 57.0s) |   C |    60 | 17.5 |        
    4776 | 2020-05-22 16:55:45 |         MASTER-SAAO | (05h 50m 19.06s , -36d 01m 25.2s) |   C |    60 | 19.0 |        
    4855 | 2020-05-22 16:57:04 |         MASTER-SAAO | (05h 59m 52.29s , -43d 58m 27.2s) |   C |    60 | 17.4 |        
    4855 | 2020-05-22 16:57:04 |         MASTER-SAAO | (05h 49m 46.12s , -43d 59m 55.1s) |   C |    60 | 19.4 |        
    4935 | 2020-05-22 16:58:24 |         MASTER-SAAO | (05h 39m 37.90s , -36d 00m 31.1s) |   C |    60 | 15.1 |        
    4935 | 2020-05-22 16:58:24 |         MASTER-SAAO | (05h 30m 39.02s , -36d 01m 57.3s) |   C |    60 | 18.9 |        
    5015 | 2020-05-22 16:59:44 |         MASTER-SAAO | (05h 28m 20.07s , -38d 01m 39.6s) |   C |    60 | 17.9 |        
    5015 | 2020-05-22 16:59:44 |         MASTER-SAAO | (05h 19m 06.88s , -38d 03m 08.5s) |   C |    60 | 19.1 |        
    5300 | 2020-05-22 17:04:29 |         MASTER-SAAO | (05h 59m 17.69s , -35d 59m 29.9s) |   C |    60 | 15.9 |        
    5300 | 2020-05-22 17:04:29 |         MASTER-SAAO | (05h 50m 26.98s , -36d 01m 00.2s) |   C |    60 | 18.6 |        
    5380 | 2020-05-22 17:05:49 |         MASTER-SAAO | (05h 59m 51.30s , -43d 59m 59.0s) |   C |    60 | 17.9 |        
    5380 | 2020-05-22 17:05:49 |         MASTER-SAAO | (05h 49m 53.77s , -44d 01m 33.0s) |   C |    60 | 19.2 |        
    5459 | 2020-05-22 17:07:08 |         MASTER-SAAO | (05h 30m 43.23s , -36d 01m 05.5s) |   C |    60 | 18.8 |        
    5539 | 2020-05-22 17:08:28 |         MASTER-SAAO | (05h 28m 17.98s , -38d 00m 41.6s) |   C |    60 | 17.8 |        
    5539 | 2020-05-22 17:08:28 |         MASTER-SAAO | (05h 19m 12.94s , -38d 02m 13.1s) |   C |    60 | 19.0 |        
    5619 | 2020-05-22 17:09:48 |         MASTER-SAAO | (05h 37m 34.00s , -43d 59m 09.8s) |   C |    60 | 17.7 |        
    5619 | 2020-05-22 17:09:48 |         MASTER-SAAO | (05h 27m 36.81s , -44d 00m 35.0s) |   C |    60 | 19.1 |        
    5698 | 2020-05-22 17:11:07 |         MASTER-SAAO | (05h 26m 48.04s , -42d 00m 36.7s) |   C |    60 | 17.9 |        
    5698 | 2020-05-22 17:11:07 |         MASTER-SAAO | (05h 17m 09.84s , -42d 01m 59.3s) |   C |    60 | 18.7 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200522A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27783
SUBJECT: GRB 200522A: Swift/UVOT Upper Limits
DATE:    20/05/22 21:43:20 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

N. P. M. Kuin (UCL-MSSL) and P. A. Evans (U. Leicester)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200522A
448 s after the BAT trigger (Evans et al., GCN Circ. 27778).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 27778) 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           448          598          147         >19.5
white              448          598          147         >19.5
v                  605          624           19         >17.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.03 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200522A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27784
SUBJECT: GRB 200522A: BOOTES-3/YA optical upper limit
DATE:    20/05/22 21:56:43 GMT
FROM:    Youdong HU at IAA-CSIC  <youdong@iaa.es>

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC), I. 
Carrasco and C. Perez del Pulgar (Univ. de Malaga), M. D. 
Caballero-Garcia (ASU-CAS, CZ) and R. Querel (NIWA), on behalf of a 
larger collaboration,
report:

The 60cm BOOTES-3/YA robotic telescope at NIWA Lauder in Otago (New 
Zealand) responded to the Swift trigger of GRB 200522A (Evans et al. 
GCNC 27778). The first image (clear filter) was obatined at high airmass 
starting at 18:31:37 UT(~ 6.8 hr after trigger). In the co-added image 
(15 exposures 60s each), no source is found at the position reported by 
Swift/XRT (Beardmore et al. GCNC 27780) down to 18.2 mag. Further 
observations are ongoing.

We thank the staff at NIWA for its excellent support.


GRB_name: GRB200522A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27785
SUBJECT: GRB 200522A: Swift-XRT refined Analysis
DATE:    20/05/22 22:43:15 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A.P. Beardmore (U. Leicester), E. Ambrosi  (INAF-IASFPA) , M. Capalbi
(INAF-IASFPA), M. Perri (ASDC), J.A. Kennea (PSU), A. Tohuvavohu (U.
Toronto), B. Sbarufatti (PSU), J.P. Osborne (U. Leicester) and P.A.
Evans report on behalf of the Swift-XRT team:

We have analysed 6.1 ks of XRT data for GRB 200522A (Evans et al. GCN
Circ. 27778), from 406 s to 35.1 ks after the  BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Beardmore et al. (GCN Circ. 27780).

The light curve can be modelled with a power-law decay with a decay
index of alpha=0.64 (+0.13, -0.14).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.6 (+0.5, -0.4). The
best-fitting absorption column is  6 (+14, -4) x 10^20 cm^-2,
consistent with the Galactic value of 2.9 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 4.3 x 10^-11 (4.7 x
10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      6 (+14, -4) x 10^20 cm^-2
Galactic foreground: 2.9 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:      1.6 (+0.5, -0.4)

If the light curve continues to decay with a power-law decay index of
0.64, the count rate at T+24 hours will be 3.9 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x
10^-13 (1.8 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/00973628.

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


GRB_name: GRB200522A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27786
SUBJECT: GRB 200522A: 6 GHz VLA radio source detection
DATE:    20/05/23 02:51:30 GMT
FROM:    Wen-fai Fong at Northwestern U  <wfong@northwestern.edu>

G. Schroeder, W. Fong, and K. D. Alexander (Northwestern) report:

"We observed the position of GRB 200522A (Evans et al., GCN 27778; Beardmore et al., GCN 27780) with the Karl G. Jansky Very Large Array (VLA) beginning on 2020 May 22.709 UT (5.33 hr post-burst) at a mean frequency of 6 GHz.

We detect a faint radio source with a significance of ~4-sigma at the position:

RA(J2000) = 00:22:43.72
Dec(J2000) = -00:16:57.9

with an uncertainty of ~1" in each coordinate. This position is consistent with the putative host galaxy (Fong et al., GCN 27779), and toward the outskirts of the updated XRT position. Further observations are planned to understand the nature of this source and whether it is the radio afterglow or emission from the host galaxy.

We thank the VLA staff immensely for quickly approving and executing these observations."


GRB_name: GRB200522A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27789
SUBJECT: Swift GRB 200522A: Global MASTER-Net observations report 
DATE:    20/05/23 07:06:17 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200522A ( P. A. Evans et al., GCN 27778) errorbox  52336 sec after notice time and 52358 sec after trigger time at 2020-05-23 02:14:12 UT, with upper limit up to  19.7 mag. The observations began at zenith distance = 73 deg. The sun  altitude  is -40.2 deg. 

The galactic latitude b = -62 deg., longitude l = 109 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1363025

We obtain a following upper limits.  

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

   52448 |         MASTER-SAAO |   C |   180 | 17.1 |        
   52448 |         MASTER-SAAO |   C |   180 | 17.4 |        
   53065 |         MASTER-SAAO |   C |   180 | 16.4 |        
   53065 |         MASTER-SAAO |   C |   180 | 17.3 |        
   53265 |         MASTER-SAAO |   C |   180 | 16.4 |        
   53265 |         MASTER-SAAO |   C |   180 | 16.9 |        
   55058 |         MASTER-SAAO |   C |    60 | 19.3 |        
   55138 |         MASTER-SAAO |   C |    60 | 19.3 |        
   55278 |         MASTER-SAAO |   C |   180 | 19.7 |        
   55697 |         MASTER-SAAO |   C |    60 | 19.1 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200521A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27790
SUBJECT: CGBM-SPI-ACS triangulation of short GRB 200521A
DATE:    20/05/23 13:27:33 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

T. Sakamoto, A. Yoshida, V. Pal'shin, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (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:


Using the CALET Gamma-Ray Burst Monitor (CGBM) event data and
publicly available INTEGRAl-SPI-ACS light curve data we have triangulated
the bright short hard GRB 200521A (AGILE/MCAL and ratemeters detection:
Verrecchia et al., GCN Circ. 27776; CGBM detection: Yoshida et al.,
GCN Circ. 27777) to a preliminary CGBM-SPI-ACS annulus centered at
RA(J2000)=86.570 deg (05h 46m 17s) Dec(J2000)= -34.390 deg (-34d 23' 24"),
whose radius is 88.32(-1.63,+1.63) deg (3 sigma).

The CGBM response also suggests the burst source was in the FOV of the
CGBM HXM detectors, i.e. within 60 deg from RA, Dec(J2000) = 112.49 deg,
+5.67 deg (=the center of the FOV).

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

The INTEGRAL-SPI-ACS data used in this analysis were obtained from
the INTEGRAL data archive through 
http://isdc.unige.ch/~savchenk/spiacs-online/
maintained by Volodymyr Savchenko.


GRB_name: GRB200522A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27792
SUBJECT: GRB 200522A: LCO Optical Afterglow Detection
DATE:    20/05/23 18:07:14 GMT
FROM:    Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>

R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:

We observed Swift GRB 200522A (Evans et al., GCN 27778) with the LCO 1-m Sinistro instrument at the South African Astronomical Observatory site, on May 23, from 03:20 to 04:20 UT (corresponding to 15.65 to 16.65 hours from the GRB trigger time) with the Bessel R and I filters.

We performed a series of 5x180s exposures in R and I. We detect an optical source in R band, but not I band, in stacked images at the Swift XRT enhanced position (Beardmore et al., GCN 27780).  Using the USNO-B.1 catalog as reference, we calculate the following magnitude and upper limit:

R = 21.49 +/- 0.16

I > 20.39

These magnitudes are not corrected for galactic extinction.

R.S. is funded by NSF AST grant #1831682

[GCN OPS NOTE(23may20):  See Circular 27794 for a correction.]


GRB_name: GRB200522A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27793
SUBJECT: GRB 200522A: Swift-BAT refined analysis
DATE:    20/05/23 21:14:23 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

T. N. Ukwatta (LANL), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), P. A. Evans (U Leicester),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), 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 200522A (trigger #973628)
(Evans et al., GCN Circ. 27778).  The BAT ground-calculated position is
RA, Dec = 5.668, -0.264 deg which is
   RA(J2000)  =  00h 22m 40.3s
   Dec(J2000) = -00d 15' 49.9"
with an uncertainty of 1.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 86%.

The mask-weighted light curve shows a multi-peaked structure that starts
at ~ T-0.3 s and ends at ~T+0.7 s. The main peak occur at ~T0. T90 (15-350
keV)
is 0.62 +- 0.08 sec (estimated error including systematics).

The time-averaged spectrum from T-0.02 to T+0.67 sec is best fit by
a simple power-law model.  The power law index of the time-averaged
spectrum is 1.45 +- 0.17.  The fluence in the 15-150 keV band is
1.1 +- 0.1 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from
T-0.17 sec in the 15-150 keV band is 1.5 +- 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/973628/BA/


GRB_name: GRB200522A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27794
SUBJECT: GRB 200522A: Correction to GCN 27792
DATE:    20/05/23 21:26:23 GMT
FROM:    Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>

R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:

Upon further analysis, the LCO observations reported in GCN 27792 clearly show two possible sources consistent with the XRT enhanced position (Beardmore et al., GCN 27780).
One source is located at ra, dec=(00:22:43.66,-00:16:58.59), 0.72 arc seconds from the center of the XRT enhanced position. The magnitudes of this source are the following:

R = 22.57 +/- 0.29
I > 20.39

A second source, which is located at ra, dec=(00:22:43.69,-00:16:57.37), 1.08 arcesonds from the center of the XRT localization is likely consistent with the potential host galaxy and magnitude were reported in GCN 27792.

At this moment it is not possible to determine if any of these objects is related to the short GRB 200522A, but further observations have been scheduled to determine possible variability.

We apologize for any confusion our earlier analysis may have caused.

R.S. is funded by NSF AST grant #1831682


GRB_name: GRB200521A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27795
SUBJECT: IPN triangulation of GRB 200521A (short)
DATE:    20/05/23 22:36:52 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

and

A. Ursi, N. Parmiggiani, F. Verrecchia, A. Bulgarelli,
A. Trois, M. Marisaldi, C. Pittori, M. Tavani, Y. Evangelista,
I. Donnarumma, M. Cardillo, G. Piano, G. Minervini, A. Argan,
F. Lucarelli, A. Zoli, V. Fioretti, F. Fuschino, M. Pilia,
F. Longo, A. Giuliani on behalf of the AGILE team, report:

The short-duration GRB 200521A
(AGILE detection: Verrecchia et al., GCN Circ. 27776;
CALET-GBM detection: Yoshida et al., GCN Circ. 27777;
CGBM-SPI-ACS triangulation: Sakamoto et al., GCN Circ. 27790)
has been detected by AGILE (MCAL, SuperAGILE, Anti-Coincidence),
CALET (GBM), Konus-Wind, and INTEGRAL (SPI-ACS), so far,
at about 44201 s UT (12:16:41).

We have triangulated it to a preliminary, 3 sigma error box
whose coordinates are:
  ---------------------------------------------
   RA(2000), deg                 Dec(2000), deg
  ---------------------------------------------
  Center:
   169.531 (11h 18m 07s)  +7.222 ( +7d 13' 20")
  Corners:
   168.785 (11h 15m 08s)  +5.440 ( +5d 26' 23")
   170.087 (11h 20m 21s)  +9.279 ( +9d 16' 45")
   170.289 (11h 21m 09s)  +8.994 ( +8d 59' 37")
   168.987 (11h 15m 57s)  +5.152 ( +5d 09' 08")
  ---------------------------------------------
The error box area is 1.14 sq. deg, and its maximum
dimension is 4.27 deg (the minimum one is 16.9 arcmin).
The Sun distance was about 106 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB200521_T44201/IPN/

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


GRB_name: GRB200521A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27796
SUBJECT: Konus-Wind detection of short/hard GRB 200521A
DATE:    20/05/23 22:45:12 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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

The short GRB 200521A
(AGILE detection: Verrecchia et al., GCN Circ. 27776;
CALET-GBM detection: Yoshida et al., GCN Circ. 27777;
CGBM-SPI-ACS triangulation: Sakamoto et al., GCN Circ. 27790;
IPN triangulation: Svinkin et al., GCN Circ. 27795)
triggered Konus-Wind (KW) at T0=44201.268 s UT (12:16:41.268).

The light curve of the burst shows a single pulse
with a total duration of ~0.3 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200521_T44201/

As observed by Konus-Wind, the burst had
a fluence of (1.28 +/- 0.15)x10^-5 erg/cm^2 and
a 16-ms peak energy flux, measured from T0+0.080 s,
of (7.38 +/- 0.87)x10^-5 erg/cm^2/s
(both in the 20 keV - 10 MeV energy range).

The spectrum of the burst (measured from T0 to T0+0.256 s)
is well fitted in the 20 keV - 15 MeV range
by a cutoff power-law (CPL) function with the following model
parameters: the photon index alpha = -0.26(-0.16,+0.18),
and the peak energy Ep = 1358(-170,+196) keV, chi2 = 46/61 dof.
Fitting this spectrum with a GRB (Band) function yields
nearly the same alpha and Ep, and an upper limit on beta of -2.7.

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.


GRB_name: GRB200524A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27797
SUBJECT: GRB 200524A: Fermi-LAT detection
DATE:    20/05/24 14:49:12 GMT
FROM:    Masanori Ohno at Hiroshima University  <ohno@astro.hiroshima-u.ac.jp>

F. Fana Dirirsa (Univ. of Johannesburg), M. Axelsson (KTH & Stockholm
Univ.), M. Ohno (Hiroshima Univ.), F. Piron (CNRS/IN2P3/LUPM) and F. Longo
(University and INFN, Trieste) report on behalf of the Fermi-LAT
Collaboration:

On May 24, 2020, Fermi-LAT detected high-energy emission from
GRB 200524A, which was also detected by Fermi-GBM (trigger 611989445).

At the time of the trigger (T0 = 05:04:00.36 UT) Fermi-LAT was passing
through the SAA, and observations started at roughly
T0+110 seconds. The GRB is detected at high energy (>100 MeV) by Fermi-LAT
at a location of:

RA, Dec = 212.8, 61.0 (degrees, J2000) with an error radius of 0.2 deg (90%
containment, statistical error only).

This was ~25 deg from the LAT boresight when observations started
(T0+110s), and is ~3 deg from the GBM final ground position.

The photon flux above 100 MeV in the time interval 110-900 s after the GBM
trigger is 2.2e-06 +/- 0.8e-06 ph/cm2/s. The estimated photon index above
100 MeV is -1.7 +/ - 0.2. The highest-energy photon is a 9.2 GeV event
which is observed 748 seconds after the GBM trigger. After ~T0+900s, the
GRB location moved outside the LAT FoV.

A Swift ToO has been approved for this burst.

The Fermi-LAT point of contact for this burst is
Feraol Fana Dirirsa (fdirirsa@uj.ac.za ).

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: GRB200524A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27798
SUBJECT: GRB 200524A: Swift ToO observations
DATE:    20/05/24 15:15:41 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

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

Swift has initiated a ToO observation of the Fermi/LAT GRB 200524A. 
Automated analysis of the XRT data will be presented online at
https://www.swift.ac.uk/ToO_GRBs/00021001

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 Fermi/LAT 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: GRB200524A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27799
SUBJECT: ZTF Discovery of ZTF20abbiixp: The Likely Optical Afterglow to GRB 200524A
DATE:    20/05/24 18:47:58 GMT
FROM:    Anna Ho at Caltech  <annayqho@gmail.com>

Anna Y. Q. Ho, Yuhan Yao (Caltech), Daniel A. Perley (LJMU) report on
behalf of the Zwicky Transient Facility collaboration:

The Zwicky Transient Facility (ZTF, Bellm et al. 2019, Graham et al. 2019)
discovered ZTF20abbiixp, a fast transient at
14h12m10.33s +60d54m19.0s (J2000)
213.043037 +60.905288 (J2000)
as part of the ZTF Uniform Depth Survey (Goldstein et al. in prep).

ZTF20abbiixp was first detected at r~17.4 mag on UT 2020-05-24T06:52:07 and
faded by 0.3 mag over the next 30 minutes, with a total of four
observations showing continuous fading. The last non-detection was 24 hours
prior (2020-05-23T06:43:03) with a limiting magnitude of r>20.4 mag. There
is no counterpart in ZTF reference images down to a limiting magnitude of
r>22.90.

We searched the GCN archive and determined that ZTF20abbiixp is in the
error circle of GRB 200524A, which was detected by Fermi-GBM and Fermi-LAT
(GCN 27797). The position of ZTF20abbiixp is 0.151 degrees offset from the
LAT position, within the 0.2 degree error radius (90% containment).

The time of GRB 200524A was 1.802 hours prior to the first detection of
ZTF20abbiixp. We conclude that ZTF20abbiixp is very likely to be the GRB
afterglow.

Follow-up observations are highly encouraged.

ZTF is a project led by PI S. R. Kulkarni at Caltech (see ATEL #11266), and
includes IPAC; WIS, Israel; OKC, Sweden; JSI/UMd, USA; UW,USA; DESY,
Germany; NRC, Taiwan; UW Milwaukee, USA and LANL USA. ZTF acknowledges the
generous support of the NSF under AST MSIP Grant No 1440341. Alert
distribution service provided by DIRAC@UW. Alert filtering is being
undertaken by the GROWTH marshal system, supported by NSF PIRE grant
1545949.


GRB_name: GRB200524A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27800
SUBJECT: GRB 200524A: GROWTH-India confirmation of optical afterglow
DATE:    20/05/24 19:58:19 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar, V. Bhalerao(IITB), G. C. Anupama, S. Barway, U. Stanzin (IIA)
report on behalf of the GROWTH-India collaboration:

We followed up GRB 200524A (F. F. Dirirsa et al., GCN 27797, A. Ho et al.,
GCN 27799) with 0.7m GROWTH-India telescope. We obtained 600-sec exposures
in SDSS g, r, i filters starting at UT 2020-05-24T10:41:57 (~5.6 hrs after
the burst). We detect a faint transient with magnitudes r = 20.56 +- 0.14
and i = 20.59 +- 0.28 (calibrated against PanSTARRs PS1 data release,
Flewelling
et al., 2018). The source position matches with the likely afterglow
candidate by A. Ho et al. (GCN 27799). The fading rate is approximately 3
magnitudes in four hours, consistent with the fading rate reported in the
ZTF GCN. We hereby, confirm ZTF20abbiixp as the afterglow of GRB 200524A.

