GRB230815A

This page lists all entries on GRB230815A in GRBweb

Summary Fermi GBM IPN Swift GCN 34434 GCN 34437 GCN 34439 GCN 34440 GCN 34441 GCN 34444 GCN 34446 GCN 34449 GCN 34452 GCN 34467 GCN 34518

Summary table
Variable Value Source
GRB_name_Fermi GRB230815451
T0 10:49:54.660 UTC GCN_circulars,Fermi GBM Det
ra 184.7222° Swift
decl -58.0529° Swift
pos_error 2.59e-04° Swift
T90 5.181 s Fermi_GBM
T90_error 0.859 s Fermi_GBM
T90_start 10:49:54.665 UTC Fermi_GBM
fluence 1.28e-05 erg/cm² Fermi_GBM
fluence_error 1.07e-07 erg/cm² Fermi_GBM
T100 17.34 s
GBM_located False
mjd 60171.451327083334 GCN_circulars,Fermi GBM Det
Fermi GBM table
GRB_name_Fermi GRB230815451
trigger_name bn230815451
ra 184.7229°
decl -58.0539°
datum 2023-08-15
t_trigger 10:49:54.662 UTC
T90 5.181 s
T90_error 0.859 s
T90_start 10:49:54.665 UTC
fluence 1.28e-05 erg/cm²
fluence_error 1.07e-07 erg/cm²
flux_1024 2.70e+01 erg/cm²/s
flux_1024_error 1.81e+00 erg/cm²/s
flux_1024_time 1.09e+00 erg/cm²/s
flux_64 3.94e+01 erg/cm²/s
flux_64_error 1.04e+01 erg/cm²/s
IPN table
GRB_name GRB230815A
ra 184.7250°
decl -58.0500°
pos_error 5.00e-02°
Swift table
GRB_name GRB230815A
t_trigger 10:49:55 UTC
ra 184.7222°
decl -58.0529°
pos_error 2.59e-04°
T90 17.0 s
fluence 5.20e-06 erg/cm²
GCN 34434 table
GRB_name GRB230815A
GCN_number 34434
Detection_method Swift Det
t_trigger 10:49:55 UTC
ra 184.7720°
decl -58.0650°
Circular_text TITLE: GCN CIRCULAR NUMBER: 34434 SUBJECT: GRB 230815A: Swift detection of a burst DATE: 23/08/15 11:25:59 GMT FROM: K.L. Page at U Leicester N. J. Klingler (GSFC/UMBC/CRESSTII), C. Gronwall (PSU), K. L. Page (U Leicester), D. M. Palmer (LANL) and T. M. Parsotan (GSFC/UMBC/CRESSTII) report on behalf of the Neil Gehrels Swift Observatory Team: At 10:49:55 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 230815A (trigger=1185505). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 184.772, -58.065 which is RA(J2000) = 12h 19m 05s Dec(J2000) = -58d 03' 53" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single-peaked structure with a duration of about 2 sec. The peak count rate was ~6000 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 10:52:04.0 UT, 128.1 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 184.72347, -58.05386 which is equivalent to: RA(J2000) = 12h 18m 53.63s Dec(J2000) = -58d 03' 13.9" with an uncertainty of 3.5 arcseconds (radius, 90% containment). This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (4.94 x 10^21 cm^-2, Willingale et al. 2013), with an excess column of 7.8 (+3.75/-3.24) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 2.07e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of 150 seconds with the White filter starting 155 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. Because of the density of catalogued stars, further analysis is required to report an upper limit for any afterglow in the sub-image. Data from the list of sources generated on-board are not available at this time. No correction has been made for the large, but uncertain, extinction expected. Burst Advocate for this burst is N. J. Klingler (noelklin AT umbc.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)
GCN 34437 table
GRB_name GRB230815A
GCN_number 34437
Detection_method Swift-XRT Det
ra 184.7223°
decl -58.0529°
Circular_text TITLE: GCN CIRCULAR NUMBER: 34437 SUBJECT: GRB 230815A: Enhanced Swift-XRT position DATE: 23/08/15 16:44:53 GMT FROM: Phil Evans at U of Leicester A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) report on behalf of the Swift-XRT team. Using 927 s of XRT Photon Counting mode data and 1 UVOT images for GRB 230815A, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 184.72225, -58.05290 which is equivalent to: RA (J2000): 12h 18m 53.34s Dec (J2000): -58d 03' 10.4" with an uncertainty of 2.2 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 34439 table
GRB_name GRB230815A
GCN_number 34439
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 34439 SUBJECT: Swift GRB 230815A: Global MASTER-Net observations report DATE: 23/08/15 19:54:30 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 230815A ( N. J. Klingler et al., GCN 34434) errorbox 27081 sec after notice time and 28191 sec after trigger time at 2023-08-15 18:41:55 UT, with upper limit up to 17.4 mag. The observations began at zenith distance = 58 deg. The sun altitude is -32.4 deg. The galactic latitude b = 4 deg., longitude l = 299 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2254590 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 28282 | MASTER-SAAO | C | 180 | 16.8 | 29125 | MASTER-SAAO | C | 180 | 17.4 | 29335 | MASTER-SAAO | C | 180 | 17.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 34440 table