We obtained the following photometric results:-

------------------------------------------------------------------

 JD(Start) | T-T0(hrs) | Filter | Mag |

------------------------------------------------------------------

2458993.946 | 5.64 | g | > 21.01 (5-sigma)

2458993.954 | 5.83 | r | 20.56 +/- 0.14

2458993.962 | 6.02 | i | 20.59 +/- 0.28

------------------------------------------------------------------

Given the fast fading, we encourage the followup of the source. The
magnitudes are not corrected for galactic extinction.

The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree
field of view, set up by the Indian Institute of Astrophysics and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).

[GCN OPS NOTE(24may20):  Please see Circular 27804 for a correction to this Circular.]


GRB_name: GRB200524A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27801
SUBJECT: Fermi GRB 200524A: Global MASTER-Net observations report 
DATE:    20/05/24 20:45:10 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

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




MASTER-IAC robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 200524A ( F. Fana Dirirsa et al., GCN 27797) errorbox  74 sec after notice time and 111 sec after trigger time at 2020-05-24 05:05:51 UT, with upper limit up to  17.9 mag. Observations started at twilight.  The observations began at zenith distance = 67 deg. The sun  altitude  is -13.1 deg. 

MASTER-Tavrida robotic telescope  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 200524A errorbox  47446 sec after notice time and 47483 sec after trigger time at 2020-05-24 18:15:23 UT, with upper limit up to  18.9 mag. Observations started at twilight.  The observations began at zenith distance = 22 deg. The sun  altitude  is -10.0 deg. 

The galactic latitude b = 53 deg., longitude l = 110 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1364553

We obtain a following upper limits.  

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

     121 | 2020-05-24 05:05:51 |          MASTER-IAC | (13h 54m 44.48s , +64d 23m 18.5s) |  P| |    20 | 16.4 |        
     121 | 2020-05-24 05:05:51 |          MASTER-IAC | (13h 52m 51.72s , +64d 28m 46.4s) |  P- |    20 | 16.2 |        
     202 | 2020-05-24 05:07:06 |          MASTER-IAC | (14h 05m 35.11s , +64d 25m 10.2s) |  P| |    30 | 16.5 |        
     262 | 2020-05-24 05:07:06 |          MASTER-IAC | (14h 05m 35.11s , +64d 25m 10.3s) |  P| |   150 | 17.4 |  Coadd 
     447 | 2020-05-24 05:07:06 |          MASTER-IAC | (14h 05m 35.11s , +64d 25m 10.2s) |  P| |   520 | 17.5 |  Coadd 
     202 | 2020-05-24 05:07:06 |          MASTER-IAC | (14h 03m 42.26s , +64d 30m 39.9s) |  P- |    30 | 16.6 |        
     262 | 2020-05-24 05:07:06 |          MASTER-IAC | (14h 03m 42.26s , +64d 30m 39.9s) |  P- |   150 | 17.7 |  Coadd 
     447 | 2020-05-24 05:07:06 |          MASTER-IAC | (14h 03m 42.26s , +64d 30m 39.9s) |  P- |   520 | 17.9 |  Coadd 
     298 | 2020-05-24 05:08:33 |          MASTER-IAC | (14h 05m 41.22s , +64d 25m 34.8s) |  P| |    50 | 16.8 |        
     298 | 2020-05-24 05:08:33 |          MASTER-IAC | (14h 03m 48.47s , +64d 31m 05.3s) |  P- |    50 | 17.0 |        
     417 | 2020-05-24 05:10:22 |          MASTER-IAC | (14h 05m 37.30s , +64d 26m 44.3s) |  P| |    70 | 16.7 |        
     417 | 2020-05-24 05:10:22 |          MASTER-IAC | (14h 03m 44.58s , +64d 32m 15.1s) |  P- |    70 | 17.0 |        
     555 | 2020-05-24 05:12:30 |          MASTER-IAC | (14h 05m 37.10s , +64d 25m 14.7s) |  P| |    90 | 16.7 |        
     695 | 2020-05-24 05:12:30 |          MASTER-IAC | (14h 05m 37.10s , +64d 25m 14.7s) |  P| |   370 | 17.2 |  Coadd 
     555 | 2020-05-24 05:12:30 |          MASTER-IAC | (14h 03m 44.50s , +64d 30m 45.6s) |  P- |    90 | 17.0 |        
     695 | 2020-05-24 05:12:30 |          MASTER-IAC | (14h 03m 44.49s , +64d 30m 45.6s) |  P- |   370 | 17.7 |  Coadd 
     720 | 2020-05-24 05:15:00 |          MASTER-IAC | (14h 05m 40.33s , +64d 26m 43.7s) |  P| |   120 | 16.6 |        
     720 | 2020-05-24 05:15:00 |          MASTER-IAC | (14h 03m 47.66s , +64d 32m 14.6s) |  P- |   120 | 17.0 |        
     922 | 2020-05-24 05:18:02 |          MASTER-IAC | (14h 05m 33.40s , +64d 26m 06.3s) |  P| |   160 | 16.4 |        
     922 | 2020-05-24 05:18:02 |          MASTER-IAC | (14h 03m 40.77s , +64d 31m 37.6s) |  P- |   160 | 16.6 |        
    1151 | 2020-05-24 05:21:41 |          MASTER-IAC | (14h 05m 33.93s , +64d 27m 05.4s) |  P| |   180 | 15.8 |        
    1151 | 2020-05-24 05:21:41 |          MASTER-IAC | (14h 03m 41.21s , +64d 32m 36.9s) |  P- |   180 | 16.4 |        
    1331 | 2020-05-24 05:21:41 |          MASTER-IAC | (14h 03m 41.17s , +64d 32m 36.9s) |  P- |   540 | 16.5 |  Coadd 
    1391 | 2020-05-24 05:25:41 |          MASTER-IAC | (14h 05m 40.44s , +64d 26m 04.0s) |  P| |   180 | 15.3 |        
    1391 | 2020-05-24 05:25:41 |          MASTER-IAC | (14h 03m 47.80s , +64d 31m 35.5s) |  P- |   180 | 15.8 |        
    1629 | 2020-05-24 05:29:39 |          MASTER-IAC | (14h 03m 42.61s , +64d 30m 34.8s) |  P- |   180 | 15.5 |        
   47513 | 2020-05-24 18:15:23 |      MASTER-Tavrida | (14h 04m 04.92s , +62d 01m 07.4s) |   C |    60 | 17.4 |        
   47594 | 2020-05-24 18:16:44 |      MASTER-Tavrida | (13h 50m 59.78s , +64d 00m 37.7s) |   C |    60 | 17.6 |        
   47675 | 2020-05-24 18:18:05 |      MASTER-Tavrida | (13h 29m 49.44s , +62d 00m 37.3s) |   C |    60 | 17.6 |        
   47756 | 2020-05-24 18:19:25 |      MASTER-Tavrida | (13h 44m 19.15s , +60d 01m 24.6s) |   C |    60 | 17.8 |        
   47836 | 2020-05-24 18:20:46 |      MASTER-Tavrida | (14h 03m 58.14s , +62d 02m 08.5s) |   C |    60 | 17.8 |        
   48129 | 2020-05-24 18:25:38 |      MASTER-Tavrida | (14h 18m 44.20s , +62d 08m 50.8s) |   C |    60 | 18.1 |        
   48209 | 2020-05-24 18:26:59 |      MASTER-Tavrida | (13h 48m 27.80s , +64d 10m 01.2s) |   C |    60 | 18.3 |        
   48290 | 2020-05-24 18:28:19 |      MASTER-Tavrida | (14h 06m 45.51s , +64d 11m 10.3s) |   C |    60 | 18.2 |        
   48451 | 2020-05-24 18:31:01 |      MASTER-Tavrida | (13h 44m 38.52s , +62d 11m 16.6s) |   C |    60 | 18.4 |        
   48531 | 2020-05-24 18:32:21 |      MASTER-Tavrida | (13h 42m 06.69s , +60d 10m 42.5s) |   C |    60 | 18.5 |        
   48612 | 2020-05-24 18:33:41 |      MASTER-Tavrida | (13h 58m 09.72s , +60d 11m 28.6s) |   C |    60 | 18.8 |        
   48693 | 2020-05-24 18:35:03 |      MASTER-Tavrida | (14h 18m 50.75s , +62d 10m 04.4s) |   C |    60 | 18.6 |        
   48773 | 2020-05-24 18:36:23 |      MASTER-Tavrida | (14h 06m 42.74s , +64d 09m 24.8s) |   C |    60 | 18.7 |        
   48854 | 2020-05-24 18:37:44 |      MASTER-Tavrida | (13h 44m 37.74s , +62d 10m 11.8s) |   C |    60 | 18.9 |        
   48935 | 2020-05-24 18:39:04 |      MASTER-Tavrida | (13h 58m 12.40s , +60d 11m 28.7s) |   C |    60 | 18.8 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200524A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27802
SUBJECT: GRB 200524A: CrAO observations of ZTF20abbiixp
DATE:    20/05/24 20:53:20 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

V. Rumyantsev (CrAO), A. Pozanenko (IKI),  S. Belkin (IKI), E. Mazaeva 
(IKI), A. Volnova (IKI) report on behalf of IKI-GRB-FuN:

We observed Fermi-LAT detected GRB 200524A (Dirirsa et al., GCN 27797) 
with   ZTSh 2.6m telescope of CrAO starting on 2020-05-24 (UT) 19:35:16. 
We clearly detected the OT discovered by ZTF (Ho et al., GCN 27799); see 
also Kumar et al. (GCN 27800). The R magnitude of the OT is 20.1 +/- 0.2 
at the time of the first exposure. Observations and data reduction is 
ongoing.


GRB_name: GRB200524A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27803
SUBJECT: GRB 200524A: 3.6m DOT observations of the afterglow candidate ZTF20abbiixp
DATE:    20/05/24 21:50:57 GMT
FROM:    Kuntal Misra at ARIES,India  <kuntal@aries.res.in>

Pankaj Sanwal, Kuntal Misra, Ankur Ghosh, Dimple, Amit Kumar, Amar Aryan, Rahul Gupta, S. B. Pandey, Brijesh Kumar, T. S. Kumar and Amitesh Omar (ARIES) report on behalf of the GRB collaboration:


We observed the field of GRB 200524A (Fana Dirirsa et al., GCN 27797) with the 3.6m Devasthal Optical Telescope (DOT) located in Devasthal, India on 2020-05-24T19:18:00 (UT) using the recently commissioned ADFOSC instrument.  We observed a sequence of 300 sec images in g, r and i bands.  We clearly detect the optical transient discovered by ZTF  (Ho et al., GCN 27799) and also reported by Kumar et al. (GCN 27800) and Rumyantsev et al. (GCN 27802).   In the first r band image the afterglow has a r band magnitude of 21.1+/-0.03.  Further processing of the data is in progress.  


GRB_name: GRB200524A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27804
SUBJECT: GRB 200524A: Correction to the GCN 27800
DATE:    20/05/24 21:53:38 GMT
FROM:    Harsh Kumar at Indian Inst of Tech,Bombay  <harshkosli13@gmail.com>

H. Kumar, V. Bhalerao(IITB), G. C. Anupama, S. Barway, U. Stanzin (IIA)
report on behalf of the GROWTH-India collaboration:

We mistakenly reported the wrong observation time in our previous GCN
27800. We deeply apologize for the confusion caused.

Here is the corrected GCN:-
-----------------------------------------------------------------

We followed up GRB 200524A (F. F. Dirirsa et al., GCN 27797, A. Ho et al.,
GCN 27799) with 0.7m GROWTH-India telescope. We obtained 600-sec exposures
in SDSS g, r, i filters starting at UT 2020-05-24T16:11:57 (~11.11 hrs
after the burst). We detect a faint transient with magnitudes r = 20.56 +/-
0.14 and i = 20.59 +/- 0.28 (calibrated against PanSTARRs PS1 data
release, Flewelling
et al., 2018). The source position matches with the likely afterglow
candidate by A. Ho et al. (GCN 27799). The fading rate is approximately 3
magnitudes in ~9.4 hours, consistent with the fading rate reported in the
ZTF GCN. We hereby, confirm ZTF20abbiixp as the afterglow of GRB 200524A.

We obtained the following photometric results:-

------------------------------------------------------------------

 JD(Start) | T-T0(hrs) | Filter | Mag |

------------------------------------------------------------------

2458994.174 | 11.11 | g | > 21.01

2458994.183 | 11.33 | r | 20.56 +/- 0.14

2458994.191 | 11.52 | i | 20.59 +/- 0.28

------------------------------------------------------------------

Given the fast fading of the source, we encourage the followup of the
source. The magnitudes are not corrected for galactic extinction.

The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree
field of view, set up by the Indian Institute of Astrophysics and the
Indian Institute of Technology Bombay with support from the Indo-US Science
and Technology Forum (IUSSTF) and the Science and Engineering Research
Board (SERB) of the Department of Science and Technology (DST), Government
of India (https://sites.google.com/view/growthindia/). It is located at the
Indian Astronomical Observatory (Hanle), operated by the Indian Institute
of Astrophysics (IIA).


GRB_name: GRB200524A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27805
SUBJECT: GRB 200524A: Liverpool Telescope observations
DATE:    20/05/24 22:28:15 GMT
FROM:    Daniel Perley at Liverpool JMU  <d.a.perley@ljmu.ac.uk>

D. A. Perley (LJMU) and Anna Ho (Caltech) report:

We observed the location of ZTF20abbiixp/AT2020krl (Ho et al., GCN 
27799), the presumed optical afterglow of GRB 200524A (Fana Dirirsa et 
al., GCN 27797), with the 2m robotic Liverpool Telescope between UT 
2020-05-24 21:39 and 21:53.  We acquired 120s of exposure time in each 
of the u, g, r, i, and z filters.  Photometry is as follows (all times 
relative to the LAT trigger as reported in GCN 27797):

  t_mid(d)  filter  magnitude
  --------  ------  ----------
  0.6921    z       20.49 +/- 0.15
  0.6941    i       20.86 +/- 0.09
  0.6961    r       21.03 +/- 0.07
  0.6981    g       21.32 +/- 0.06
  0.7000    u       21.64 +/- 0.24














DisclaimerNone


GRB_name: GRB200524A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27806
SUBJECT: GRB 200524A: 1.3m DFOT Optical Observation of ZTF20abbiixp
DATE:    20/05/24 22:32:48 GMT
FROM:    Amit Kumar at ARIES, India  <amitkundu515@gmail.com>

A. Kumar (ARIES), S. B. Pandey (ARIES), A. Ghosh (ARIES), Dimple (ARIES),
K. Misra (ARIES), R. Gupta (ARIES), K. Chand (ARIES) and A. Aryan (ARIES)
report:

We observed the optical afterglow of GRB 200524A (F. F. Dirirsa et al., GCN
27797, Evans et al., GCN 27798) with the 1.3m Devasthal Fast Optical
Telescope (DFOT) at Aryabhatta Research Institute of Observational Sciences
(ARIES), Nainital (India), from 2020-05-24T19:50:12 UTC (corresponding to
~14.770 hours after
the burst).

We observed 5 frames each of 300 seconds in Bessell I filter. In the
stacked image, we clearly detected the optical afterglow of GRB 200524A
(detected by Ho et al., GCN 27799, see also Kumar et al., GCN 27800,
Rumyantsev et al., GCN 27802 and Sanwal et al., GCN 27803).


The observed magnitude is as follows:

T_start-T0 (hours)   Start Date (UTC)    End Date (UTC)      Filter
   Magnitudes (mag)
---------------------------------------------------------------------------------------------------------------
14.770          2020-05-24T19:50:12     2020-05-24T20:32:37      I
      20.33 +- 0.07


Photometry is done based on the USNO-B1.0 catalog. The quoted magnitude is
not corrected for Galactic extinction.


GRB_name: GRB200524A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27807
SUBJECT: GRB 200524A: CAHA multicolor afterglow detection
DATE:    20/05/24 23:38:09 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), D. A. Kann, M. Blazek, 
C. Thoene, J. F. Agui Fernandez (all HETH/IAA-CSIC), R. Pedro Hedrosa, 
and A. Guijarro (both CAHA) report:

We observed the field of GRB 200524A (Fermi-LAT detection: Dirirsa et 
al. GCN #27797) with CAFOS, on the 2.2 m telescope, at Calar Alto 
observatory (Almeria, Spain). Observations consisted of 3 x 500 s in 
BVRc each, and 8 x 180 s in Ic-band.

The afterglow (Ho et al., GCN #27799, Kumar et al., GCN #27800, 
Rumyantsev et al., GCN #27802, Sanwal et al., GCN #27803, Perley et al., 
GCN #27805, Kumar et al., GCN #27806) is well-detected in each image. In 
an Rc image starting at 21:49:33 UT (mid-time 0.701188 days after the 
Fermi GBM trigger), we measure Rc = 20.86 +/- 0.12 mag (Vega mags) 
against five nearby SDSS stars transformed to the Rc band.


GRB_name: GRB200524A
Detection_method: Swift-UVOT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27808
SUBJECT: GRB 200524: Swift/UVOT observations missed the ZTF20abbiixp position
DATE:    20/05/24 23:43:57 GMT
FROM:    Paul Kuin at MSSL  <npkuin@gmail.com>

Paul Kuin (MSSL/UCL) and Kim Page (Leicester University)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200524
36366 s after the LAT trigger (Evans et al., GCN Circ. 27798).
The initial Swift UVOT follow up missed the likely afterglow of 200524A as
reported by Ho et al, GCN Circ. 27799, and confirmed by Kumar et al.
GCN Circ. 27800/27804/27806, Rumyantsev et al. GCN Circ. 27802,
Sanwal et al. GCN Circ. 27803, Perley et al., GCN Circ. 27805 and de
Ugarte Postigo et al, GCN.Circ. 27807. The UVOT field of view is smaller
than the XRT field of view and  XRT source 6 (Evans et al., GCN Circ.
 27798), which is consistent with the PTF source, falls outside the field
observed by Swift UVOT.


GRB_name: GRB200524A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27809
SUBJECT: GRB 200524A: Fermi GBM detection
DATE:    20/05/25 00:03:51 GMT
FROM:    Stephen Lesage at Fermi-GBM Team  <sjl0014@uah.edu>

S. Pookalil (UAH), B. Mailyan (Institute for Basic Science, South Korea),
and R. Hamburg (UAH)
report on behalf of the Fermi GBM Team:

"At 05:04:00.36 UT on 24 May 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 200524A (trigger 611989445 / GBM200524211),
which was also detected by the Fermi/LAT (Dirirsa et al. 2020, GCN 27797)
The Fermi GBM Final Real-time Localization is consistent with the LAT
position.
Swift has initiated a ToO observation of this burst (GCN 27798).

The angle from the Fermi LAT boresight at the GBM trigger time is 23
degrees.

The GBM light curve shows a multi-peaked structure
with a duration (T90) of about 38 s (50-300 keV).
The time-averaged spectrum from T0-1.5 s to T0+25.1 s is
best fit by a Band function with Epeak = 192 +/- 16 keV,
alpha = -0.66 +/- 0.06, and beta = -1.77 +/- 0.03

The event fluence (10-1000 keV) in this time interval is
(2.08 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+5.3 s in the 10-1000 keV band
is 13.3 +/- 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: GRB200524A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27810
SUBJECT: GRB 200524A: OAJ multicolor afterglow detection
DATE:    20/05/25 00:52:33 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

M. Blazek, D. A. Kann (both HETH/IAA-CSIC), A. de Ugarte Postigo 
(HETH/IAA-CSIC, DARK/NBI), C. Thoene, J. F. Agui Fernandez (both 
HETH/IAA-CSIC), and N. Maicas (CEFCA) report:

We observed the field of GRB 200524A (Fermi-LAT detection: Dirirsa et 
al. GCN #27797, Fermi GBM detection: Pookalil et al., GCN #27809) with 
the T80 0.8m telescope at the Observatorio de Javalambre (Teruel, 
Spain). Observations consisted of 3 x 300 s in g', 2 x 300 s in r', and 
5 x 180 s in i' and z' each.

The afterglow (Ho et al., GCN #27799, Kumar et al., GCN #27800, 
Rumyantsev et al., GCN #27802, Sanwal et al., GCN #27803, Perley et al., 
GCN #27805, Kumar et al., GCN #27806, de Ugarte Postigo et al., GCN 
#27807) is well-detected in each image. In the stacked r' image centered 
at 21:59:24 UT (mid-time 0.705135 days after the Fermi GBM trigger), we 
measure r' = 21.08 +/- 0.04 mag (AB mags) against PanSTARRS stars in the 
field.


GRB_name: GRB200524A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27811
SUBJECT: GRB 200524A: Swift-XRT afterglow detection
DATE:    20/05/25 04:14:56 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

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

Swift-XRT has performed follow-up observations of the
Fermi/LAT-detected burst GRB 200524A (Fana Dirirsa et al. GCN Circ.
27797), collecting 5.0 ks of Photon Counting (PC) mode data between
T0+36.4 ks and T0+55.7 ks. 

Four uncatalogued X-ray sources are detected, of which one ("Source 6")
is  believed to be the afterglow. Using 1644 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 = 213.04474, +60.90538 which is equivalent to:

RA (J2000): 14h 12m 10.74s
Dec(J2000): +60d 54' 19.4"

with an uncertainty of 4.4 arcsec (radius, 90% confidence). This
position is 9.2 arcmin from the Fermi/LAT position, and 3 arcsec from
ZTF20abbiixp (Ho et al., GCN 27799).

The light curve can be modelled with a power-law decay with a decay
index of alpha=3.42 (+0.06, -2.83).

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021001.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021001.

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


GRB_name: GRB171205A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27812
SUBJECT: GRB 171205A: ATCA observations of late-time radio emission
DATE:    20/05/25 04:50:43 GMT
FROM:    James Leung at U of Sydney/VAST  <jleu9465@uni.sydney.edu.au>

James Leung (University of Sydney/CSIRO), Tara Murphy (University of
Sydney), Emil Lenc (CSIRO), Dougal Dobie (University of Sydney/CSIRO),
David Kaplan (UWM)

We have performed two observations for GRB 171205A (V. Dâ€™Elia et al., GCN
Circ. 22177) centred on the optical afterglow position (L. Izzo et al.,
GCN Circ. 22180) with the Australia Telescope Compact Array (ATCA). The
observations took place on 2020 April 12 (859 days post-burst) and 2020
May 7 (884 days post-burst) at several frequencies. We report the
detections and 3-sigma limits below:

Date (UTC) | Freq (GHz) | Peak Flux Density (micro-Jy/beam)
-----------------------------------------------------------
2020/04/12 | 2.1        | 708 +/- 253
2020/04/12 | 5.5        | 412 +/- 47
2020/04/12 | 9.0        | 252 +/- 27
2020/04/12 | 16.7       | 112 +/- 38
2020/04/12 | 21.2       | < 87
2020/05/07 | 2.1        | 816 +/- 287
2020/05/07 | 5.5        | 440 +/- 52
2020/05/07 | 9.0        | 237 +/- 26
2020/05/07 | 16.7       | 133 +/- 50
2020/05/07 | 21.2       | < 122

We thank CSIRO staff for supporting these observations during these
especially difficult times.


GRB_name: GRB200524A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27813
SUBJECT: GRB 200524A: MITSuME Akeno optical observation
DATE:    20/05/25 07:18:07 GMT
FROM:    Ogawa Futa at Tokyo Institute of Technology  <ogawa@hp.phys.titech.ac.jp>

F. Ogawa, R. Hosokawa, R. Adachi, K. L. Murata, M. Niwano, N.
Nakamura, Y. Yatsu, and N. Kawai (TokyoTech) report on behalf of the
MITSuME collaboration:

We observed the field of GRB 200524A (Fermi-LAT detection: Dirirsa et
al., GCN #27797, Fermi-GBM detection: Pookalil et al., GCN #27809,
Swift-XRT afterglow detection: Capalbi et al. GCN #27811, and others)
with the optical three color (g', Rc, and Ic) CCD cameras attached to
the MITSuME 50 cm telescope of Akeno Observatory, Yamanashi, Japan.

The observation started on 13:07:01.89 UT. We detected a point source
clearly in g' and Rc band, and marginally in Ic band at the position
consistent with the afterglow reported previously (Ho et al., GCN
#27799, Kumar et al., GCN #27800, Rumyantsev et al., GCN #27802,
Sanwal et al., GCN #27803, Perley et al., GCN #27805, Kumar et al.,
GCN #27806, de Ugarte Postigo et al., GCN #27807, Blazek et al., GCN
#27810). We measured the magnitudes as follows.

T0+[hour] MID-UT T-EXP[sec] measured magnitudes
------------------------------------------------------------------------------------------------
8.03 13:10:54 420 g'=19.6+/-0.3, Rc=19.5+/-0.3, Ic=19.4+/-0.5
------------------------------------------------------------------------------------------------
T0+: Elapsed time after the burst
T-EXP: Total Exposure time

We used GSC2.3 catalog for flux calibration. The magnitudes are
expressed in the Vega system. The images were processed in real-time
through the MITSuME GPU reduction pipeline (Niwano et al. ,in prep;
https://github.com/MNiwano/Eclair)


GRB_name: GRB200524A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27814
SUBJECT: GRB 200524A: KAIT Optical Observations
DATE:    20/05/25 08:57:28 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, observed the field of GRB 200524A (Fermi-LAT
detection: Dirirsa et al., GCN 27797; Fermi GBM detection: Pookalil
et al., GCN 27809), starting at ~1.08 days after the burst.
We obtained 24x60s images in the clear (roughly R) filter. We detect
the optical afterglow at the location of ZTF20abbiixp/AT2020krl
(Ho et al., GCN 27799) in our co-added image. We estimate the afterglow,
which was also reported by other groups (Kumar et al., GCN 27800;
Rumyantsev et al., GCN 27802; Sanwal et al., GCN 27803; Perley et al.,
GCN 27805; Kumar et al., GCN 27806; de Ugarte Postigo et al., GCN
27807; Blazek et al., GCN 27810; Ogawa et al., GCN 27813), to be
21.2 +/- 0.2 magnitude in clear filter, calibrated to PS1 catalog.


GRB_name: GRB200521A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27815
SUBJECT: GRB200521A: ASIM observation
DATE:    20/05/25 09:18:56 GMT
FROM:    Martino Marisaldi at U of Bergen, Norway  <martino.marisaldi@uib.no>

M. Marisaldi (University of Bergen), A. Mezentsev (University of Bergen), 
N. Ã˜stgaard (University of Bergen), V. Reglero (University of Valencia) 
and T. Neubert (DTU Space) report on behalf of the ASIM Team:

At 12:16:39.798 UT on 21 May 2020, the Atmosphere-Space Interactions Monitor (ASIM)
mission triggered on the bright short hard GRB 200521A 
(AGILE detection: Verrecchia et al., GCN Circ. 27776;
CALET-GBM detection: Yoshida et al., GCN Circ. 27777;
CGBM-SPI-ACS triangulation: Sakamoto et al., GCN Circ. 27790;
IPN triangulation: Svinkin et al., GCN Circ. 27795;
Konus-Wind detection: Svinkin et al., GCN Circ. 27796)

Photon by photon data with <1 microsecond time resolution have been
collected for a time interval of two seconds centered at the trigger time.
As seen by the Modular X- and Gamma-Ray Sensor (MXGS) onboard ASIM
the burst consists of a single bright peak about 300 ms in duration. 
The emission is detected in the MXGS High Energy Detector (HED), 
sensitive in the range 0.3 to >30 MeV.  
Significant emission is observed up to several MeV. 
The MXGS Low Energy Detector (LED), sensitive in the range 0.05 to 0.4 MeV, 
was not active at trigger time.

ASIM is an ESA mission onboard the International Space Station dedicated to the 
observation of Terrestrial Gamma-ray Flashes (TGFs) and Transient Luminous Events (TLEs) 
operative since June 2018 (Neubert et al., Space Sci Rev (2019) 215:26 
https://doi.org/10.1007/s11214-019-0592-z <https://doi.org/10.1007/s11214-019-0592-z> ). 
The payload includes the Modular X- and Gamma-Ray Sensor (MXGS) 
(Ã˜stgaard et al., Space Sci Rev (2019) 215:23 https://doi.org/10.1007/s11214-018-0573-7 <https://doi.org/10.1007/s11214-018-0573-7> ), 
and the the Modular Multispectral Imaging Array  (MMIA) 
(Chanrion et al., Space Sci Rev (2019) 215:28 https://doi.org/10.1007/s11214-019-0593-y <https://doi.org/10.1007/s11214-019-0593-y> ). 
The ASIM Science Data Centre (ASDC) website is https://asdc.space.dtu.dk/ <https://asdc.space.dtu.dk/>


GRB_name: GRB200524A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27817
SUBJECT: GRB 200524A: Further Liverpool Telescope observations
DATE:    20/05/25 11:26:47 GMT
FROM:    Luca Izzo at DARK/NBI  <luca.izzo@gmail.com>

L. Izzo (DARK/NBI) reports:

We observed the field of GRB 200524A (Fermi-LAT detection: Dirirsa et al. GCN #27797, Fermi GBM detection: Pookalil et al., GCN #27809) with the IO:O camera mounted on the 2-m Liverpool Telescope located in La Palma, Spain. Observations started on May 25th at 01:08:27 UT (0.837 days after the GRB trigger) and we obtained a series of 5x60s images in the gri filters.

The afterglow (Ho et al., GCN #27799, Kumar et al., GCN #27800, Rumyantsev et al., GCN #27802, Sanwal et al., GCN #27803, Perley et al., GCN #27805, Kumar et al., GCN #27806, de Ugarte Postigo et al., GCN #27807, Blazek et al., GCN #27810, Ogawa et al., GCN #27813, Zheng et al., GCN #27814) is detected in all the stacked images. We measure a preliminary AB magnitude for the afterglow of g = 21.67 +- 0.35 mag (t_mid = 0.839 d), r = 21.37 +- 0.20 mag (t_mid = 0.844 d), i = 21.34 +- 0.25 mag(t_mid = 0.849 d) calibrated against Pan-STARRS catalogue stars.


GRB_name: GRB200524A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27818
SUBJECT: GRB 200524A: AstroSat CZTI detection
DATE:    20/05/25 14:44:59 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200524A, which was also detected by Fermi-LAT (Dirirsa F. et al., GCN #27797), Swift (Evans P.et al., GCN # 27798), ZTF (Ho A. et al., GCN # 27799), GROWTH-India (Kumar H. et al., GCN # 27800), Global MASTER-Net (Lipunov V. et al., GCN # 27801), CrAO (Rumyantsev V. et al., GCN # 27802), 3.6m DOT (Sanwal P. et al., GCN # 27803), Liverpool (Perley D. et al., GCN # 27805), CAHA (Postigo A. et al., GCN # 27807), Fermi GBM (Pookalil S. et al., GCN # 27809), OAJ (Blazek M. et al., GCN # 27810) and Swift-XRT (Capalbi M. et al., GCN # 27811).

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-05-24 05:04:05.494 UT. The measured peak count rate associated with the burst is 303 +/- 22 cts/s above the background in the combined data of four quadrants, with a total of 2111 +/- 37 cts. The local mean background count rate was 537 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 15.38 +/- 0.27 s.

It 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 2020-05-24 05:04:04.236 UT. The measured peak count rate is 430 +/- 40 cts/s above the background in the combined Veto data of four quadrants, with a total of 2951 +/- 79 cts. The local mean background count rate was 1623 +/- 3 cts/s.  We measure a T90 of 16.89 +/- 0.67 s from the cumulative Veto light curve.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200525A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27819
SUBJECT: GRB 200525A: Fermi GBM Final Real-time Localization
DATE:    20/05/25 14:50:33 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 14:40:28 UT on 25 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200525A (trigger 612110433.485766 / 200525611).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 20.6, Dec = -8.5 (J2000 degrees, equivalent to J2000 01h 22m, -8d 30'), with a statistical uncertainty of 5.7 degrees.

The angle from the Fermi LAT boresight is 65.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200525611/quicklook/glg_skymap_all_bn200525611.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200525611/quicklook/glg_healpix_all_bn200525611.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200525611/quicklook/glg_lc_medres34_bn200525611.gif


GRB_name: GRB200524A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27820
SUBJECT: GRB 200524A: Kitab observatory afterglow observations
DATE:    20/05/25 15:37:06 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), A. Novichonok (Petrozavodsk State University, KIAM), A. 
Pozanenko (IKI),  E. Mazaeva  (IKI), A. Volnova (IKI), I. Molotov 
(KIAM), Sh. Ehgamberdiev (UBAI) report on behalf of IKI-GRB-FuN:

We observed Fermi-LAT detected localization area of GRB 200524A (Dirirsa 
et al., GCN 27797; see also Pookalil et al., GCN 27809; Capalbi  et al., 
GCN 27811; Gupta et al., GCN 27818) with   Kitab-ISON RC-36  telescope 
starting on 2020-05-24 (UT) 19:07:41. In a stacked image in Clear filter 
(CR) we marginally detected optical afterglow discovered by ZTF (Ho et 
al., GCN 27799) and confirmed by several observations (Kumar et al. GCN 
27800; (Kumar et al., GCN 27800; Rumyantsev et al., GCN 27802; Sanwal et 
al., GCN 27803; Perley et al., GCN 27805; Kumar et al., GCN 27806; de 
Ugarte Postigo et al., GCN 27807; Blazek et al., GCN 27810; Ogawa et 
al., GCN 27813; Izzo, GCN 27817). Preliminary photometry is following

Date,      UT start, t-T0,   Exp., Filter,  OT,   Err., UL
                     (mid, days)
2020-05-24 19:07:41  0.60673 60*60 CR       20.48 0.25  21.0

The photometry is based on nearby USNO-B1.0 stars
USNO-B1.0_id R2
1508-0206198 15.78
1509-0204466 16.48
1509-0204434 16.53


GRB_name: GRB200524A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27821
SUBJECT: GRB 200524A: CrAO optical observations
DATE:    20/05/25 16:02:51 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), A. Pozanenko (IKI),  V. Rumyantsev (CrAO),  A. Volnova 
(IKI), E. Mazaeva (IKI) report on behalf of larger GRB follow-up 
collaboration:

We observed Fermi-LAT  GRB 200524A (Dirirsa et al., GCN 27797; see also 
Pookalil et al., GCN 27809; Capalbi  et al., GCN 27811; Gupta et al., 
GCN 27818) with ZTSH 2.6m telescope of CrAO observatory starting on 
2020-05-24 (UT) 19:35:16 (Rumyantsev et al., GCN 27802). Optical 
afterglow discovered by ZTF (Ho et al., GCN 27799) and confirmed by 
several observations (Kumar et al., GCN 27800; Rumyantsev et al., GCN 
27802; Sanwal et al., GCN 27803; Perley et al., GCN 27805; Kumar et al., 
GCN 27806; de Ugarte Postigo et al., GCN 27807; Blazek et al., GCN 
27810; Ogawa et al., GCN 27813; Izzo, GCN 27817). Preliminary photometry 
of the afterglow is following

Date,      UT start, t-T0,   Exp., Filter,  OT,   Err., UL
                     (mid, days)
2020-05-24 19:35:16  0.60644 240   R        20.43 0.05 22.6
2020-05-24 19:39:28  0.60935 240   R        20.48 0.05 22.7
2020-05-24 19:43:39  0.61226 240   R        20.52 0.05 22.7
2020-05-24 19:47:52  0.61519 240   R        20.55 0.05 22.6
2020-05-24 19:52:03  0.61809 240   R        20.60 0.08 22.5
2020-05-24 19:56:15  0.62101 240   R        20.59 0.09 22.5
2020-05-24 20:00:27  0.62392 240   R        20.60 0.09 22.3

The photometry is based on nearby USNO-B1.0 stars
USNO-B1.0_id R2
1508-0206198 15.78
1509-0204466 16.48
1509-0204434 16.53


GRB_name: GRB200522A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27822
SUBJECT: GRB 200522A: Gemini North optical imaging
DATE:    20/05/25 21:11:47 GMT
FROM:    Simone Dichiara at UMCP/NASA/GSFC  <dichiara@umd.edu>

S.Dichiara (UMD, NASA-GSFC), B. O'Connor (GWU, UMD) , E. Troja (UMD,
NASA-GSFC) report on behalf of a larger collaboration:

We observed the field of GRB 200522A (Evans et al., GCN Circ. 27778) with
the Gemini North telescope beginning 2020-05-24 14:36:32  UT, approximately
2.12 days post-burst. We obtained 7x90s exposures in r-band performed with
poor weather conditions and at an airmass of 2.9.

We measure an AB magnitude of r=21.37 +/- 0.10 for the putative host galaxy
(Fong et al., GCN Circ. 27779; Strausbaugh et al., GCN Circ. 27792).

No other object is detected within the enhanced Swift-XRT position
(Beardmore et al., GCN Circ. 27780) down to a 3-sigma limit r>22.3 AB.
Magnitudes are calibrated against the SDSS catalog and not corrected for
Galactic extinction.

Further observations are on-going.

A Chandra ToO has been approved for this burst.

We thank the Gemini North staff for efficiently executing these
observations in these difficult times.


GRB_name: GRB200525A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27823
SUBJECT: Fermi GRB 200525A: Global MASTER-Net observations report 
DATE:    20/05/26 04:45:14 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

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




MASTER-IAC robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 200525A ( Fermi GBM team, GCN 27819) errorbox  48792 sec after notice time and 48818 sec after trigger time at 2020-05-26 04:14:07 UT, with upper limit up to  17.7 mag. The observations began at zenith distance = 78 deg. The sun  altitude  is -22.1 deg. 

The galactic latitude b = -65 deg., longitude l = 123 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1365487

We obtain a following upper limits.  

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

   48849 | 2020-05-26 04:14:07 |          MASTER-IAC | (00h 26m 17.25s , -02d 04m 25.5s) |   C |    60 | 17.7 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200524A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27824
SUBJECT: GRB 200524A: optical upper limits from further MITSuME Akeno observation
DATE:    20/05/26 07:22:56 GMT
FROM:    Ryohei Hosokawa at Tokyo Institute of Technology  <hosokawa@hp.phys.titech.ac.jp>

R. Hosokawa, N. Nakamura, K. L. Murata, R. Adachi, M. Niwano, F.
Ogawa, Y. Yatsu, and N. Kawai (TokyoTech) report on behalf of the
MITSuME collaboration:

We performed further observation of the field of GRB 200524A
(Fermi-LAT detection: Dirirsa et al., GCN #27797, Fermi-GBM detection:
Pookalil et al., GCN #27809, Swift-XRT afterglow detection: Capalbi et
al. GCN #27811, and others) with the optical three color (g', Rc, and
Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno
Observatory, Yamanashi, Japan.

The observation started on 2020-05-25 11:27:25.65 UT. We did not
detect the optical afterglow (Ho et al., GCN #27799, Kumar et al., GCN
#27800, Rumyantsev et al., GCN #27802, Sanwal et al., GCN #27803,
Perley et al., GCN #27805, Kumar et al., GCN #27806, de Ugarte Postigo
et al., GCN #27807, Blazek et al., GCN #27810, Ogawa et al., GCN
#27813, Zheng et al., GCN #27814, Izzo et al., GCN #27817, Belkin et
al., GCN #27820, Belkin et al., GCN #27821) in the stacked images. We
obtained the 5-sigma limits as follows.

T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
30.5 2020-05-25 11:34:26 660 g'>18.7, Rc>18.7, Ic>18.0
------------------------------------------------------------------------------------------------
T0+: Elapsed time after the burst
T-EXP: Total Exposure time

We used the GSC2.3 catalog for flux calibration. The magnitudes are
expressed in the Vega system. The images were processed in real-time
through the MITSuME GPU reduction pipeline (Niwano et al. ,in prep;
https://github.com/MNiwano/Eclair)


GRB_name: GRB200524A
Detection_method: correction
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27825
SUBJECT: GRB200524A: UVOT detection
DATE:    20/05/26 13:49:24 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

Swift UVOT did a further follow up of the Fermi-LAT detected GRB200524A
(Dirirsa et al. GCN Circ. 27797). We detect the afterglow discovered
by Ho et al. (GCN Circ. 27799), ZTF20abbiixp, in the UVOT white filter
in 5.4ks exposure taken between To+1.15d and To+1.57d, with
 white = 22.06 +/- 0.12 magnitudes (on the UVOT photometric system,
Breeveld et al. 2011, AIP Conf. Proc. 1358, 373 ).  The source
does not vary significantly during these observations.
No correction has been made for the Galactic reddening E(B-V)=0.02
(Schlafy et al., ApJ 737, 10, 2011)


GRB_name: GRB200522A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27826
SUBJECT: GRB 200522A: Hubble Space Telescope Near-IR F160W Observations
DATE:    20/05/26 14:43:47 GMT
FROM:    Wen-fai Fong at Northwestern U  <wfong@northwestern.edu>

W. Fong (Northwestern), E. Berger (Harvard), J. Rastinejad (Northwestern) and C. D. Kilpatrick (UCSC) report on behalf of a larger collaboration:

"We initiated Hubble Space Telescope (HST) observations of the field of GRB 200522A (Evans et al., GCN 27778; Beardmore et al., GCN 27780) under Program 15964 (PI: Berger). We obtained WFC3/IR imaging in the F160W band, at a mid-time on 2020 May 26.077 UT (3.6 days post-burst). A total of 5223-sec of exposure time was obtained.