GRB_name GRB230815A
GCN_number 34440
Detection_method Fermi GBM Det
t_trigger 10:49:54.660 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 34440 SUBJECT: GRB 230815A: Fermi GBM detection DATE: 23/08/15 20:38:44 GMT FROM: Bagrat Mailyan at Florida Tech B. Mailyan (Florida tech), A. von Kienlin (MPE) and C. Meegan (UAH) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 10:49:54.66 UT on 15 August 2023, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 230815A (trigger 713789399/230815451). which was also detected by Swift BAT (N. J. Klingler et al. 2023, GCN 34434). The Fermi GBM on-ground location is consistent with the Swift BAT position. The angle from the Fermi LAT boresight is 159 degrees. The GBM light curve consists of a single emission episode with a duration (T90) of about 5.2 s (50-300 keV). The time-averaged spectrum from T0+0.002 to T0+3.264 s is best fit by a Band function with Epeak = 235 +/- 25 keV, alpha = -0.6 +/- 0.1, and beta = -2.22 +/- 0.09. The event fluence (10-1000 keV) in this time interval is (1.20 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+1.1 s in the 10-1000 keV band is 27 +/- 2 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog: https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html For Fermi GBM data and info, please visit the official Fermi GBM Support Page: https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"
GCN 34441 table
GRB_name GRB230815A
GCN_number 34441
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 34441 SUBJECT: GRB230815A: BOOTES-6/DPRT optical upper limit DATE: 23/08/15 21:30:53 GMT FROM: Youdong HU at IAA-CSIC E. Fernandez-Garcia, Y.-D. Hu, I. Perez-Garcia, M.D. Caballero-Garcia, R. Sanchez-Ramirez, S. Guziy and A. J. Castro-Tirado (IAA-CSIC, Granada), P. J. Meintjes and H. J. van Heerden (UFS, SouthAfrica), A. Martin-Carrillo and L. Hanlon (UCD, Ireland) and C. J. Perez del Pulgar (UMA, Malaga), on behalf of a larger collaboration, report: Following the detection of GRB 230815A by Swift (Klingler et al. GCNC 34434) and Fermi (Mayland et al. GCNC 34440), the BOOTES-6/DPRT 0.6m robotic telescope at Boyden Observatory in Maselspoort (South Africa) automatically observed the GRB location starting on Aug. 15, 19:21 UT (~ 8.5 h after trigger). No new optical source is detected on the co-added image (5 x 60 s, clear filter) within the enhanced Swift/XRT error region (Beardmore et al. GCNC 34437) down to 19.5 mag. We thank the staff at Boyden Observatory for their excellent support.
GCN 34444 table
GRB_name GRB230815A
GCN_number 34444
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 34444 SUBJECT: GRB 230815A: Swift-XRT refined Analysis DATE: 23/08/16 05:16:53 GMT FROM: Phil Evans at U of Leicester P. D'Avanzo (INAF-OAB), M.G. Bernardini (INAF-OAB), D.N. Burrows (PSU), J. D. Gropp (PSU), S. Dichiara (PSU), J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), E. Ambrosi (INAF-IASFPA) and P.A. Evans report on behalf of the Swift-XRT team: We have analysed 6.0 ks of XRT data for GRB 230815A, from 117 s to 45.2 ks after the BAT trigger. The data comprise 574 s in Windowed Timing (WT) mode (the first 9 s were taken while Swift was slewing) with the remainder in Photon Counting (PC) mode. The late-time light curve (from T0+6.1 ks) can be modelled with a power-law decay with a decay index of alpha=1.94 (+0.25, -0.29). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.92 (+0.06, -0.05). The best-fitting absorption column is 7.4 (+0.5, -0.4) x 10^21 cm^-2, in excess of the Galactic value of 4.9 x 10^21 cm^-2 (Willingale et al. 2013). The PC mode spectrum has a photon index of 1.94 (+0.18, -0.17) and a best-fitting absorption column of 9.1 (+1.7, -1.5) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.9 x 10^-11 (8.5 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 9.1 (+1.7, -1.5) x 10^21 cm^-2 Galactic foreground: 4.9 x 10^21 cm^-2 Excess significance: 4.5 sigma Photon index: 1.94 (+0.18, -0.17) If the light curve continues to decay with a power-law decay index of 1.94, the count rate at T+24 hours will be 2.5 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.2 x 10^-13 (2.1 x 10^-13) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/01185505. This circular is an official product of the Swift-XRT team.