Coincident with the XRT position (90% confidence), we detect two clearly extended sources, Sources A and B. We perform absolute astrometry with SDSS DR12 and use WFC3 tabulated zeropoints to determine the following:

Source A:
RA(J2000) = 00:22:43.72
Dec(J2000) = -00:16:57.46
m(F160W) = 20.7 AB mag

Source B:
RA(J2000) = 00:22:43.82
Dec(J2000) = -00:16:59.54
m(F160W) = 23.7 AB mag.

Source A is the catalogued SDSS galaxy (Fong et al., GCN 27786) and exhibits a disturbed morphology, while Source B is considerably fainter. The angular offsets from the XRT positional center are ~2.0" and ~2.1", and the light of both galaxies are ~50% encompassed by the XRT position (90% confidence). Using NIR number counts, we estimate Pchance ~ 0.01 and 0.11 for Sources A and B, respectively.

We do not detect any additional sources, point-like or extended, within the XRT position or at the position of the additional LCO optical source (Strausbaugh et al., GCN 27794) to a 3-sigma limiting magnitude of m(F160W)>27.2 mag.

Assuming an optical decline rate of F~t^-1 from the time of the LCO faint source detection (R~22.57; Strausbaugh et al., GCNs 27792, 27794) to 3.6 days, and typical afterglow colors, the expected afterglow magnitude is m(F160W)~23.6 mag, which is >3 mag brighter than the HST limit. If we assume that a jet break occurred at t~1 day, this still results in expected afterglow magnitudes of ~25.5 mag, >1 mag brighter than the HST limit. We thus conclude that either the LCO source is not real, or that the afterglow exhibited a very steep decline of t^-3.5 or steeper beyond ~1 day.

At the redshift of the putative host galaxy of z~0.4 (Fong et al., GCN 27786), F160W roughly corresponds to rest-frame J-band. Scaling the J-band kilonova light curve of GW170817 (Villar et al. 2017: ApJL, 851, L21) to z~0.4, we find that the HST limit is slightly deeper than the kilonova of GW170817 at the same time.

The results of WFC3/F125W observations, which have been taken but are not yet available, will be discussed in an upcoming circular. We thank the HST staff for quickly implementing these observations."


GRB_name: GRB200522A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27827
SUBJECT: GRB 200522A: HST F125W new point source detection
DATE:    20/05/26 16:30:44 GMT
FROM:    Wen-fai Fong at Northwestern U  <wfong@northwestern.edu>

W. Fong (Northwestern), C. D. Kilpatrick (UCSC), J. Rastinejad (Northwestern) and E. Berger (Harvard) report on behalf of a larger collaboration:

"We report on further HST/WFC3 observations of GRB200522A (Evans et al., GCN 27778) taken under Program 15964 in the F125W filter. A total of 5223-sec of exposure time was obtained roughly at the same mid-time of ~3.6 days. We detect sources A and B (Fong et al., GCN 27826), as well as an additional point-like source C at:

RA(J2000) = 00:22:43.62
Dec(J2000) = -00:16:57.56

This position is ~1.2" away from the center of the LCO faint source position (Strausbaugh et al., GCN 27794), ~1.5" offset from Source A, and at the edge of the XRT position (90% confidence). While there is some contamination from the host galaxy that introduces uncertainty, we estimate a magnitude for Source C of m(F125W)~26.8 +/- 0.3 AB mag. Regarding the LCO source, the positional offset, coupled with the fact that Source C is considerably fainter than extrapolations based on afterglow evolution, suggests that the potential LCO source and Source C are not related.

The color of Source C is blue, with F125W-F160W < -0.4 mag. This color is more consistent with those of afterglows (-0.3 mag) than the corresponding redder color of the kilonova of GW170817 (~0.2-0.4 mag; comparing to rest-frame z-J assuming z~0.4). However, further observations are necessary to determine the nature of this source, assess its variability, and its relation to GRB 200522A."


GRB_name: GRB200524A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27830
SUBJECT: GRB 200524A: Assy optical observations
DATE:    20/05/27 15:13:26 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), V. Kim (AFIF, Pulkovo Observatory), A. Pozanenko (IKI), 
M. Krugov (AFIF),  E. Mazaeva  (IKI),  A. Volnova (IKI)  report on 
behalf of larger GRB IKI FuN collaboration:

We observed Fermi-LAT  GRB 200524A (Dirirsa et al., GCN 27797; see also 
Pookalil et al., GCN 27809; Capalbi  et al., GCN 27811; Gupta et al., 
GCN 27818) with AZT-20 1.5 m telescope  of Assy-Turgen observatory 
starting on May. 26 (UT) 15:34:49  in  r'-filter. Optical afterglow 
discovered by ZTF (Ho et al., GCN 27799) and observed by several 
observations (Kumar et al., GCN 27800; Rumyantsev et al., GCN 27802; 
Sanwal et al., GCN 27803; Perley et al., GCN 27805; Kumar et al., GCN 
27806; de Ugarte Postigo et al., GCN 27807; Blazek et al., GCN 27810; 
Ogawa et al., GCN 27813; Izzo, GCN 27817; Belkin et al., GCN 27820; Kuin 
et al., GCN 27825). Preliminary photometry of the afterglow is following

Photometry of the field is following.

Date       UT start   t-T0       Filter Exp.   OT   Err.   UL (3sigma)
                       (mid, days)        (s)

2020-05-26 15:34:49   2.4721     r'(AB) 98*60  22.57 0.10  24.4

The photometry is based on the nearby stars of PS1 catalog.
PanSTARRS-PS1_id   r
181072130294808209 20.4066
181072130171186332 20.9877
181082129951473104 20.1196


GRB_name: GRB200528A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27831
SUBJECT: GRB 200528A: Fermi GBM Final Real-time Localization
DATE:    20/05/28 10:37:56 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 10:27:24 UT on 28 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200528A (trigger 612354449.346938 / 200528436).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 169.2, Dec = 60.2 (J2000 degrees, equivalent to J2000 11h 16m, 60d 12'), with a statistical uncertainty of 1.0 degrees.

The angle from the Fermi LAT boresight is 19.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200528436/quicklook/glg_skymap_all_bn200528436.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200528436/quicklook/glg_healpix_all_bn200528436.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200528436/quicklook/glg_lc_medres34_bn200528436.gif


GRB_name: GRB200528A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27832
SUBJECT: GRB 200528A: Swift detection of a burst
DATE:    20/05/28 10:39:36 GMT
FROM:    Kim Page at U.of Leicester  <klp5@leicester.ac.uk>

E. Ambrosi (INAF-IASFPA), V. D'Elia (SSDC), P. A. Evans (U Leicester),
J.D. Gropp (PSU), N. J. Klingler (PSU), H. A. Krimm (NSF),
F. E. Marshall (NASA/GSFC) and K. L. Page (U Leicester) report on
behalf of the Neil Gehrels Swift Observatory Team:

At 10:27:23 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200528A (trigger=974827).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 176.637, +58.147 which is 
   RA(J2000) = 11h 46m 33s
   Dec(J2000) = +58d 08' 50"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a multi-peaked
structure with a duration of about 60 sec.  The peak count rate
was ~19000 counts/sec (15-350 keV), at ~33 sec after the trigger. 

The XRT began observing the field at 10:28:33.9 UT, 70.2 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 176.6438, 58.1921 which is equivalent to:
   RA(J2000)  = 11h 46m 34.51s
   Dec(J2000) = +58d 11' 31.6"
with an uncertainty of 5.2 arcseconds (radius, 90% containment). This
location is 162 arcseconds from the BAT onboard position, within the
BAT error circle. No event data are yet available to determine the
column density using X-ray spectroscopy. 

The initial flux in the 0.1 s image was 4.08e-08 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 80 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
0.01. 

Burst Advocate for this burst is E. Ambrosi (elena.ambrosi 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: GRB200528A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27833
SUBJECT: GRB 200528A: Potential host galaxy in PanSTARRS, SDSS and WISE
DATE:    20/05/28 11:19:38 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

A. de Ugarte Postigo (HETH/IAA-CSIC, DARK/NBI), and D. A. Kann 
(HETH/IAA-CSIC) report:

Within the XRT error circle of GRB 200528A (Fermi GBM team, GCN #27831; 
Ambrosi et al., GCN #27832), a bright, extended object is detected, at 
position (J2000, from SDSS):

RA = 176.64297
Dec. = 58.19313

It is found to have (from SDSS):

u' = 22.28 +/-0.42 mag;
g' = 21.46 +/- 0.075 mag;
r' = 20.45 +/- 0.047 mag;
i' = 20.13 +/- 0.052 mag;
z' = 19.88 +/- 0.147 mag.

It is also detected in PanSTARRS and WISE with W1 = 16.7 +/- 0.1 mag.

The photometric redshift in SDSS is given as z = 0.380 +/- 0.0792.

We suggest this galaxy to be the host galaxy of GRB 200528A. The early 
non-detection in UVOT indicates this might be an optically dark GRB, as 
the X-ray light curve is very bright early on. The X-ray column density 
is unknown so far (Ambrosi et al., GCN #27832) but likely to be high.

Confirmation or rejection awaits a refined XRT position once data are 
obtainable in PC mode.


GRB_name: GRB200528A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27834
SUBJECT: GRB 200528A: MITSuME Akeno optical upper limits
DATE:    20/05/28 13:14:26 GMT
FROM:    Adachi Ryo at Tokyo Institute of Tech  <adachi@hp.phys.titech.ac.jp>

R. Adachi, R. Hosokawa, K. L. Murata, M. Niwano, F. Ogawa, N.
Nakamura, Y. Yatsu, and N. Kawai (Tokyo Tech) report on behalf of the
MITSuME collaboration:

We observed the field of GRB 200528A (Fermi GBM team, GCN #27831;
Ambrosi et al., GCN #27832) with the optical three color (g', Rc, and
Ic) CCD cameras attached to the MITSuME 50 cm telescopes of Akeno
Observatory in Japan.

The observation started on 10:28:31.87 UT. The first 40 images were
heavily affected by twilight and bad weather at Akeno Observatory. We
checked single images and combined images. We did not find any new
point sources within the Swift/XRT error circle (Ambrosi et al., GCN
#27832) in all three bands. Also, we did not detect the potential host
galaxy (de Ugarte Postigo et al., GCN #27833) due to shallow upper
limits of our observation. We obtained the 5-sigma limits as follows.

T0+[min] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
36.7 11:28:34 1020 g'>18.9, Rc>18.3, Ic>17.4
------------------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time

We used the UCAC4 catalog for flux calibration. The magnitudes are
expressed in the AB system. The images were processed in real-time
through the MITSuME GPU reduction pipeline (Niwano et al., submitted;
https://github.com/MNiwano/Eclair).


GRB_name: GRB200528A
Detection_method: Swift Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27835
SUBJECT: Swift GRB 200528A: Global MASTER-Net observations report 
DATE:    20/05/28 13:24:40 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

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




MASTER-Amur robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Blagoveshchensk State Pedagogical University) was pointed to the Swift GRB 200528A ( E. Ambrosi et al., GCN 27832) errorbox  9786 sec after notice time and 9804 sec after trigger time at 2020-05-28 13:10:47 UT, with upper limit up to  16.7 mag. Observations started at twilight.  The observations began at zenith distance = 22 deg. The sun  altitude  is -12.3 deg. 

The galactic latitude b = 57 deg., longitude l = 138 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1368165

We obtain a following upper limits.  

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

    9894 |         MASTER-Amur |   C |   180 | 16.7 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200528A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27836
SUBJECT: GRB 200528A: Enhanced Swift-XRT position
DATE:    20/05/28 14:43:12 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 910 s of XRT Photon Counting mode data and 3 UVOT
images for GRB 200528A, 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 = 176.63744, +58.19257 which is equivalent
to:

RA (J2000): 11h 46m 32.99s
Dec (J2000): +58d 11' 33.3"

with an uncertainty of 1.8 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: GRB200528A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27837
SUBJECT: GRB 200528A: Nanshan/NEXT optical upper limit
DATE:    20/05/28 16:59:24 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

Z.P. Zhu, S.Y. Fu, X. Liu, D. Xu (NAOC), X. Gao (Urumqi No.1 Senior High 
School), X. Zhang, J.Z. Liu (XAO) report:

We observed the field of GRB 2005528A (Ambrosi et al., GCN 27832) using 
the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 
5x120s frames in the Sloan r-band, starting at 15:55:41 UT on 
2020-05-28, i.e., 5.47 hr after the burst.

No optical source is detected in our stacked image at the enhanced XRT 
position (Evans et al., GCN 27836), down to a limiting magnitude of 
r~20.1, calibrated with nearby SDSS field.


GRB_name: GRB200528A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27838
SUBJECT: GRB 200528A: 1.3m DFOT Optical Upper Limits
DATE:    20/05/28 17:52:58 GMT
FROM:    Amit Kumar at ARIES, India  <amitkundu515@gmail.com>

A. Kumar (ARIES), S. B. Pandey (ARIES), R. Gupta (ARIES), K. Misra (ARIES),
A. Aryan (ARIES), A. Ghosh (ARIES), and Dimple (ARIES) report:

We carried out observation of Fermi GBM detected GRB 200528A (GCN 27831,
Ambrosi et al., GCN 27832) with the 1.3m Devasthal Fast Optical Telescope
(DFOT) at Devasthal observatory of Aryabhatta Research Institute of
observational sciencES (ARIES), India.

The observation was started on 2020-05-28T15:37:05 UTC. We observed a
series of 4 x 300s exposures using the Bessell I filter covering Swift XRT
enhanced position (Evans et al., 27836).

We do not detect any new optical source within the Swift XRT enhanced error
circle in individual as well as in the stacked image (Adachi et al., GCN
27834, Lipunov et al., GCN 27835 and Zhu et al., GCN 27837).

We obtained the 3-sigma upper limit as follows:

T_start-T0(hrs) Start Date (UTC)  End Date (UTC)   Filter  Limit (mag)
-----------------------------------------------------------------------------------------------
5.161    2020-05-28T15:37:05  2020-05-28T15:58:42   I     20.2 +- 0.2



Photometry is done based on the USNO-B1.0 catalog. This magnitude is not
corrected for Galactic extinction in the direction of the GRB.


GRB_name: GRB200528A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27839
SUBJECT: GRB 200528A: Swift-BAT refined analysis
DATE:    20/05/28 21:45:22 GMT
FROM:    Hans Krimm at NSF/NASA-GSFC  <hkrimm@nsf.gov>

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

Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 200528A (trigger #974827)
(Ambrosi, et al., GCN Circ. 27832).  The BAT ground-calculated position is
RA, Dec = 176.637, 58.185 deg which is 
  RA(J2000)  =  11h 46m 32.8s 
  Dec(J2000) = +58d 11' 07.3" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 62%.

The mask-weighted light curve shows a multi-peaked structure rising just before T0,
peaking around T+35 sec and decaying to background by T+120 sec.
T90 (15-350 keV) is 58.7 +- 1.4 sec (estimated error including systematics).

The time-averaged spectrum from T-1.02 to T+112.88 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.62 +- 0.14, 
and Epeak of 40.1 +- 5.5 keV (chi squared 25.28 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 1.8 +- 0.0 x 10^-5 erg/cm2
and the 1-sec peak flux measured from T+33.82 sec in the 15-150 keV band is
17.5 +- 0.5 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 2.14 +- 0.03 (chi squared 69.65 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/974827/BA/


GRB_name: GRB200528A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27840
SUBJECT: GRB 200528A: Swift/UVOT Upper Limits
DATE:    20/05/28 22:25:58 GMT
FROM:    Frank Marshall at Swift/UVOT  <marshall@milkyway.gsfc.nasa.gov>

F. E. Marshall (NASA/GSFC) and E. Ambrosi (INAF-IASFPA)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200528A
81 s after the BAT trigger (Ambrosi et al., GCN Circ. 27832).
No optical afterglow consistent with the enhanced XRT position
(Evans et al. GCN Circ. 27836) 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            81          231          147         >21.1
u                  293          305           12         >18.7
v                 5743         5942          197         >18.8
b                 5127         5327          169         >20.7
uvw2              5538         5738          197         >21.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200528A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27841
SUBJECT: GRB 200528A: Fermi GBM Observation
DATE:    20/05/28 23:28:45 GMT
FROM:    Cori Fletcher at USRA  <cfletcher@usra.edu>

C. Fletcher (USRA), A. von Kienlin and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 10:27:24.35 UT on 28 May 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 200528A (trigger 612354449 / 200528436)
which was also detected by the Swift/BAT (Ambrosi et al. 2020, GCN 27832)
The Fermi GBM Final Real-time Localization (GCN 27831) is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 16 degrees.

The GBM light curve shows multiple peaks
with a duration (T90) of about 56 s (50-300 keV).
The time-averaged spectrum from T0+2.05 s to T0+59.4 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.39 +/- 0.02 and
the cutoff energy, parameterized as Epeak, is 55.5 +/- 0.8 keV.

The event fluence (10-1000 keV) in this time interval is
(2.54 +/- 0.02)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+33.3 s in the 10-1000 keV band
is 27.2 +/- 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: GRB200528A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27842
SUBJECT: GRB 200528A: NOT optical upper limits
DATE:    20/05/29 00:02:50 GMT
FROM:    Daniele B Malesani at DTU Space  <malesani@space.dtu.dk>

D. B. Malesani (DTU Space), J. P. U. Fynbo (DAWN/NBI), L. Izzo 
(DARK/NBI), D. Xu (NAOC/CAS), T. Pursimo (NOT), report on behalf of a 
larger collaboration:

We observed the field of GRB 200528A (Ambrosi et al., GCN 27832) using 
the Nordic Optical Telescope (NOT) equipped with the ALFOSC camera. 
Observations were carried out under variable, thin clouds. After 
stacking the good images in each filter, no afterglow is visible in 
either band within the XRT position (Evans et al., GCN 27836). At mean 
epochs May 28.926 and 28.927 UT (11.78 and 11.80 hr after the GRB, 
respectively), we derive limiting magnitudes r > 23.5 and z > 22 AB 
(calibrated against nearby stars in the Pan-STARRS catalog).

We note that the galaxy visible in the archival surveys and noted by de 
Ugarte Postigo & Kann (GCN 27833) is about 10.6 arcsec away of the 
UVOT-enhanced XRT position (1.5" error; Evans et al., GCN 27836), and is 
thus likely unrelated to the GRB.


GRB_name: GRB200529A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27844
SUBJECT: GRB 200529A: Fermi GBM Final Real-time Localization
DATE:    20/05/29 01:06:53 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 00:56:39 UT on 29 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200529A (trigger 612406604.278114 / 200529039).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 239.2, Dec = -18.1 (J2000 degrees, equivalent to J2000 15h 56m, -18d 06'), with a statistical uncertainty of 8.5 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/2020/bn200529039/quicklook/glg_skymap_all_bn200529039.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200529039/quicklook/glg_healpix_all_bn200529039.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200529039/quicklook/glg_lc_medres34_bn200529039.gif


GRB_name: GRB200529A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27845
SUBJECT: GRB 200529A: Swift detection of a burst
DATE:    20/05/29 01:13:29 GMT
FROM:    Amy Lien at GSFC  <amy.y.lien@nasa.gov>

V. D'Elia (SSDC), E. Ambrosi (INAF-IASFPA), A. D'Ai (INAF-IASFPA),
J.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU),
H. A. Krimm (NSF), S. Laha (GSFC/UMBC/CRESST), A. Y. Lien (GSFC/UMBC),
F. E. Marshall (NASA/GSFC), M. J. Moss (GWU), D. M. Palmer (LANL),
A. Tohuvavohu (U Toronto) and T. N. Ukwatta (LANL) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 00:56:35 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200529A (trigger=974942).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 238.751, -11.057 which is 
   RA(J2000) = 15h 55m 00s
   Dec(J2000) = -11d 03' 25"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a weak pulse
with a duration of about 30 sec.  The peak count rate
was ~1700 counts/sec (15-350 keV), at ~1 sec after the trigger. 

The XRT began observing the field at 01:00:08.7 UT, 212.9 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 238.76571, -11.07215 which is
equivalent to:
   RA(J2000)  = 15h 55m 03.77s
   Dec(J2000) = -11d 04' 19.7"
with an uncertainty of 5.2 arcseconds (radius, 90% containment). This
location is 75 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. 

UVOT took a finding chart exposure of 144 seconds with the White filter
starting 216 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 56% 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
0.29. 

Burst Advocate for this burst is V. D'Elia (delia AT ssdc.asi.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: GRB200529A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27846
SUBJECT: GRB 200529A: NOT optical afterglow
DATE:    20/05/29 01:39:44 GMT
FROM:    Daniele B Malesani at DTU Space  <malesani@space.dtu.dk>

Daniele B. Malesani (DTU Space), Tapio Pursimo (NOT), Charles L. 
Steinhardt (DAWN/NBI), report:

We observed the field of GRB 200529A (D'Elia et al., GCN 27845) using 
the Nordic Optical Telescope equipped with the ALFOSC camera.

In a single 300-s image, starting on May 29.052 UT (18.9 min after the 
GRB), we detect a bright point source just outside the currently 
available XRT position, which is not visible in the archival Pan-STARRS 
images of the same field. We measure for this object the following 
position (J2000):

RA = 15:55:03.21
Dec = -11:04:26.2

By comparison with nearby stars from the Pan-STARRS catalog, we measure 
a magnitude r = 20.00 +- 0.02.

We conclude that this object is the optical afterglow of GRB 200529A.


GRB_name: GRB200529A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27847
SUBJECT: GRB 200529A: KAIT Optical Afterglow Confirmation
DATE:    20/05/29 06:56:59 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, observed the field of GRB 200529A (GBM detection:
GCN 27844; Swift detection: D'Elia et al., GCN 27845), starting at
~5.25 hours after the burst. We obtained 23x60s images in the clear
(roughly R) filter. We marginally detect, therefore confirm the
optical afterglow reported by Malesani et al. (GCN 27846) in our
co-added image. We estimate the afterglow to be 21.2 +/- 0.2 magnitude
in clear filter, calibrated to PS1 catalog.


GRB_name: GRB200529A
Detection_method: Swift-XRT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27848
SUBJECT: GRB 200529A: Enhanced Swift-XRT position
DATE:    20/05/29 06:59:54 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.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 1535 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 200529A, 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 = 238.76394, -11.07363 which is equivalent
to:

RA (J2000): 15h 55m 3.34s
Dec (J2000): -11d 04' 25.1"

with an uncertainty of 1.8 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: GRB200528A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27849
SUBJECT: GRB 200528A: Assy optical upper limit
DATE:    20/05/29 08:09:05 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), V. Kim (AFIF, Pulkovo Observatory), A. Pozanenko (IKI), 
M. Krugov (AFIF),  E. Mazaeva  (IKI),  A. Volnova (IKI)  report on 
behalf of larger GRB IKI FuN collaboration:

We observed  GRB 200528A (Fermi GBM Team  GCN 27831;   Ambrosi  et al., 
GCN 27832) with AZT-20 1.5 m telescope  of Assy-Turgen observatory 
starting on May., 28 (UT) 16:16:12.
We do not detect any sources in the Swift-XRT extended position (Evans 
et al., GCN 27836).

Preliminary photometry of the field is following.

Date       UT start   t-T0       Filter Exp.   OT   Err.   UL (3sigma)
                       (mid, days)        (s)

2020-05-28 16:16:12   0.26777    r(AB)  54*60  n/d  n/d    22.4

The photometry is based on the nearby stars of SDSS catalog

SDSS-DR12_id        r
J114613.33+581329.5 19.455
J114632.90+581307.2 19.190
J114549.81+581044.3 19.004
J114600.53+580839.6 16.985


GRB_name: GRB200524A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27850
SUBJECT: GRB 200524A: Assy continued optical observations
DATE:    20/05/29 08:45:32 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), V. Kim (AFIF, Pulkovo Observatory), A. Pozanenko (IKI),
M. Krugov (AFIF),  E. Mazaeva  (IKI),  A. Volnova (IKI)  report on
behalf of larger GRB IKI FuN collaboration:

We observed   GRB 200524A (Dirirsa et al., GCN 27797; Pookalil et al., 
GCN 27809; Capalbi  et al., GCN 27811; Gupta et al., GCN 27818) with 
AZT-20 1.5 m telescope  of Assy-Turgen observatory starting on May. 27 
(UT) 17:29:53  in  r'-filter. Optical afterglow discovered by ZTF (Ho et 
al., GCN 27799) and observed by several observations (Kumar et al., GCN 
27800; Rumyantsev et al., GCN 27802; Sanwal et al., GCN 27803; Perley et 
al., GCN 27805; Kumar et al., GCN 27806; de Ugarte Postigo et al., GCN 
27807; Blazek et al., GCN 27810; Ogawa et al., GCN 27813; Izzo, GCN 
27817; Belkin et al., GCN 27820; Kuin et al., GCN 27825).
Preliminary photometry of the afterglow is following

Date       UT start   t-T0      Filter  Exp.    OT    Err.   UL (3sigma)
                        (mid, days)      (s)

2020-05-27 17:29:53   3.55617   r'(AB)  110*60  22.80  0.17  24.4

The photometry is based on the nearby stars of PS1 catalog.


GRB_name: GRB200524A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27851
SUBJECT: GRB 200524A: SAO RAS optical observations
DATE:    20/05/29 09:29:23 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), A. Moskvitin (SAO RAS), A. Pozanenko (IKI), E. Mazaeva 
(IKI),  A. Volnova (IKI)  report on behalf of larger GRB IKI FuN 
collaboration:

We observed   GRB 200524A (Dirirsa et al., GCN 27797; Pookalil et al., 
GCN 27809; Capalbi  et al., GCN 27811; Gupta et al., GCN 27818) with 
Zeiss-1.0 m telescope  of SAO RAS observatory  in  Rc-filter. Optical 
afterglow discovered by ZTF (Ho et al., GCN 27799) and observed by 
several observations (Kumar et al., GCN 27800; Rumyantsev et al., GCN 
27802; Sanwal et al., GCN 27803; Perley et al., GCN 27805; Kumar et al., 
GCN 27806; de Ugarte Postigo et al., GCN 27807; Blazek et al., GCN 
27810; Ogawa et al., GCN 27813; Izzo, GCN 27817; Belkin et al., GCN 
27820; Kuin et al., GCN 27825).

Preliminary photometry is following

Date       UT start   t-T0      Filter  Exp.   OT    Err.   UL (3sigma)
                        (mid, days)      (s)

2020-05-27 21:48:28   3.71143   Rc      2400   22.54  0.20  23.6
2020-05-28 22:17:40   4.73171   Rc      2400   n/d    n/d   22.6

The photometry is based on the nearby stars of SDSS DR12 catalog and 
Lupton' transformation gri -> R.


GRB_name: GRB200528A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27852
SUBJECT: GRB 200528A: Swift-XRT refined Analysis
DATE:    20/05/29 10:39:04 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

M. Perri (ASDC), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), B. Sbarufatti
(PSU), D.N. Burrows (PSU), J. D. Gropp (PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester) and
E. Ambrosi report on behalf of the Swift-XRT team:

We have analysed 5.7 ks of XRT data for GRB 200528A (Ambrosi et al. GCN
Circ. 27832), from 73 s to 50.9 ks after the  BAT trigger. The data
comprise 226 s in Windowed Timing (WT) mode with the remainder in
Photon Counting (PC) mode. The enhanced XRT position for this burst was
given by Evans et al. (GCN Circ. 27836).

The late-time light curve (from T0+5.1 ks) can be modelled with a
power-law decay with a decay index of alpha=0.97 (+/-0.07).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.30 (+/-0.05). The
best-fitting absorption column is  3.63 (+0.19, -0.18) x 10^21 cm^-2,
in excess of the Galactic value of 1.2 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.24 (+0.16, -0.15)
and a best-fitting absorption column of 3.8 (+0.7, -0.6) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.4 x 10^-11 (6.1 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:      3.8 (+0.7, -0.6) x 10^21 cm^-2
Galactic foreground: 1.2 x 10^20 cm^-2
Excess significance: 9.8 sigma
Photon index:      2.24 (+0.16, -0.15)

If the light curve continues to decay with a power-law decay index of
0.97, the count rate at T+24 hours will be 0.041 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.4 x
10^-12 (2.5 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/00974827.

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


GRB_name: GRB200529A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27853
SUBJECT: GRB 200529A: BOOTES-2/TELMA early optical upper limit
DATE:    20/05/29 10:54:37 GMT
FROM:    Youdong HU at IAA-CSIC  <youdong@iaa.es>

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC), C. Perez 
del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga), R. 
Fernandez-Munoz (IHSM/UMA-CSIC), M.D. Caballero-Garcia and M. Jelinek 
(ASU-CAS), on behalf of a larger collaboration, report:

The 60cm BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) 
in Algarrobo Costa (Malaga, Spain) automatically responded to GRB 
200529A as detected by Swift (D'Elia et al GCNC 27845). No new source is 
seen in the initial 10s exposure gathered at 00:58:28 UT(~ 113 s after 
the burst onset) down to a 18.0 limiting magnitude. Further images (20 x 
10s) were combined to produce a deeper image down to 18.8 mag limit at 
median time of 10.5 min post burst. No early-time bright optical 
emission is detected at the NOT (Malesani et al. GCNC 27846) and KAIT 
(Zheng et al. GCNC 27847) reported optical afterglow.

We thank the staff at La Mayora for its excellent support.


GRB_name: GRB200529B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27854
SUBJECT: GRB 200529B: Fermi GBM Final Real-time Localization
DATE:    20/05/29 12:15:53 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 12:05:34 UT on 29 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200529B (trigger 612446739.895772 / 200529504).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 337.2, Dec = 55.2 (J2000 degrees, equivalent to J2000 22h 28m, 55d 12'), with a statistical uncertainty of 3.6 degrees.

The angle from the Fermi LAT boresight is 35.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200529504/quicklook/glg_skymap_all_bn200529504.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200529504/quicklook/glg_healpix_all_bn200529504.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200529504/quicklook/glg_lc_medres34_bn200529504.gif


GRB_name: GRB200528A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27855
SUBJECT: GRB 200528A: CALET Gamma-Ray Burst Monitor detection
DATE:    20/05/29 12:29:14 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

V. Pal'shin, A. Yoshida, T. Sakamoto, S. Sugita (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (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 soft GRB 200528A (Swift detection: Ambrosi et al.,
GCN Circ. 27832, Barthelmy et al., GCN Circ. 27839;
Fermi GBM observation: Fletcher and Meegan, GCN Circ. 27841;
https://gcn.gsfc.nasa.gov/other/200528A.gcn3)
triggered the CALET Gamma-ray Burst Monitor (CGBM) at 10:27:27.087 UTC
on 28 May 2020. The burst signal was seen by all CGBM detectors.
Because of a problem in one of the ground alert processing script,
the GCN notice was not distributed automatically for this event.

The burst light curve shows a multi-peaked structure which starts at
T-4.5 sec, peaks at T+30.8 sec and ends at T+35.1 sec. The T90 and T50
durations measured by the SGM data are 36.6 +- 3.2 sec and 27.9 +- 4.0 sec
(40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1274696855/

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


GRB_name: GRB200529B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27857
SUBJECT: Fermi GRB 200529B: Global MASTER-Net observations report 
DATE:    20/05/29 13:15:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

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




MASTER-Amur robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Blagoveshchensk State Pedagogical University) started inspect of the Fermi GRB 200529B ( Fermi GBM team, GCN 27854) errorbox  2976 sec after notice time and 3002 sec after trigger time at 2020-05-29 12:55:37 UT, with upper limit up to  14.8 mag. Observations started at twilight.  The observations began at zenith distance = 65 deg. The sun  altitude  is -10.7 deg. 

The galactic latitude b = -7 deg., longitude l = 104 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1368860

We obtain a following upper limits.  

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

    3032 | 2020-05-29 12:55:37 |         MASTER-Amur | (22h 18m 14.11s , +56d 00m 18.3s) |   C |    60 | 12.9 |        
    3112 | 2020-05-29 12:56:56 |         MASTER-Amur | (22h 34m 45.33s , +53d 59m 24.8s) |   C |    60 | 12.7 |        
    3191 | 2020-05-29 12:58:15 |         MASTER-Amur | (22h 07m 32.10s , +53d 59m 30.6s) |   C |    60 | 12.8 |        
    3271 | 2020-05-29 12:59:35 |         MASTER-Amur | (22h 25m 19.03s , +52d 00m 14.2s) |   C |    60 | 12.4 |        
    3350 | 2020-05-29 13:00:55 |         MASTER-Amur | (22h 18m 08.85s , +56d 01m 11.0s) |   C |    60 | 13.8 |        
    3431 | 2020-05-29 13:02:15 |         MASTER-Amur | (22h 32m 32.38s , +56d 00m 04.3s) |   C |    60 | 14.8 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200529A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27858
SUBJECT: GRB 200529A: LCO Optical Afterglow Detection
DATE:    20/05/29 13:24:48 GMT
FROM:    Robert Strausbaugh at U. of the Virgin Islands  <robert.strausbaugh@uvi.edu>

R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (U. of the Virgin Islands/College of Marin) report on behalf of a larger collaboration:

We observed Swift GRB 200529A (D'Elia et al., GCN 27845) with the LCO 1-m Sinistro instrument at the Siding Spring Observatory, Australia site, on May 29, from 10:05 to 10:28 UT (corresponding to 9.15 to 9.53 hours from the GRB trigger time) with the Bessel R and I filters.

We performed a series of 5x120s exposures in R and I. We clearly detect an optical source in R band, and force a detection in I band with less than one sigma significance, in stacked images at a location consistent with other optical afterglow detections (Malesani et al., GCN 27846; Zheng et al., GCN 27847).  Using the USNO-B.1 catalog as reference, we calculate the following magnitudes:

R = 21.76 +/- 0.18

I = 22.82 +/- 1.06

These magnitudes are not corrected for galactic extinction.

R.S. is funded by NSF AST grant #1831682


GRB_name: GRB200529A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27859
SUBJECT: GRB 200529A: Fermi GBM Detection
DATE:    20/05/29 16:50:37 GMT
FROM:    Oliver J Roberts at USRA/NASA  <oliver.roberts@nasa.gov>

O.J. Roberts (USRA) and C. Meegan (UAH) report on behalf of
the Fermi GBM Team:

"At 00:56:39.28 UT on May 29th 2020, the Fermi 
Gamma-Ray Burst Monitor (GBM) triggered and located 
GRB 200529A (trigger 612406604 / 200529039) which was 
also detected by the Swift (V. D'Elia et al. 2020, GCN 27845). 
The Fermi GBM Final Real-time Localization (GCN 27844) 
is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time 
is 77 degrees.

The GBM light curve shows multiple peaks with a duration 
(T90) of about 85 s (50-300 keV). The time-averaged spectrum 
from T0-3.5 s to T0+81.5 s is best fit by a power law function 
with an exponential high-energy cutoff. 
The power law index is -1.34 (+0.16/-0.15) and the cutoff 
energy, parameterized as Epeak, is 73.99 (+11.10/-8.18) keV.

The event fluence (10-1000 keV) in this time interval is
(4.08 +/- 0.27)E-06 erg/cm^2. The 1-sec peak photon flux 
Measured starting from T0+17.8 s in the 10-1000 keV band
is 2.7 +/- 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: GRB200528A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27860
SUBJECT: GRB 200528A: CAHA Upper Limit
DATE:    20/05/29 22:44:01 GMT
FROM:    Alexander Kann at IAA-CSIC  <kann@iaa.es>

D. A. Kann (HETH/IAA-CSIC), A. de Ugarte Postigo (HETH/IAA-CSIC, 
DARK/NBI), M. Blazek, C. C. Thoene, J. F. Agui Fernandez (all 
HETH/IAA-CSIC), and I. Hermelo (CAHA) report:

We observed the XRT error circle (Evans et al., GCN #27836) of the 
bright GRB 200528A (Swift detection: Ambrosi et al., GCN #27832; Fermi 
GBM detection: The Fermi GBM team, GCN #27831) with the 2.2m telescope 
at CAHA (Almeria, Spain), equipped with the CAFOS detector. We obtained 
21 x 180 s exposures in the Ic band under adverse observing conditions 
(moonlight, bad seeing and transparency).

At the enhanced XRT position, we detect no source (but would have 
preferred to). We derive a 3 sigma limiting magnitude of Ic > 23.5 mag 
(Vega) at 0.440865 days after the GRB, calibrated against SDSS standard 
stars transformed to the Ic band following Lupton (2005). This limit is 
comparable to those achieved by NOT about an hour later (Malesani et 
al., GCN #27842).


GRB_name: GRB200530A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27861
SUBJECT: GRB 200530A: Fermi GBM Final Real-time Localization
DATE:    20/05/30 00:54:31 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 00:44:10 UT on 30 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200530A (trigger 612492255.567684 / 200530031).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 17.3, Dec = 71.9 (J2000 degrees, equivalent to J2000 01h 09m, 71d 54'), with a statistical uncertainty of 2.5 degrees.

The angle from the Fermi LAT boresight is 37.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200530031/quicklook/glg_skymap_all_bn200530031.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200530031/quicklook/glg_healpix_all_bn200530031.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200530031/quicklook/glg_lc_medres34_bn200530031.gif


GRB_name: GRB200530A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27862
SUBJECT: Fermi GRB 200530A: Global MASTER-Net observations report 
DATE:    20/05/30 01:00:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

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




MASTER-IAC robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 200530A ( Fermi GBM team, GCN 27861) errorbox  592 sec after notice time and 619 sec after trigger time at 2020-05-30 00:54:29 UT, with upper limit up to  16.1 mag. The observations began at zenith distance = 75 deg. The sun  altitude  is -40.2 deg. 

The galactic latitude b =  9 deg., longitude l = 125 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1369228

We obtain a following upper limits.  

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

     679 | 2020-05-30 00:54:29 |          MASTER-IAC | (01h 06m 24.58s , +71d 45m 48.9s) |  P| |   120 | 16.1 |        


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


GRB_name: GRB200529A
Detection_method: Swift-XRT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27863
SUBJECT: GRB 200529A: Swift-XRT refined Analysis
DATE:    20/05/30 01:13:03 GMT
FROM:    Phil Evans at U of Leicester  <pae9@leicester.ac.uk>

A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU), J. D. Gropp (PSU), J.A.
Kennea (PSU), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester),
P.A. Evans (U. Leicester), A. Melandri (INAF-OAB) and V. D'Elia report
on behalf of the Swift-XRT team:

We have analysed 3.7 ks of XRT data for GRB 200529A (D'Elia et al. GCN
Circ. 27845), from 197 s to 44.3 ks after the  BAT trigger. The data
comprise 51 s in Windowed Timing (WT) mode (the first 8 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Goad et al.
(GCN Circ. 27848).

The light curve can be modelled with an initial power-law decay with an
index of alpha=4.0 (+/-0.6), followed by a break at T+580 s to an alpha
of 0.44 (+0.19, -0.17).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.29 (+0.29, -0.20). The
best-fitting absorption column is  consistent with the Galactic value
of 2.4 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 2.8 x 10^-11 (4.5 x 10^-11) erg cm^-2 count^-1. 

A summary of the WT-mode spectrum is thus:
Total column:      2.4 (+/-0.8) x 10^21 cm^-2
Galactic foreground: 2.4 x 10^21 cm^-2
Excess significance: <1.6 sigma
Photon index:      2.29 (+0.29, -0.20)

If the light curve continues to decay with a power-law decay index of
0.44, the count rate at T+24 hours will be 0.013 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.7 x
10^-13 (5.9 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/00974942.

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


GRB_name: GRB200530A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27864
SUBJECT: GRB 200530A: AstroSat CZTI detection
DATE:    20/05/30 11:18:25 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200530A, which was also detected by Fermi GBM (GCN #27861) and Global MASTER-Net (Lipunov V. et al., GCN # 27862).

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-05-30 00:44:20.150 UT. The measured peak count rate associated with the burst is 669 +/- 29 cts/s above the background in the combined data of four quadrants, with a total of 8172 +/- 74 cts. The local mean background count rate was 498 +/- 2 cts/s. Using cumulative rates, we measure a T90 of 20.98 +/- 0.08 s. In preliminary analysis, we find that 605 Compton events are associated with this event.

It 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 2020-05-30 00:44:19.000 UT. The measured peak count rate is 709 +/- 46 cts/s above the background in the combined Veto data of four quadrants, with a total of 5449 +/- 134 cts. The local mean background count rate was 1431 +/- 3 cts/s.  We measure a T90 of 20.87 +/- 0.31 s from the cumulative Veto light curve.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200524A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27867
SUBJECT: Konus-Wind observation of GRB 200524A
DATE:    20/05/30 14:10:03 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

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

The long-duration GRB 200524A
(Fermi-LAT detection: Fana Dirirsa et al., GCN Circ. 27797;
Fermi-GBM detection: Pookalil et al., GCN Circ. 27809;
AstroSat-CZTI detection: Gupta et al., GCN Circ. 27818)
triggered Konus-Wind at T0=18243.246 s UT (05:04:03.246).

The burst light curve shows a multipeaked structure
which starts at ~T0-4.8 s, peaks at ~T0-3.3 s,
and to background level at ~T0+84 s.
The total burst duration is ~89 s.
The emission is seen up to ~10 MeV.

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200524_T18243/

As observed by Konus-Wind, the burst
had a fluence of 3.48(-0.62,+0.74)x10^-5 erg/cm2,
and a 64-ms peak flux, measured from T0+3.280 s,
of 6.33(-1.64,+1.75)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-averaged spectrum of the burst
(measured from T0 to T0+40.704 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.75(-0.18,+0.25),
the high energy photon index beta = -2.13(-0.31,+0.20),
the peak energy Ep = 215(-46,+48) keV
(chi2 = 105/97 dof).

The spectrum near the maximum count rate
(measured from T0+0.256 to T0+7.936 s)
is best fit in the 20 keV - 10 MeV range
by the GRB (Band) model with the following parameters:
the low-energy photon index alpha = -0.55(-0.18,+0.26),
the high energy photon index beta = -2.14(-0.21,+0.16),
the peak energy Ep = 203(-36,+36) keV
(chi2 = 130/97 dof).