GCN 34446 table
GRB_name GRB230815A
GCN_number 34446
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 34446 SUBJECT: GRB230815A: Swift/UVOT upper limits DATE: 23/08/16 12:42:08 GMT FROM: Alice Breeveld at MSSL-UCL A. A. Breeveld (UCL-MSSL) and N. J. Klingler (GSFC/UMBC/CRESSTII) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 230815A 155 s after the BAT trigger (Klingler et al., GCN Circ. 34434). No optical afterglow consistent with the XRT position (Beardmore et al., GCN Circ. 34437) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first finding chart (FC) exposure and subsequent summed exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 155 305 147 >20.1 white 513 1531 242 >20.3 v 390 1582 136 >18.5 b 489 1506 114 >19.3 u 464 6300 293 >19.4 uvw1 439 1632 136 >18.6 uvm2 761 1606 97 >18.3 uvw2 365 1557 136 >18.8 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.73 in the direction of the burst (Schlegel et al. 1998).
GCN 34449 table
GRB_name GRB230815A
GCN_number 34449
Detection_method Swift-BAT Det
ra 184.7600°
decl -58.0670°
Circular_text TITLE: GCN CIRCULAR NUMBER: 34449 SUBJECT: GRB 230815A: Swift-BAT refined analysis DATE: 23/08/16 16:03:55 GMT FROM: Tyler Parsotan at NASA GSFC S. Laha (GSFC/UMBC), S. D. Barthelmy (GSFC), H. A. Krimm (NSF), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU) (i.e. the Swift-BAT team): Using the data set from T-240 to T+962 sec from the recent telemetry downlink, we report further analysis of BAT GRB 230815A (trigger #1185505) (Klingler, et al., GCN Circ. 34434). The BAT ground-calculated position is RA, Dec = 184.760, -58.067 deg which is RA(J2000) = 12h 19m 02.4s Dec(J2000) = -58d 03' 59.5" with an uncertainty of 1.2 arcmin, (radius, sys+stat, 90% containment). The partial coding was 11%. The mask-weighted light curve shows a strong peak at trigger time with precursor emission At T-14 sec from trigger. T90 (15-350 keV) is 17.00 +- 7.62 sec (estimated error including systematics). The time-averaged spectrum from T-14.78 to T+9.22 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.19 +- 0.10. The fluence in the 15-150 keV band is 5.2 +- 0.3 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+0.22 sec in the 15-150 keV band is 13.7 +- 1.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/1185505/BA/
GCN 34452 table
GRB_name GRB230815A
GCN_number 34452
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 34452 SUBJECT: GRB 230815A: SOAR/Goodman follow-up imaging DATE: 23/08/16 18:03:23 GMT FROM: Charles Kilpatrick at Northwestern U C. D. Kilpatrick (Northwestern), C. R. Bom (CBPF), A. Santos (CBPF/Fermilab), S. Panda (LNA), Felipe Navarete (NOIRLab/SOAR) on behalf of a larger collaboration, report: Following the detection of GRB230815A (Klingler et al., GCN 34434, Mailyan et al., GCN 34440), we triggered observations with the Goodman high-throughput imaging spectrograph on the SOAR 4.1m telescope at Cerro Pachón, Chile. Targeting the site of the reported Swift/XRT counterpart (Beardmore et al., GCN 34437), we obtained 6x180s exposures in SDSS i-band and 7x180s in SDSS z-band at start times of 2023-08-15 23:17:36 and 2023-08-15 23:50:48 UTC, respectively. We did not detect a counterpart in either stacked image, with the limiting magnitude in both frames significantly affected by poor atmospheric transparency. Performing forced photometry at the site of the XRT counterpart (R.A.=12:18:53.34, Decl.=-58:03:10.4), we derive limits on an optical counterpart of: MJD Filter Maglimit 60171.97055 i 20.5 60171.99361 z 17.9 Both magnitude limits are on the AB magnitude system calibrated from SkyMapper DR2 standard stars (Onken et al. 2019) and are not corrected for the significant Galactic extinction along this sight line (A_i=1.25 mag, A_z=0.93 mag). Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia e Inovações do Brasil (MCTI/LNA), the US National Science Foundation’s NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).