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB200529A
Detection_method: Swift-BAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27868
SUBJECT: GRB 200529A: Swift-BAT refined analysis
DATE:    20/05/30 14:22:59 GMT
FROM:    Sibasish Laha at GSFC  <sibasish.laha@nasa.gov>

H. A. Krimm (NSF), S. D. Barthelmy (GSFC),
J. R. Cummings (CPI), V. D'Elia (SSDC),
S. Laha (GSFC/UMBC), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL)
(i.e. the Swift-BAT team):

Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 200529A (trigger #974942)
(V. D'Elia, et al., GCN Circ. 27845).  The BAT ground-calculated position is
RA, Dec = 238.756, -11.076 deg which is
   RA(J2000)  =  15h 55m 01.3s
   Dec(J2000) = -11d 04' 34.5"
with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 50%.

The mask weighted light curve shows a complex structure. The
overall structure starts at ~T-5 s and lasts till ~T+100 s.
T90 (15-350 keV) is 79.57 +- 7.26 sec (estimated error including systematics).

The time-averaged spectrum from T-1.24 to T+92.92 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.89 +- 0.10.  The fluence in the 15-150 keV band is 3.2 +- 0.2 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+1.58 sec in the 15-150 keV band
is 1.8 +- 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/974942/BA/


GRB_name: GRB200531A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27870
SUBJECT: GRB 200531A: Fermi GBM Final Real-time Localization
DATE:    20/05/31 03:01:39 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 02:51:18 UT on 31 May 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200531A (trigger 612586283.524172 / 200531119).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 164.6, Dec = 31.9 (J2000 degrees, equivalent to J2000 10h 58m, 31d 53'), with a statistical uncertainty of 8.1 degrees.

The angle from the Fermi LAT boresight is 124.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200531119/quicklook/glg_skymap_all_bn200531119.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200531119/quicklook/glg_healpix_all_bn200531119.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200531119/quicklook/glg_lc_medres34_bn200531119.gif


GRB_name: GRB200531A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27874
SUBJECT: Fermi GRB 200531A: Global MASTER-Net observations report 
DATE:    20/05/31 18:00:34 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200531A ( Fermi GBM team, GCN 27870) errorbox  52660 sec after notice time and 52687 sec after trigger time at 2020-05-31 17:29:26 UT, with upper limit up to  18.7 mag. The observations began at zenith distance = 69 deg. The sun  altitude  is -22.2 deg. 

The galactic latitude b = 66 deg., longitude l = 196 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1369918

We obtain a following upper limits.  

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

   52718 | 2020-05-31 17:29:26 |         MASTER-SAAO | (10h 46m 11.37s , +36d 08m 43.4s) |   C |    60 | 18.7 |        
   52718 | 2020-05-31 17:29:26 |         MASTER-SAAO | (10h 45m 11.52s , +36d 07m 55.3s) |   C |    60 | 18.6 |        
   52798 | 2020-05-31 17:30:46 |         MASTER-SAAO | (10h 56m 10.98s , +36d 07m 51.0s) |   C |    60 | 18.7 |        
   52798 | 2020-05-31 17:30:46 |         MASTER-SAAO | (10h 55m 11.16s , +36d 07m 03.0s) |   C |    60 | 18.6 |        
   52877 | 2020-05-31 17:32:05 |         MASTER-SAAO | (11h 13m 35.60s , +38d 07m 06.9s) |   C |    60 | 18.5 |        
   52877 | 2020-05-31 17:32:06 |         MASTER-SAAO | (11h 12m 34.34s , +38d 06m 19.5s) |   C |    60 | 18.6 |        
   52957 | 2020-05-31 17:33:25 |         MASTER-SAAO | (11h 11m 12.09s , +40d 07m 43.2s) |   C |    60 | 18.3 |        
   52957 | 2020-05-31 17:33:25 |         MASTER-SAAO | (11h 02m 13.47s , +40d 06m 17.2s) |   C |    60 | 18.6 |        
   53245 | 2020-05-31 17:38:13 |         MASTER-SAAO | (10h 56m 05.86s , +36d 06m 51.1s) |   C |    60 | 18.4 |        
   53245 | 2020-05-31 17:38:13 |         MASTER-SAAO | (10h 55m 07.12s , +36d 06m 10.8s) |   C |    60 | 18.6 |        
   53325 | 2020-05-31 17:39:33 |         MASTER-SAAO | (11h 11m 12.29s , +40d 08m 48.9s) |   C |    60 | 18.0 |        
   53325 | 2020-05-31 17:39:33 |         MASTER-SAAO | (11h 02m 13.42s , +40d 07m 25.0s) |   C |    60 | 18.4 |        
   53405 | 2020-05-31 17:40:53 |         MASTER-SAAO | (11h 23m 02.23s , +40d 07m 03.9s) |   C |    60 | 18.3 |        
   53485 | 2020-05-31 17:42:13 |         MASTER-SAAO | (10h 35m 25.66s , +36d 09m 00.6s) |   C |    60 | 18.3 |        
   53485 | 2020-05-31 17:42:13 |         MASTER-SAAO | (10h 26m 55.17s , +36d 07m 35.4s) |   C |    60 | 18.6 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200601A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27876
SUBJECT: GRB 200601A: Fermi GBM Final Real-time Localization
DATE:    20/06/01 02:30:08 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 02:19:49 UT on 1 Jun 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200601A (trigger 612670794.995442 / 200601097).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 36.7, Dec = 33.5 (J2000 degrees, equivalent to J2000 02h 26m, 33d 30'), with a statistical uncertainty of 1.7 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/2020/bn200601097/quicklook/glg_skymap_all_bn200601097.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200601097/quicklook/glg_healpix_all_bn200601097.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200601097/quicklook/glg_lc_medres34_bn200601097.gif


GRB_name: GRB200601A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27877
SUBJECT: Fermi GRB 200601A: Global MASTER-Net observations report 
DATE:    20/06/01 05:15:07 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

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




MASTER-IAC robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 200601A ( Fermi GBM team, GCN 27876) errorbox  8734 sec after notice time and 8763 sec after trigger time at 2020-06-01 04:45:53 UT, with upper limit up to  17.6 mag. Observations started at twilight.  The observations began at zenith distance = 72 deg. The sun  altitude  is -16.1 deg. 

The galactic latitude b = -26 deg., longitude l = 122 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1370430

We obtain a following upper limits.  

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

    8794 | 2020-06-01 04:45:53 |          MASTER-IAC | (02h 08m 25.01s , +33d 54m 13.3s) |   C |    60 | 17.5 |        
    8794 | 2020-06-01 04:45:53 |          MASTER-IAC | (02h 18m 15.55s , +33d 49m 56.3s) |   C |    60 | 16.7 |        
    8919 | 2020-06-01 04:47:58 |          MASTER-IAC | (02h 11m 40.38s , +35d 55m 25.3s) |   C |    60 | 17.5 |        
    8919 | 2020-06-01 04:47:58 |          MASTER-IAC | (02h 21m 45.69s , +35d 51m 10.0s) |   C |    60 | 17.0 |        
    9037 | 2020-06-01 04:49:57 |          MASTER-IAC | (02h 05m 27.38s , +31d 54m 52.6s) |   C |    60 | 17.6 |        
    9038 | 2020-06-01 04:49:57 |          MASTER-IAC | (02h 15m 04.89s , +31d 50m 35.2s) |   C |    60 | 16.8 |        
    9398 | 2020-06-01 04:55:58 |          MASTER-IAC | (02h 08m 21.31s , +33d 53m 58.1s) |   C |    60 | 17.3 |        
    9398 | 2020-06-01 04:55:58 |          MASTER-IAC | (02h 18m 11.77s , +33d 49m 43.5s) |   C |    60 | 16.7 |        
    9517 | 2020-06-01 04:57:56 |          MASTER-IAC | (02h 11m 40.42s , +35d 54m 00.0s) |   C |    60 | 17.2 |        
    9517 | 2020-06-01 04:57:56 |          MASTER-IAC | (02h 21m 45.36s , +35d 49m 46.7s) |   C |    60 | 16.7 |        
    9637 | 2020-06-01 04:59:56 |          MASTER-IAC | (02h 15m 07.94s , +31d 51m 13.5s) |   C |    60 | 16.5 |        
    9763 | 2020-06-01 05:02:03 |          MASTER-IAC | (02h 21m 20.94s , +29d 54m 07.3s) |   C |    60 | 16.7 |        
    9763 | 2020-06-01 05:02:03 |          MASTER-IAC | (02h 30m 46.39s , +29d 49m 46.6s) |   C |    60 | 14.5 |        
    9879 | 2020-06-01 05:03:59 |          MASTER-IAC | (02h 15m 12.84s , +37d 55m 29.6s) |   C |    60 | 16.6 |        
    9879 | 2020-06-01 05:03:59 |          MASTER-IAC | (02h 25m 33.63s , +37d 51m 16.9s) |   C |    60 | 16.0 |        
    9997 | 2020-06-01 05:05:56 |          MASTER-IAC | (02h 02m 50.92s , +29d 54m 53.3s) |   C |    60 | 16.8 |        
    9997 | 2020-06-01 05:05:56 |          MASTER-IAC | (02h 12m 15.86s , +29d 50m 37.2s) |   C |    60 | 16.0 |        
   10116 | 2020-06-01 05:07:56 |          MASTER-IAC | (02h 21m 17.05s , +29d 56m 07.0s) |   C |    60 | 16.2 |        
   10116 | 2020-06-01 05:07:56 |          MASTER-IAC | (02h 30m 42.39s , +29d 51m 47.8s) |   C |    60 | 15.5 |        
   10247 | 2020-06-01 05:10:06 |          MASTER-IAC | (02h 15m 13.90s , +37d 54m 53.3s) |   C |    60 | 16.3 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200529A
Detection_method: MITSuME
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27878
SUBJECT: GRB 200529A: MITSuME Akeno optical upper limits
DATE:    20/06/01 06:45:39 GMT
FROM:    Ogawa Futa at Tokyo Institute of Technology  <ogawa@hp.phys.titech.ac.jp>

F. Ogawa, R. Adachi, R. Hosokawa, M. Niwano, K. L. Murata, N.
Nakamura, Y. Yatsu, and N. Kawai(TokyoTech) report on behalf of the
MITSuME collaboration:

We observed the field of GRB 200529A (Fermi GBM team, GCN #27844;
D'Elia et al. GCN #27845) with the optical three color (g', Rc, and
Ic) CCD cameras attached to the MITSuME 50 cm telescope of Akeno
Observatory, Yamanashi, Japan.

The observation started on 10:25:35 UT. The first 47 images were
heavily affected by the bad weather at Akeno Observatory. We did not
detect the optical afterglow (Daniele et al., GCN #27846; WeiKang et
al., GCN #27847; Strausbaugh et al., GCN #27858) in the stacked image.
We obtained the 5-sigma limits as follows.

T0+[hour] MID-UT T-EXP[sec] 5-sigma limits
------------------------------------------------------------------------------------------------
10.3 11:35:06 1140 g'>17.3, Rc>17.1, Ic>16.5
------------------------------------------------------------------------------------------------
T0+: Elapsed time after the burst
T-EXP: Total Exposure time

We used UCAC4 catalog for flux calibration. The magnitudes are
expressed in the AB system. The images were processed in real-time
through the MITSuME GPU reduction pipeline (Niwano et al., submitted;
https://github.com/MNiwano/Eclair)


GRB_name: GRB200601A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27882
SUBJECT: GRB 200601A: Insight-HXMT/HE detection
DATE:    20/06/02 07:59:21 GMT
FROM:    YaoGuang Zheng at IHEP  <zhengyg@ihep.ac.cn>

Y. G. Zheng, C. Cai, Y. F. Du, W. C. Xue, 
Q. Luo, S. Xiao, Q. B. Yi, C. K. Li, G. Li, 
X. B. Li, J. Y. Liao, S. L. Xiong,C. Z. Liu, 
X. F. Li, Z. W. Li, Z. Chang, A. M. Zhang, Y. F. Zhang, 
X. F. Lu, C. L. Zou (IHEP), Y. J. Jin, Z. Zhang (THU), 
T. P. Li (IHEP/THU), F. J. Lu, L. M. Song, 
M. Wu, Y. P. Xu, S. N. Zhang (IHEP), 
report on behalf of the Insight-HXMT team:

At 2020-06-01T02:19:56.50 (T0), Insight-HXMT/HE detected 
GRB 200601A (trigger ID: HEB200601097) in a routine search of the data, 
which also triggered Fermi/GBM (GCN #27876).

The Insight-HXMT/HE light curve mainly consists of multiple 
pulses with a duration (T90) of 149.42 s measured from T0-2.12 s. 
The 1-ms peak rate, measured from T0-1.08 s, is 808 cnts/sec. 
The total counts from this burst is 29488 counts. 
URL_LC: http://twiki.ihep.ac.cn/pub/HXMT/GRBList/HEB200601097_lc.jpg

All measurements above are made with the CsI detectors operating in the 
regular mode with the energy range of about 80-800 keV (deposited energy). 
Only gamma-rays with energy greater than about 200 keV can penetrate 
the spacecraft and leave signals in the CsI detectors installed inside 
of the telescope. 

Insight-HXMT is the first Chinese space X-ray telescope, which was 
funded jointly by the China National Space Administration (CNSA) and 
the Chinese Academy of Sciences (CAS). 
More information about it could be found at: 
http://www.hxmt.org.


GRB_name: GRB200528A
Detection_method: Konus-Wind Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27883
SUBJECT: Konus-Wind observation of GRB200528A
DATE:    20/06/02 09:06:41 GMT
FROM:    Anastasia Tsvetkova at Ioffe Institute  <tsvetkova@mail.ioffe.ru>

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

The long-duration, soft-spectrum GRB200528A
(Swift detection: Ambrosi et al., GCN 27832;
Barthelmy et al., GCN 27839;
Fermi GBM Observation: Fletcher, von Kienlin & Meegan, GCN 27841;
CALET Gamma-Ray Burst Monitor detection: Pal'shin et al., GCN 27855)
triggered Konus-Wind at T0=37675.256 s UT (10:27:55.256).

The burst light curve shows a complex structure
which starts at ~T0-33.8 s, with a total duration of~60.0 s,
and comprises two double-peaked emission episodes.
The emission is seen up to ~1 MeV.

As observed by Konus-Wind, the burst
had a fluence of 2.12(-0.07,+0.07)x10^-5 erg/cm2,
and a 64-ms peak energy flux, measured from T0+1.696 s,
of 2.38(-0.35,+0.35)x10^-6 erg/cm2/s
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum of the burst
(measured from T0 to T0+33.024 s)
is best fit in the 20 keV - 1 MeV range
by a power law with exponential cutoff model:
dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep)
with  alpha = -1.41(-0.14,+0.14),
and Ep = 64(-5,+5) keV (chi2 = 50/60 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -2.89 (chi2 = 49/59 dof).

The spectrum near the peak count rate
(measured from T0+0.256 to T0+8.448 s)
is best fit in the 20 keV - 1 MeV range
by the power law with exponential cutoff model
with  alpha = -1.14(-0.15,+0.16),
and Ep = 75(-4,+5) keV (chi2 = 52/60 dof).
Fitting by the GRB (Band) model yields the same alpha and Ep,
and an upper limit on the high energy photon index:
beta < -3.03 (chi2 = 51/59 dof).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB200528_T37675/

All the quoted errors are at the 90% confidence level.
All the quoted values are preliminary.


GRB_name: GRB200529A
Detection_method: Swift-UVOT Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27884
SUBJECT: GRB 200529A: Swift/UVOT Upper Limits
DATE:    20/06/03 01:43:27 GMT
FROM:    Kira Simpson at PSU  <kira.simpson1984@gmail.com>

GRB 200529A: Swift/UVOT Upper Limits

K. K. Simpson (PSU) and V. D'Elia (SSDC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 200529A
195 s after the BAT trigger (D'Elia et al., GCN Circ. 27845).
No optical afterglow consistent with the optical position
(Malesani et al. GCN Circ. 27846)
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           216          360          142         >19.8
white              216          360          142         >19.8
v                  195         3771          209         >19.1
b                 4392         4495          102         >19.5
u                 4187         4386          197         >19.7
w1                3982         4182          197         >19.0
m2                3777         3977          197         >20.2

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.29 in the direction of the burst
(Schlegel et al. 1998).


GRB_name: GRB200604A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27887
SUBJECT: GRB 200604A: Fermi GBM Final Real-time Localization
DATE:    20/06/04 20:10:21 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 LONG GRB

At 20:00:05 UT on 4 Jun 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200604A (trigger 612993610.010234 / 200604833).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 179.5, Dec = -3.9 (J2000 degrees, equivalent to J2000 11h 58m, -3d 53'), with a statistical uncertainty of 10.1 degrees.

The angle from the Fermi LAT boresight is 54.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200604833/quicklook/glg_skymap_all_bn200604833.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200604833/quicklook/glg_healpix_all_bn200604833.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200604833/quicklook/glg_lc_medres34_bn200604833.gif


GRB_name: GRB200604A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27888
SUBJECT: Fermi GRB 200604A: Global MASTER-Net observations report 
DATE:    20/06/04 21:30:27 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200604A ( Fermi GBM team, GCN 27887) errorbox  405 sec after notice time and 432 sec after trigger time at 2020-06-04 20:07:17 UT, with upper limit up to  18.5 mag. The observations began at zenith distance = 45 deg. The sun  altitude  is -55.5 deg. 

MASTER-Kislovodsk robotic telescope  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 200604A errorbox  2698 sec after notice time and 2725 sec after trigger time at 2020-06-04 20:45:30 UT, with upper limit up to  17.0 mag. The observations began at zenith distance = 77 deg. The sun  altitude  is -24.2 deg. 

MASTER-IAC robotic telescope  located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 200604A errorbox  4925 sec after notice time and 4951 sec after trigger time at 2020-06-04 21:22:36 UT, with upper limit up to  17.8 mag. Observations started at twilight.  The observations began at zenith distance = 43 deg. The sun  altitude  is -17.0 deg. 

The galactic latitude b = 56 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=1374035

We obtain a following upper limits.  

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

     462 | 2020-06-04 20:07:17 |         MASTER-SAAO | (11h 36m 25.90s , -07d 50m 28.6s) |   C |    60 | 18.3 |        
     462 | 2020-06-04 20:07:17 |         MASTER-SAAO | (11h 29m 26.39s , -07d 51m 49.2s) |   C |    60 | 18.2 |        
     542 | 2020-06-04 20:08:37 |         MASTER-SAAO | (11h 30m 06.23s , -01d 50m 59.3s) |   C |    60 | 18.1 |        
     542 | 2020-06-04 20:08:37 |         MASTER-SAAO | (11h 23m 10.86s , -01d 52m 21.0s) |   C |    60 | 18.4 |        
     622 | 2020-06-04 20:09:57 |         MASTER-SAAO | (11h 40m 19.11s , -09d 52m 33.2s) |   C |    60 | 18.5 |        
     622 | 2020-06-04 20:09:57 |         MASTER-SAAO | (11h 33m 17.34s , -09d 53m 52.8s) |   C |    60 | 18.4 |        
     702 | 2020-06-04 20:11:16 |         MASTER-SAAO | (11h 17m 24.75s , -05d 52m 31.3s) |   C |    60 | 18.3 |        
     702 | 2020-06-04 20:11:16 |         MASTER-SAAO | (11h 10m 27.36s , -05d 53m 52.6s) |   C |    60 | 18.4 |        
    1981 | 2020-06-04 20:32:35 |         MASTER-SAAO | (11h 36m 24.88s , -07d 52m 49.0s) |   C |    60 | 18.1 |        
    1981 | 2020-06-04 20:32:35 |         MASTER-SAAO | (11h 29m 25.59s , -07d 54m 09.2s) |   C |    60 | 17.9 |        
    2060 | 2020-06-04 20:33:55 |         MASTER-SAAO | (11h 30m 05.02s , -01d 52m 10.2s) |   C |    60 | 17.6 |        
    2060 | 2020-06-04 20:33:55 |         MASTER-SAAO | (11h 23m 09.90s , -01d 53m 31.1s) |   C |    60 | 17.7 |        
    2140 | 2020-06-04 20:35:15 |         MASTER-SAAO | (11h 40m 20.68s , -09d 51m 17.8s) |   C |    60 | 18.0 |        
    2140 | 2020-06-04 20:35:15 |         MASTER-SAAO | (11h 33m 19.22s , -09d 52m 36.8s) |   C |    60 | 18.0 |        
    2220 | 2020-06-04 20:36:34 |         MASTER-SAAO | (11h 17m 22.87s , -05d 52m 53.0s) |   C |    60 | 17.0 |        
    2220 | 2020-06-04 20:36:34 |         MASTER-SAAO | (11h 10m 25.83s , -05d 54m 13.3s) |   C |    60 | 17.0 |        
    2300 | 2020-06-04 20:37:54 |         MASTER-SAAO | (11h 20m 22.06s , -07d 51m 39.8s) |   C |    60 | 17.0 |        
    2300 | 2020-06-04 20:37:54 |         MASTER-SAAO | (11h 13m 23.24s , -07d 52m 59.3s) |   C |    60 | 17.0 |        
    2380 | 2020-06-04 20:39:14 |         MASTER-SAAO | (11h 29m 33.39s , +00d 08m 32.3s) |   C |    60 | 16.6 |        
    2380 | 2020-06-04 20:39:14 |         MASTER-SAAO | (11h 22m 38.75s , +00d 07m 12.2s) |   C |    60 | 16.8 |        
    2460 | 2020-06-04 20:40:34 |         MASTER-SAAO | (11h 15m 15.25s , -03d 51m 11.9s) |   C |    60 | 16.5 |        
    2539 | 2020-06-04 20:41:54 |         MASTER-SAAO | (11h 24m 08.89s , -09d 52m 16.9s) |   C |    60 | 17.3 |        
    2539 | 2020-06-04 20:41:54 |         MASTER-SAAO | (11h 17m 07.71s , -09d 53m 35.1s) |   C |    60 | 17.4 |        
    2619 | 2020-06-04 20:43:14 |         MASTER-SAAO | (11h 20m 15.52s , -07d 53m 17.8s) |   C |    60 | 16.5 |        
    2619 | 2020-06-04 20:43:14 |         MASTER-SAAO | (11h 13m 16.69s , -07d 54m 36.0s) |   C |    60 | 17.0 |        
    2699 | 2020-06-04 20:44:33 |         MASTER-SAAO | (11h 29m 39.99s , +00d 07m 31.8s) |   C |    60 | 16.6 |        
    2699 | 2020-06-04 20:44:33 |         MASTER-SAAO | (11h 22m 45.31s , +00d 06m 12.9s) |   C |    60 | 16.7 |        
    2755 | 2020-06-04 20:45:30 |   MASTER-Kislovodsk | (11h 40m 12.42s , -00d 00m 40.0s) |   C |    60 | 14.1 |        
    2778 | 2020-06-04 20:45:53 |         MASTER-SAAO | (11h 15m 18.14s , -03d 51m 35.6s) |   C |    60 | 16.6 |        
    2858 | 2020-06-04 20:47:12 |         MASTER-SAAO | (11h 24m 07.10s , -09d 53m 10.3s) |   C |    60 | 17.2 |        
    2858 | 2020-06-04 20:47:12 |         MASTER-SAAO | (11h 17m 05.85s , -09d 54m 27.6s) |   C |    60 | 17.0 |        
    2938 | 2020-06-04 20:48:32 |         MASTER-SAAO | (12h 03m 27.09s , -03d 50m 31.3s) |   C |    60 | 17.5 |        
    2938 | 2020-06-04 20:48:32 |         MASTER-SAAO | (11h 56m 30.98s , -03d 51m 48.0s) |   C |    60 | 17.2 |        
    3017 | 2020-06-04 20:49:52 |         MASTER-SAAO | (11h 56m 31.63s , -09d 51m 44.8s) |   C |    60 | 17.4 |        
    3017 | 2020-06-04 20:49:52 |         MASTER-SAAO | (11h 49m 30.04s , -09d 53m 00.7s) |   C |    60 | 17.1 |        
    3097 | 2020-06-04 20:51:12 |         MASTER-SAAO | (11h 14m 01.63s , -01d 51m 36.1s) |   C |    60 | 16.2 |        
    3177 | 2020-06-04 20:52:32 |         MASTER-SAAO | (12h 05m 40.98s , -05d 51m 16.4s) |   C |    60 | 17.3 |        
    3177 | 2020-06-04 20:52:32 |         MASTER-SAAO | (11h 58m 43.52s , -05d 52m 32.7s) |   C |    60 | 17.1 |        
    3238 | 2020-06-04 20:53:32 |   MASTER-Kislovodsk | (12h 12m 37.53s , +01d 59m 42.0s) |   C |    60 | 16.6 |        
    3257 | 2020-06-04 20:53:51 |         MASTER-SAAO | (12h 03m 21.61s , -03d 52m 09.9s) |   C |    60 | 17.5 |        
    3257 | 2020-06-04 20:53:51 |         MASTER-SAAO | (11h 56m 25.45s , -03d 53m 26.6s) |   C |    60 | 17.3 |        
    3318 | 2020-06-04 20:54:53 |   MASTER-Kislovodsk | (12h 00m 10.02s , +05d 59m 17.1s) |   C |    60 | 15.4 |        
    3337 | 2020-06-04 20:55:11 |         MASTER-SAAO | (11h 56m 38.57s , -09d 52m 36.6s) |   C |    60 | 17.8 |        
    3337 | 2020-06-04 20:55:11 |         MASTER-SAAO | (11h 49m 36.95s , -09d 53m 52.4s) |   C |    60 | 17.1 |        
    3398 | 2020-06-04 20:56:13 |   MASTER-Kislovodsk | (12h 14m 02.63s , +03d 59m 04.6s) |   C |    60 | 17.0 |        
    3417 | 2020-06-04 20:56:31 |         MASTER-SAAO | (11h 14m 04.32s , -01d 52m 05.9s) |   C |    60 | 16.9 |        
    3496 | 2020-06-04 20:57:51 |         MASTER-SAAO | (12h 05m 37.70s , -05d 52m 04.3s) |   C |    60 | 17.4 |        
    3496 | 2020-06-04 20:57:51 |         MASTER-SAAO | (11h 58m 40.22s , -05d 53m 20.4s) |   C |    60 | 17.1 |        
    3559 | 2020-06-04 20:58:54 |   MASTER-Kislovodsk | (12h 12m 42.50s , +02d 00m 26.2s) |   C |    60 | 15.7 |        
    3576 | 2020-06-04 20:59:11 |         MASTER-SAAO | (12h 02m 07.33s , -01d 50m 12.0s) |   C |    60 | 16.6 |        
    3576 | 2020-06-04 20:59:11 |         MASTER-SAAO | (11h 55m 11.97s , -01d 51m 28.5s) |   C |    60 | 16.9 |        
    3656 | 2020-06-04 21:00:30 |         MASTER-SAAO | (11h 45m 06.76s , -11d 52m 19.2s) |   C |    60 | 17.2 |        
    3656 | 2020-06-04 21:00:30 |         MASTER-SAAO | (11h 38m 02.35s , -11d 53m 34.7s) |   C |    60 | 17.3 |        
    3736 | 2020-06-04 21:01:50 |         MASTER-SAAO | (11h 28m 45.54s , -11d 51m 44.1s) |   C |    60 | 17.5 |        
    3736 | 2020-06-04 21:01:50 |         MASTER-SAAO | (11h 21m 41.28s , -11d 53m 00.0s) |   C |    60 | 17.5 |        
    4982 | 2020-06-04 21:22:36 |          MASTER-IAC | (11h 37m 25.56s , -07d 53m 05.4s) |   C |    60 | 17.8 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200604A
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27890
SUBJECT: GRB 200604A: AstroSat CZTI detection
DATE:    20/06/05 10:15:56 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the weak detection of a long GRB 200604A, which was also detected by Fermi GBM (GCN #27887) and Global MASTER-Net (Lipunov V. et al., GCN # 27888).

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-06-04 20:00:02.520 UT. The measured peak count rate associated with the burst is 174 +/- 26 cts/s above the background in the combined data of four quadrants, with a total of 780 +/- 20 cts. The local mean background count rate was 516 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 12.77 +/- 0.06 s. In preliminary analysis, we find that 605 Compton events are associated with this event.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200530A
Detection_method: Fermi LAT Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27891
SUBJECT: GRB 200530A: Fermi-LAT detection
DATE:    20/06/05 18:03:00 GMT
FROM:    Francesco Longo at U of Trieste,INFN Trieste  <franzlongo1969@gmail.com>

F. Longo (University and INFN, Trieste), D. Kocevski (NASA/MSFC), N. Di
Lalla (Stanford University),
M. Ohno (Hiroshima Univ.), F. Fana Dirirsa (Univ. of Johannesburg), N.
Omodei (Stanford University)
and J. Racusin (NASA/GSFC) report on behalf of the Fermi-LAT Collaboration:

On May 30, 2020, Fermi-LAT detected high-energy emission from
GRB 200530A, which was also detected by Fermi-GBM at T0 = 00:44:10 UT (GCN
27861).

The GRB is detected at high energy (>100 MeV) by Fermi-LAT at a location of:
RA, Dec = 32.1, 69.2 (degrees, J2000) with an error radius of 0.5 deg
(90% containment, statistical error only).
This was ~40 deg from the LAT boresight when observations started,
and is ~6 deg from the GBM final ground position.
The photon flux above 100 MeV in the time interval 0 - 1000 s
after the GBM trigger is 5.5 e-06 +/- 1.8 e-06 ph/cm2/s.
The estimated photon index above 100 MeV is -2.3 +/- 0.3.
The highest-energy photon is a 1.6 GeV event which is observed
~100 seconds after the GBM trigger.
After ~T0+1000 s, the GRB location moved outside the LAT FoV.
When it re-entered in the LAT FoV at later times (from ~4800  to ~6700 s)
it was not detected.

The late time notification of this detection is due to a delay on the data
processing for the data of May 30.

The Fermi-LAT point of contact for this burst is
Francesco Longo (francesco.longo@ts.infn.it).

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: GRB200605A
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27892
SUBJECT: GRB 200605A: Fermi GBM Final Real-time Localization
DATE:    20/06/05 18:28:02 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 SHORT GRB

At 18:17:42 UT on 5 Jun 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200605A (trigger 613073867.194696 / 200605762).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 93.0, Dec = 53.6 (J2000 degrees, equivalent to J2000 06h 12m, 53d 36'), with a statistical uncertainty of 3.5 degrees.

The angle from the Fermi LAT boresight is 46.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200605762/quicklook/glg_skymap_all_bn200605762.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200605762/quicklook/glg_healpix_all_bn200605762.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200605762/quicklook/glg_lc_medres34_bn200605762.gif


GRB_name: GRB200605A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27893
SUBJECT: Fermi GRB 200605A: Global MASTER-Net observations report 
DATE:    20/06/05 18:45:41 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

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




MASTER-Kislovodsk robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 200605A ( Fermi GBM team, GCN 27892) errorbox  83 sec after notice time and 111 sec after trigger time at 2020-06-05 18:19:33 UT, with upper limit up to  18.0 mag. Observations started at twilight.  The observations began at zenith distance = 74 deg. The sun  altitude  is -13.6 deg. 

MASTER-Tavrida robotic telescope  located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 200605A errorbox  1260 sec after notice time and 1288 sec after trigger time at 2020-06-05 18:39:10 UT, with upper limit up to  16.1 mag. Observations started at twilight.  The observations began at zenith distance = 70 deg. The sun  altitude  is -11.4 deg. 

The galactic latitude b = 17 deg., longitude l = 161 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1374749

We obtain a following upper limits.  

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

     121 | 2020-06-05 18:19:33 |   MASTER-Kislovodsk | (06h 07m 39.57s , +49d 27m 34.6s) |   C |    20 | 16.6 |        
     156 | 2020-06-05 18:19:33 |   MASTER-Kislovodsk | (06h 07m 39.57s , +49d 27m 34.6s) |   C |    90 | 17.5 |  Coadd 
     167 | 2020-06-05 18:20:13 |   MASTER-Kislovodsk | (06h 07m 44.61s , +49d 28m 01.0s) |   C |    30 | 16.8 |        
     222 | 2020-06-05 18:21:04 |   MASTER-Kislovodsk | (06h 07m 42.78s , +49d 29m 23.4s) |   C |    40 | 16.9 |        
     287 | 2020-06-05 18:22:04 |   MASTER-Kislovodsk | (06h 07m 42.56s , +49d 27m 30.3s) |   C |    50 | 17.0 |        
     362 | 2020-06-05 18:23:14 |   MASTER-Kislovodsk | (06h 07m 44.75s , +49d 29m 07.2s) |   C |    60 | 17.0 |        
     635 | 2020-06-05 18:27:17 |   MASTER-Kislovodsk | (06h 18m 33.37s , +53d 25m 33.8s) |   C |   120 | 17.3 |        
     790 | 2020-06-05 18:27:17 |   MASTER-Kislovodsk | (06h 18m 33.37s , +53d 25m 33.8s) |   C |   430 | 18.0 |  Coadd 
     786 | 2020-06-05 18:29:38 |   MASTER-Kislovodsk | (06h 18m 30.63s , +53d 26m 34.7s) |   C |   140 | 17.4 |        
     961 | 2020-06-05 18:32:18 |   MASTER-Kislovodsk | (06h 18m 30.43s , +53d 25m 04.7s) |   C |   170 | 17.4 |        
    1157 | 2020-06-05 18:35:29 |   MASTER-Kislovodsk | (06h 18m 33.67s , +53d 26m 26.9s) |   C |   180 | 17.4 |        
    1298 | 2020-06-05 18:38:49 |   MASTER-Kislovodsk | (06h 18m 54.75s , +49d 51m 28.0s) |   C |    60 | 17.1 |        
    1319 | 2020-06-05 18:39:10 |      MASTER-Tavrida | (06h 07m 53.07s , +51d 59m 35.0s) |   C |    60 | 16.1 |        
    1378 | 2020-06-05 18:40:10 |   MASTER-Kislovodsk | (06h 06m 27.94s , +49d 52m 07.6s) |   C |    60 | 17.1 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200530A
Detection_method: CALET
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27896
SUBJECT: GRB 200530A: CALET Gamma-Ray Burst Monitor detection
DATE:    20/06/06 12:01:09 GMT
FROM:    Valentin Pal'shin at AGU  <val@phys.aoyama.ac.jp>

S. Sugita, A. Yoshida, T. Sakamoto, V. Pal'shin (AGU),
Y. Kawakubo (LSU), K. Yamaoka (Nagoya U), S. Nakahira (RIKEN),
Y. Asaoka, S. Torii (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 200530A (Fermi GBM Localization: the Fermi GBM team,
GCN Circ. 27861; AstroSat CZTI detection: Gupta et al., GCN Circ. 27864;
Fermi-LAT detection: Longo et al., GCN Circ. 27891;
https://gcn.gsfc.nasa.gov/other/200530A.gcn3) triggered the CALET
Gamma-ray Burst Monitor (CGBM) at 00:44:15.067 UTC on 30 May 2020.
The burst signal was seen by all CGBM detectors.
Because of a problem in one of the ground alert processing script, the GCN
notice was not distributed automatically for this event.

The burst light curve shows a multi-peaked structure which starts at
T-2.9 sec, peaks at T+5.6 sec and ends at T+21.1 sec. The T90 and T50
durations measured by the SGM data are 19.7 +- 2.0 sec and 9.5 +- 0.9 sec
(40-1000 keV), respectively.

The ground processed light curve is available at

http://cgbm.calet.jp/cgbm_trigger/ground/1274834660/

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


GRB_name: GRB200530A
Detection_method: Fermi GBM Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27897
SUBJECT: GRB 200530A: Fermi GBM detection
DATE:    20/06/06 23:30:30 GMT
FROM:    Joshua Wood at MSFC/Fermi-GBM  <joshua.r.wood@nasa.gov>

J. Wood (NASA/MSFC) and C. Meegan (UAH) report on behalf of the Fermi GBM Team:

"At 00:44:10.57 UT on 30 May 2020, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 200530A (trigger 612492255 / GBM200530031),
which was also detected by the Fermi/LAT (Longo et al. 2020, GCN 27891)
The Fermi GBM Final Real-time Localization is consistent with the LAT position.

The angle from the Fermi LAT boresight at the GBM trigger time is 41 degrees.

The GBM light curve shows a multi-peaked structure
with a duration (T90) of about 23 s (50-300 keV).
The time-averaged spectrum from T0-1.5 s to T0+28.2 s is
best fit by a power law function with an exponential high-energy cutoff.
The power law index is -0.55 +/- 0.02 and the cutoff energy, parameterized
as Epeak, is 178 +/- 4 keV.

The event fluence (10-1000 keV) in this time interval is
(2.27 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+10.0 s in the 10-1000 keV band
is 10.9 +/- 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: GRB200607A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27898
SUBJECT: GRB 200607A: BALROG localization (Fermi Trigger 613212114 / GRB 200607362)
DATE:    20/06/07 09:06:43 GMT
FROM:    Jochen Greiner at MPE,Garching  <jcg@mpe.mpg.de>

B. Biltzinger, F. Kunzweiler, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:

The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger
613212114 at 08:41:49 on 07 June 2020 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) = 183.8+/-5.8 deg
Decl.(2000.0) = 18.1+/-2.4 deg
We estimate an additional systematic error of 2 deg.

Further details are available at:
https://grb.mpe.mpg.de/grb/GRB200607362/

The Healpix map can be downloaded from:
https://grb.mpe.mpg.de/grb/GRB200607362/healpix

The location parameters are available as JSON at:
https://grb.mpe.mpg.de/grb/GRB200607362/json

                        


GRB_name: GRB200607A
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27899
SUBJECT: GRB 200607A: Fermi GBM Final Localization
DATE:    20/06/07 12:59:17 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

B. Mailyan (IBS, South Korea) reports on behalf of the Fermi GBM Team:

"
At 08:41:49.66 UT on 7 June 2020, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 200607A (trigger 613212114 / 200607362).

The on-ground calculated location, using the Fermi GBM trigger data, is RA =
171.5, Dec = +30.88 (J2000 degrees, equivalent to J2000 11h 26m, -30d
52'), with a statistical uncertainty of 2.1 degrees.

The angle from the Fermi LAT boresight is 80 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200607362/quicklook/glg_skymap_all_bn200607362.png

The HEALPix FITS file, including the estimated localization systematic, can
be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200607362/quicklook/glg_healpix_all_bn200607362.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200607362/quicklook/glg_lc_medres34_bn200607362.gif
"


GRB_name: GRB200605A
Detection_method: IPN Triangulation
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27900
SUBJECT: IPN triangulation of GRB 200605A (short)
DATE:    20/06/07 17:20:20 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

K. Hurley, on behalf of the IPN,

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

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Ridnaia,
and T. Cline on behalf of the Konus-Wind team,

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

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

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

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

The short-duration GRB 200605A
(Fermi-GBM detection: The Fermi GBM team, GCN Circ. 27892)
has been detected by Fermi (GBM trigger 613073867), Konus-Wind,
INTEGRAL (SPI-ACS), Mars-Odyssey (HEND), and Swift (BAT), so far,
at about 65862 s UT (18:17:42).
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:
    95.839 (06h 23m 21s) +50.954 (+50d 57' 14")
  Corners:
    96.116 (06h 24m 28s) +51.192 (+51d 11' 29")
    95.683 (06h 22m 44s) +51.188 (+51d 11' 16")
    95.565 (06h 22m 16s) +50.715 (+50d 42' 52")
    95.993 (06h 23m 58s) +50.719 (+50d 43' 09")
  ---------------------------------------------
The error box area is 460 sq. arcmin, and its maximum
dimension is 35 arcmin (the minimum one is 16 arcmin).
The Sun distance was 33 deg.

This box may be improved.

The IPN localization is consistent with, but reduces the area of, the 
Fermi-GBM final position (GCN Circ. 27892).

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB200605_T65862/IPN

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

The Swift (BAT) event data used for the IPN localization
came from the GUANO system (https://www.swift.psu.edu/guano/).


GRB_name: GRB200607A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27901
SUBJECT: Fermi GRB 200607A: Global MASTER-Net observations report 
DATE:    20/06/07 18:15:14 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200607A ( B. Mailyan et al., GCN 27899) errorbox  30030 sec after notice time and 30057 sec after trigger time at 2020-06-07 17:02:46 UT, with upper limit up to  18.4 mag. Observations started at twilight.  The observations began at zenith distance = 64 deg. The sun  altitude  is -16.2 deg. 

MASTER-SAAO robotic telescope  located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 200607A errorbox  32194 sec after notice time and 32220 sec after trigger time at 2020-06-07 17:38:50 UT, with upper limit up to  19.2 mag. The observations began at zenith distance = 67 deg. The sun  altitude  is -24.3 deg. 

The galactic latitude b = 65 deg., longitude l = 185 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1375841

We obtain a following upper limits.  