GCN 34467 table
GRB_name GRB230815A
GCN_number 34467
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 34467 SUBJECT: GRB 230815A: VLT/HAWK-I near-infrared afterglow detection DATE: 23/08/17 16:41:24 GMT FROM: Benjamin Schneider at MIT B. Schneider (MIT), A. Chrimes (Radboud), D. B. Malesani (Radboud and DAWN/NBI), A. J. Levan (Radboud), N. R. Tanvir (U. Leicester), A. de Ugarte Postigo (OCA/CNRS), report on behalf of the Stargate collaboration: We observed the field of GRB 230815A (Klingler et al., GCN 34434; Mailyan et al. GCN 34440) with the ESO Very Large Telescope, equipped with the HAWK-I near-infrared camera. Observations consisted of two epochs of 20 min exposure in the H band at 23:19:53 UT on 2023-08-15 (~12.5 hr after trigger) and 23:15:46 UT on 2023-08-16 (~36.4 hr after trigger). In both epochs, we clearly detected two sources consistent with the XRT error circle (Beardmore et al., GCN 34437). One of the sources has significantly faded (~2 mag) between the two epochs, evolving from AB mag = 20.11 +/- 0.02 to AB mag = 22.01 +/- 0.08. This corresponds to a power-law decay index of 1.65, similar to the X-ray decay rate, suggesting a small host contribution to the NIR flux. The proposed afterglow of the burst is detected at coordinates: RA (J2000) = 12:18:53.24 DEC (J2000) = -58:03:09.45 with an uncertainty of 0.3". We acknowledge the excellent support provided by the Paranal staff, in particular Joe Anderson.
GCN 34518 table
GRB_name GRB230815A
GCN_number 34518
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 34518 SUBJECT: GRB 230815A: ATCA detection of radio counterpart DATE: 23/08/22 11:44:32 GMT FROM: James Leung at U of Sydney/VAST J. K. Leung (USyd), G. E. Anderson (Curtin), S. D. Ryder (Macquarie), A. J. van der Horst (GWU), A. Gulati (USyd), L. Rhodes (Oxford), S. Chastain (UNM) on behalf of the PanRadio GRB collaboration The Australia Telescope Compact Array (ATCA) observed long GRB 230815A (Klingler et al., GCN 34434; Mailyan et al., GCN 34440) as part of the ATCA "PanRadio GRB" follow-up Large Project C3542 (PI. Anderson) on 2023-08-17 UT and 2023-08-18 UT. No radio sources were detected at the GRB location in the first observation conducted from 2023-08-17 02:00 UT for 10 hrs at 5.5, 9.0, 16.7 and 21.2 GHz. The 3-sigma upper limits were 75, 69, 324, 741 microJy/beam, respectively. Note the higher than usual rms was due to bad weather during the observation. The second observation was conducted from 2023-08-18 22:00 UT for 6 hrs at 5.5, 9.0 and 44 GHz. In our preliminary analysis, we detect a radio counterpart with a flux density of 70+/-10 microJy at 9 GHz. The fitted position is: RAJ2000 = 12:18:53.2 DECJ2000 = -58:03:09.0 with an uncertainty of ~0.3". This is in broad agreement with previously reported Swift/XRT (Beardmore et al., GCN 34437) and VLT/HAWK-I (Schneider et al., GCN 34467) afterglow positions. There was also a marginal ~3 sigma detection at 5.5 GHz (rms=14 microJy/beam) and a non-detection at 44 GHz with a 3-sigma upper limit of 111 microJy/beam. Further observations are planned. We thank the CSIRO Space and Astronomy staff for supporting these observations. We acknowledge the Gomeroi people as the traditional owners of the Observatory site. The Australia Telescope Compact Array is part of the Australia Telescope National Facility (https://ror.org/05qajvd42) which is funded by the Australian Government for operation as a National Facility managed by CSIRO.