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

   30087 | 2020-06-07 17:02:46 |        MASTER-Tunka | (11h 19m 14.79s , +30d 21m 40.1s) |   C |    60 | 17.9 |        
   30167 | 2020-06-07 17:04:06 |        MASTER-Tunka | (11h 14m 51.86s , +32d 21m 30.0s) |   C |    60 | 17.9 |        
   30246 | 2020-06-07 17:05:25 |        MASTER-Tunka | (11h 33m 43.72s , +32d 21m 06.8s) |   C |    60 | 18.4 |        
   30326 | 2020-06-07 17:06:45 |        MASTER-Tunka | (11h 24m 24.95s , +28d 20m 56.0s) |   C |    60 | 17.8 |        
   30405 | 2020-06-07 17:08:04 |        MASTER-Tunka | (11h 19m 20.60s , +30d 22m 29.1s) |   C |    60 | 18.0 |        
   30484 | 2020-06-07 17:09:24 |        MASTER-Tunka | (11h 28m 28.91s , +30d 21m 46.8s) |   C |    60 | 18.0 |        
   30564 | 2020-06-07 17:10:43 |        MASTER-Tunka | (11h 14m 45.38s , +32d 22m 20.8s) |   C |    60 | 17.7 |        
   30644 | 2020-06-07 17:12:03 |        MASTER-Tunka | (11h 24m 18.98s , +32d 21m 35.8s) |   C |    60 | 18.0 |        
   30723 | 2020-06-07 17:13:22 |        MASTER-Tunka | (11h 33m 38.38s , +32d 20m 49.9s) |   C |    60 | 18.2 |        
   30803 | 2020-06-07 17:14:42 |        MASTER-Tunka | (11h 43m 10.17s , +32d 21m 22.2s) |   C |    60 | 18.0 |        
   30882 | 2020-06-07 17:16:01 |        MASTER-Tunka | (11h 24m 25.14s , +28d 22m 24.4s) |   C |    60 | 17.8 |        
   30961 | 2020-06-07 17:17:21 |        MASTER-Tunka | (11h 33m 29.44s , +28d 20m 46.2s) |   C |    60 | 17.9 |        
   31041 | 2020-06-07 17:18:40 |        MASTER-Tunka | (11h 28m 35.94s , +30d 22m 04.4s) |   C |    60 | 18.0 |        
   31120 | 2020-06-07 17:19:59 |        MASTER-Tunka | (11h 24m 11.55s , +32d 21m 24.4s) |   C |    60 | 18.0 |        
   31200 | 2020-06-07 17:21:19 |        MASTER-Tunka | (11h 43m 05.54s , +32d 22m 55.7s) |   C |    60 | 18.1 |        
   31279 | 2020-06-07 17:22:38 |        MASTER-Tunka | (11h 33m 31.20s , +28d 21m 37.6s) |   C |    60 | 17.8 |        
   32167 | 2020-06-07 17:37:26 |        MASTER-Tunka | (11h 37m 45.49s , +30d 21m 29.3s) |   C |    60 | 17.6 |        
   32247 | 2020-06-07 17:38:46 |        MASTER-Tunka | (11h 30m 21.13s , +34d 21m 12.3s) |   C |    60 | 18.0 |        
   32251 | 2020-06-07 17:38:50 |         MASTER-SAAO | (11h 18m 09.28s , +34d 09m 11.2s) |   C |    60 | 19.0 |        
   32251 | 2020-06-07 17:38:50 |         MASTER-SAAO | (11h 09m 51.38s , +34d 07m 44.7s) |   C |    60 | 19.0 |        
   32326 | 2020-06-07 17:40:05 |        MASTER-Tunka | (11h 06m 21.84s , +28d 19m 24.5s) |   C |    60 | 17.5 |        
   32331 | 2020-06-07 17:40:10 |         MASTER-SAAO | (11h 07m 30.94s , +30d 08m 33.1s) |   C |    60 | 18.9 |        
   32331 | 2020-06-07 17:40:10 |         MASTER-SAAO | (10h 59m 34.25s , +30d 07m 07.5s) |   C |    60 | 18.8 |        
   32406 | 2020-06-07 17:41:25 |        MASTER-Tunka | (11h 27m 35.75s , +36d 20m 08.2s) |   C |    60 | 17.9 |        
   32411 | 2020-06-07 17:41:30 |         MASTER-SAAO | (11h 36m 37.53s , +26d 09m 17.8s) |   C |    60 | 18.7 |        
   32411 | 2020-06-07 17:41:30 |         MASTER-SAAO | (11h 28m 57.87s , +26d 07m 55.8s) |   C |    60 | 18.9 |        
   32485 | 2020-06-07 17:42:44 |        MASTER-Tunka | (11h 37m 50.10s , +30d 22m 15.2s) |   C |    60 | 17.9 |        
   32490 | 2020-06-07 17:42:50 |         MASTER-SAAO | (11h 49m 16.33s , +28d 08m 10.9s) |   C |    60 | 18.7 |        
   32490 | 2020-06-07 17:42:50 |         MASTER-SAAO | (11h 41m 28.53s , +28d 06m 49.8s) |   C |    60 | 18.7 |        
   32565 | 2020-06-07 17:44:04 |        MASTER-Tunka | (11h 46m 59.78s , +30d 21m 31.3s) |   C |    60 | 17.7 |        
   32570 | 2020-06-07 17:44:09 |         MASTER-SAAO | (11h 18m 02.35s , +34d 07m 25.9s) |   C |    60 | 19.0 |        
   32570 | 2020-06-07 17:44:09 |         MASTER-SAAO | (11h 09m 44.67s , +34d 06m 01.5s) |   C |    60 | 18.9 |        
   32644 | 2020-06-07 17:45:23 |        MASTER-Tunka | (11h 30m 15.79s , +34d 22m 00.8s) |   C |    60 | 17.9 |        
   32650 | 2020-06-07 17:45:29 |         MASTER-SAAO | (11h 07m 36.83s , +30d 07m 40.5s) |   C |    60 | 19.0 |        
   32650 | 2020-06-07 17:45:30 |         MASTER-SAAO | (10h 59m 40.20s , +30d 06m 16.6s) |   C |    60 | 18.9 |        
   32724 | 2020-06-07 17:46:43 |        MASTER-Tunka | (11h 40m 00.84s , +34d 21m 15.6s) |   C |    60 | 18.1 |        
   32804 | 2020-06-07 17:48:03 |        MASTER-Tunka | (11h 06m 14.98s , +28d 19m 11.4s) |   C |    60 | 17.3 |        
   32883 | 2020-06-07 17:49:22 |        MASTER-Tunka | (11h 15m 25.37s , +28d 19m 53.6s) |   C |    60 | 17.3 |        
   32930 | 2020-06-07 17:50:09 |         MASTER-SAAO | (11h 36m 40.95s , +26d 07m 48.5s) |   C |    60 | 18.7 |        
   32930 | 2020-06-07 17:50:09 |         MASTER-SAAO | (11h 29m 01.27s , +26d 06m 25.9s) |   C |    60 | 18.9 |        
   32964 | 2020-06-07 17:50:43 |        MASTER-Tunka | (11h 27m 35.91s , +36d 21m 28.5s) |   C |    60 | 17.7 |        
   33010 | 2020-06-07 17:51:29 |         MASTER-SAAO | (11h 49m 15.77s , +28d 09m 04.8s) |   C |    60 | 18.9 |        
   33010 | 2020-06-07 17:51:29 |         MASTER-SAAO | (11h 41m 27.84s , +28d 07m 43.1s) |   C |    60 | 18.8 |        
   33044 | 2020-06-07 17:52:03 |        MASTER-Tunka | (11h 37m 29.56s , +36d 20m 15.5s) |   C |    60 | 17.8 |        
   33089 | 2020-06-07 17:52:48 |         MASTER-SAAO | (11h 18m 47.72s , +26d 08m 48.3s) |   C |    60 | 19.1 |        
   33089 | 2020-06-07 17:52:48 |         MASTER-SAAO | (11h 11m 08.05s , +26d 07m 25.5s) |   C |    60 | 19.1 |        
   33123 | 2020-06-07 17:53:22 |        MASTER-Tunka | (11h 47m 05.33s , +30d 22m 13.3s) |   C |    60 | 17.6 |        
   33169 | 2020-06-07 17:54:08 |         MASTER-SAAO | (11h 02m 47.77s , +32d 09m 41.7s) |   C |    60 | 18.7 |        
   33169 | 2020-06-07 17:54:08 |         MASTER-SAAO | (10h 54m 40.93s , +32d 08m 17.6s) |   C |    60 | 18.6 |        
   33203 | 2020-06-07 17:54:42 |        MASTER-Tunka | (11h 39m 54.98s , +34d 21m 00.3s) |   C |    60 | 17.9 |        
   33249 | 2020-06-07 17:55:28 |         MASTER-SAAO | (11h 15m 07.39s , +36d 08m 25.0s) |   C |    60 | 18.7 |        
   33249 | 2020-06-07 17:55:28 |         MASTER-SAAO | (11h 06m 37.38s , +36d 07m 01.7s) |   C |    60 | 18.6 |        
   33282 | 2020-06-07 17:56:01 |        MASTER-Tunka | (11h 15m 18.72s , +28d 21m 14.0s) |   C |    60 | 17.3 |        
   33329 | 2020-06-07 17:56:48 |         MASTER-SAAO | (11h 51m 23.87s , +32d 05m 58.8s) |   C |    60 | 18.6 |        
   33362 | 2020-06-07 17:57:21 |        MASTER-Tunka | (11h 37m 31.97s , +36d 20m 51.7s) |   C |    60 | 17.8 |        
   33441 | 2020-06-07 17:58:41 |        MASTER-Tunka | (11h 49m 41.09s , +34d 20m 20.6s) |   C |    60 | 17.5 |        
   33521 | 2020-06-07 18:00:00 |        MASTER-Tunka | (11h 25m 36.72s , +38d 19m 55.1s) |   C |    60 | 17.6 |        
   33569 | 2020-06-07 18:00:48 |         MASTER-SAAO | (11h 02m 50.33s , +32d 09m 39.3s) |   C |    60 | 18.7 |        
   33569 | 2020-06-07 18:00:48 |         MASTER-SAAO | (10h 54m 43.55s , +32d 08m 16.5s) |   C |    60 | 18.5 |        
   33607 | 2020-06-07 18:01:26 |        MASTER-Tunka | (10h 51m 38.61s , +34d 19m 18.5s) |   C |    60 | 17.1 |        
   33649 | 2020-06-07 18:02:08 |         MASTER-SAAO | (11h 15m 04.89s , +36d 07m 43.4s) |   C |    60 | 18.5 |        
   33649 | 2020-06-07 18:02:08 |         MASTER-SAAO | (11h 06m 35.02s , +36d 06m 21.1s) |   C |    60 | 18.6 |        
   33729 | 2020-06-07 18:03:28 |         MASTER-SAAO | (11h 59m 36.26s , +32d 09m 02.7s) |   C |    60 | 18.5 |        
   33729 | 2020-06-07 18:03:28 |         MASTER-SAAO | (11h 51m 29.42s , +32d 07m 44.0s) |   C |    60 | 18.6 |        
   33809 | 2020-06-07 18:04:48 |         MASTER-SAAO | (11h 17m 45.36s , +24d 07m 42.0s) |   C |    60 | 19.2 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200607B
Detection_method: Fermi GBM final loc
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27902
SUBJECT: GRB 200607B: Fermi GBM Final Real-time Localization
DATE:    20/06/07 22:16:55 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 22:06:31 UT on 7 Jun 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200607B (trigger 613260396.424964 / 200607921).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 41.3, Dec = -83.3 (J2000 degrees, equivalent to J2000 02h 45m, -83d 17'), with a statistical uncertainty of 1.0 degrees.

The angle from the Fermi LAT boresight is 20.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200607921/quicklook/glg_skymap_all_bn200607921.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200607921/quicklook/glg_healpix_all_bn200607921.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200607921/quicklook/glg_lc_medres34_bn200607921.gif


GRB_name: GRB200607B
Detection_method: Fermi GBM Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27903
SUBJECT: Fermi GRB 200607B: Global MASTER-Net observations report 
DATE:    20/06/07 22:30:28 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, 
V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva,
D.Kuvshinov,  D. Cheryasov
(Lomonosov Moscow State University, SAI, Physics Department),

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

H.Levato 
(Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE),

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

D. Buckley 
(South African Astronomical Observatory),

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko 
(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 200607B ( Fermi GBM team, GCN 27902) errorbox  24 sec after notice time and 53 sec after trigger time at 2020-06-07 22:07:24 UT, with upper limit up to  17.8 mag. The observations began at zenith distance = 62 deg. The sun  altitude  is -78.6 deg. 

The galactic latitude b = -33 deg., longitude l = 301 deg.


Real time updated cover map and OT discovered available here: 
https://master.sai.msu.ru/site/master2/observ.php?id=1376307

We obtain a following upper limits.  

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

      59 | 2020-06-07 22:07:24 |         MASTER-SAAO | (01h 30m 36.49s , -84d 13m 24.3s) |   C |    10 | 17.3 |        
      59 | 2020-06-07 22:07:24 |         MASTER-SAAO | (02h 39m 16.16s , -84d 11m 05.2s) |   C |    10 | 17.4 |        
      88 | 2020-06-07 22:07:54 |         MASTER-SAAO | (01h 30m 26.70s , -84d 14m 22.9s) |   C |    10 | 17.3 |        
      88 | 2020-06-07 22:07:54 |         MASTER-SAAO | (02h 39m 18.22s , -84d 12m 04.0s) |   C |    10 | 17.5 |        
     123 | 2020-06-07 22:08:23 |         MASTER-SAAO | (02h 18m 05.68s , -83d 19m 14.7s) |  P/ |    20 | 16.5 |        
     123 | 2020-06-07 22:08:23 |         MASTER-SAAO | (03h 17m 34.57s , -83d 16m 55.7s) | P\  |    20 | 17.0 |        
     167 | 2020-06-07 22:09:03 |         MASTER-SAAO | (02h 18m 00.26s , -83d 20m 43.7s) |  P/ |    30 | 16.9 |        
     167 | 2020-06-07 22:09:03 |         MASTER-SAAO | (03h 17m 41.87s , -83d 18m 24.8s) | P\  |    30 | 17.0 |        
     221 | 2020-06-07 22:09:52 |         MASTER-SAAO | (02h 18m 08.05s , -83d 19m 17.0s) |  P/ |    40 | 17.0 |        
     221 | 2020-06-07 22:09:52 |         MASTER-SAAO | (03h 17m 36.50s , -83d 16m 57.9s) | P\  |    40 | 17.3 |        
     286 | 2020-06-07 22:10:52 |         MASTER-SAAO | (02h 26m 51.67s , -83d 13m 46.1s) |  P/ |    50 | 16.9 |        
     286 | 2020-06-07 22:10:52 |         MASTER-SAAO | (03h 18m 17.49s , -83d 25m 38.3s) | P\  |    50 | 17.3 |        
     382 | 2020-06-07 22:12:23 |         MASTER-SAAO | (03h 17m 30.22s , -83d 16m 50.8s) | P\  |    60 | 17.5 |        
     605 | 2020-06-07 22:15:41 |         MASTER-SAAO | (02h 18m 06.68s , -83d 19m 24.4s) |  P/ |   110 | 17.5 |        
     605 | 2020-06-07 22:15:41 |         MASTER-SAAO | (03h 17m 35.17s , -83d 17m 05.0s) | P\  |   110 | 17.8 |        
     745 | 2020-06-07 22:17:51 |         MASTER-SAAO | (02h 18m 02.11s , -83d 20m 47.6s) |  P/ |   130 | 17.5 |        
     745 | 2020-06-07 22:17:51 |         MASTER-SAAO | (03h 17m 42.85s , -83d 18m 28.6s) | P\  |   130 | 17.8 |        
Filter C is a clear (unfiltred) band. 


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


GRB_name: GRB200522A
Detection_method: Other
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27904
SUBJECT: GRB 200522A: Further HST F125W Observations
DATE:    20/06/08 02:28:35 GMT
FROM:    Charles Kilpatrick at UC Santa Cruz  <cdkilpat@ucsc.edu>

C. D. Kilpatrick (UCSC), J. Rastinejad, W. Fong (Northwestern), and E. Berger (Harvard) report on behalf of a larger collaboration:

"We report on further HST/WFC3 IR observations (PI: Berger; Program 15964) of the short GRB 200522A (Evans et al., GCN 27778). Subsequent to the previous F125W observations obtained 3.6 days post-burst (Fong et al., GCN 27826), we initiated a second epoch in the F125W filter starting on 2020 June 7.805 UT. A total of 4823-sec of exposure time was obtained (approximately 7 minutes shallower than the previous epoch), at a mid-time of ~16.4 days.

The previously-identified point-like Source C (Fong et al., GCN 27827) has an estimated m_f125W ~ 26.8 AB mag, fully consistent with our previous estimate. This indicates that this source has not faded and is unlikely to be related to the GRB.

To constrain the presence of any transient sources, we performed image subtraction between the two F125W epochs using the HOTPANTS software (Becker 2015). The difference image reveals low significance (<3 sigma) residuals, the brightest of which is located at RA = 00:22:43.62, Dec = -00:16:58.90 (J2000) with m_f125w = 28.1 AB mag.  This position is close to the LCO candidate (e.g., Strausbaugh et al., GCN 27792) but inconsistent with the VLA candidate (Fong et al., GCN 27786).

There are otherwise no obvious high-significance residuals consistent with the VLA or LCO candidates, or around the XRT position. We caution that the difference image is contaminated by the center of the bright galaxy, and analysis is ongoing. Firm conclusions will require a deep template observation.

We thank the HST staff for quickly implementing these observations."


GRB_name: GRB200607B
Detection_method: AstroSat CZTI
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27905
SUBJECT: GRB 200607B: AstroSat CZTI detection
DATE:    20/06/08 17:14:04 GMT
FROM:    Soumya Gupta at IUCAA/ASTROSAT  <soumya@iucaa>

S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:

Analysis of AstroSat CZTI data showed the detection of a long GRB 200607B, which was also detected by Fermi GBM (GCN #27902) and Global MASTER-Net (Lipunov V. et al., GCN # 27903).

The source was clearly detected in the 40-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2020-06-07 22:06:31.515 UT. The measured peak count rate associated with the burst is 688 +/- 35 cts/s above the background in the combined data of four quadrants, with a total of 5015 +/- 38 cts. The local mean background count rate was 549 +/- 1 cts/s. Using cumulative rates, we measure a T90 of 26.69 +/- 0.32 s.

It 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 2020-06-07 22:06:30.42 UT. The measured peak count rate is 743 +/- 41 cts/s above the background in the combined Veto data of four quadrants, with a total of 3041 +/- 120 cts. The local mean background count rate was 1662 +/- 7 cts/s.  We measure a T90 of 9.71 +/- 2.25 s from the cumulative Veto light curve.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.


GRB_name: GRB200608A
Detection_method: Swift Det
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27906
SUBJECT: GRB 200608A: Swift detection of a burst
DATE:    20/06/08 17:41:44 GMT
FROM:    David Palmer at LANL  <palmer@lanl.gov>

M. J. Moss (GWU), M. G. Bernardini (INAF-OAB), P. D'Avanzo (INAF-OAB),
J. A. Kennea (PSU), N. J. Klingler (PSU), S. Laha (GSFC/UMBC/CRESST),
A. Y. Lien (GSFC/UMBC), F. E. Marshall (NASA/GSFC),
K. L. Page (U Leicester), D. M. Palmer (LANL) and
T. Sbarrato (INAF-OAB) report on behalf of the Neil Gehrels Swift
Observatory Team:

At 17:28:38 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 200608A (trigger=976692).  Swift did not slew due to an
observing constraint. 
The BAT on-board calculated location is 
RA, Dec 309.629, -31.168 which is 
   RA(J2000) = 20h 38m 31s
   Dec(J2000) = -31d 10' 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 90 sec. However, we can not rule out
the possibility that some of these variations are from other sources in 
the field of view until further ground analysis. The peak count rate
was ~400 counts/sec (15-350 keV), at ~20 sec after the trigger. 

Due to a Moon observing constraint, Swift cannot slew to the BAT
position until 01:24 UT on 2020 June 11. There will thus be no XRT or
UVOT data for this trigger before this time. 

Burst Advocate for this burst is M. J. Moss (mikejmoss3 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: GRB200608A
Detection_method: Optical
Circular_text:
TITLE:   GCN CIRCULAR
NUMBER:  27907
SUBJECT: GRB 200608A: BOOTES-3 and BOOTES-4 optical upper limit
DATE:    20/06/08 22:00:00 GMT
FROM:    Youdong HU at IAA-CSIC  <youdong@iaa.es>

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC), I. 
Carrasco and C. Perez del Pulgar (Univ. de Malaga), M. D. 
Caballero-Garcia (ASU-CAS, CZ), R. Querel (NIWA), D. Xiong, Y. Fan, X. 
Zhao, J. Bai, C. Wang, Y. Xin (Yunnan Observatories of CAS), on behalf 
of a larger collaboration, report:

The 60cm BOOTES-3/YA robotic telescope at NIWA Lauder in Otago (New 
Zealand) responded to the Swift trigger of GRB 200608A (Moss et al. GCNC 
27906). The first image (clear filter) was obtained at 19:18:40 UT (~ 
1.83 hr after trigger). In the co-added image (5 exposures 30s each), no 
source is found at the region reported by Swift/BAT (Moss et al. GCNC 
27906) down to 17.4 mag.

The 60cm BOOTES-4/MET robotic telescope at Lijiang Astronomical 
Observatory (China) also gathered images starting at 19:32:24 UT (~ 2.06 
hr after trigger). No optical afterglow is found down to 18.1 mag 
(unfiltered images) within the Swift/BAT error box.

Both observations were severely affected by the presence of the moon 
about 13 degrees away. We thank the staff at NIWA and YNO for their 
excellent support.


