GRB250509A

This page lists all entries on GRB250509A in GRBweb

Summary Fermi GBM IPN Swift GCN 40406 GCN 40407 GCN 40408 GCN 40409 GCN 40410 GCN 40411 GCN 40422 GCN 40456

Summary table
Variable Value Source
GRB_name_Fermi GRB250509940
T0 22:33:29 UTC GCN_circulars,Fermi GBM final loc
ra 46.4495° Swift
decl -38.8420° Swift
pos_error 2.72e-04° Swift
T90 69.12 s Fermi_GBM
T90_error 1.305 s Fermi_GBM
T90_start 22:33:29.286 UTC Fermi_GBM
fluence 6.42e-06 erg/cm² Fermi_GBM
fluence_error 3.13e-08 erg/cm² Fermi_GBM
T100 69.406 s
GBM_located False
mjd 60804.93991898148 GCN_circulars,Fermi GBM final loc
Fermi GBM table
GRB_name_Fermi GRB250509940
trigger_name bn250509940
ra 46.2296°
decl -38.8414°
pos_error 3.60e+00°
datum 2025-05-09
t_trigger 22:33:29.286 UTC
T90 69.12 s
T90_error 1.305 s
T90_start 22:33:29.286 UTC
fluence 6.42e-06 erg/cm²
fluence_error 3.13e-08 erg/cm²
flux_1024 3.62e+00 erg/cm²/s
flux_1024_error 3.40e-01 erg/cm²/s
flux_1024_time 6.21e+00 erg/cm²/s
flux_64 6.59e+00 erg/cm²/s
flux_64_error 1.50e+00 erg/cm²/s
IPN table
GRB_name GRB250509A
ra 46.4542°
decl -38.8500°
pos_error 5.00e-02°
Swift table
GRB_name GRB250509A
t_trigger 22:33:30 UTC
ra 46.4495°
decl -38.8420°
pos_error 2.72e-04°
GCN 40406 table
GRB_name GRB250509A
GCN_number 40406
Detection_method Fermi GBM final loc
t_trigger 22:33:29 UTC
ra 46.0000°
decl -35.3000°
Circular_text TITLE: GCN CIRCULAR NUMBER: 40406 SUBJECT: GRB 250509A: Fermi GBM Final Real-time Localization DATE: 25/05/09 22:43:58 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 22:33:29 UT on 9 May 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250509A (trigger 768522814.285632 / 250509940). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 46.0, Dec = -35.3 (J2000 degrees, equivalent to J2000 03h 04m, -35d 17'), with a statistical uncertainty of 3.0 degrees. The angle from the Fermi LAT boresight is 89.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250509940/quicklook/glg_skymap_all_bn250509940.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250509940/quicklook/glg_healpix_all_bn250509940.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250509940/quicklook/glg_lc_medres34_bn250509940.gif
GCN 40407 table
GRB_name GRB250509A
GCN_number 40407
Detection_method Swift Det
t_trigger 22:33:30 UTC
ra 46.4550°
decl -38.8530°
Circular_text TITLE: GCN CIRCULAR NUMBER: 40407 SUBJECT: GRB 250509A: Swift detection of a burst DATE: 25/05/09 22:49:14 GMT FROM: Mike Siegel at PSU/Swift MOC M. H. Siegel (PSU), S. Dichiara (PSU), R. Gupta (NASA GSFC) and B. Sbarufatti (INAF-OAB) report on behalf of the Neil Gehrels Swift Observatory Team: At 22:33:30 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 250509A (trigger=1311764). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 46.455, -38.853 which is RA(J2000) = 03h 05m 49s Dec(J2000) = -38d 51' 11" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a multi peak structure with a duration of about 60 sec. The peak count rate was ~2800 counts/sec (15-350 keV), at ~0 sec after the trigger. The XRT began observing the field at 22:34:41.7 UT, 71.1 seconds after the BAT trigger. Using promptly downlinked data we find a bright, uncatalogued X-ray source located at RA, Dec 46.45032, -38.84173 which is equivalent to: RA(J2000) = 03h 05m 48.08s Dec(J2000) = -38d 50' 30.2" with an uncertainty of 3.6 arcseconds (radius, 90% containment). This location is 42 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at https://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (2.03 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 9.2 (+3.98/-3.41) x 10^21 cm^-2 (90% confidence). The initial flux in the 2.5 s image was 7.21e-09 erg cm^-2 s^-1 (0.2-10 keV). UVOT took a finding chart exposure of nominal 150.000 seconds with the White filter starting 80 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. Data from the 2.7'x2.7' sub-image are not available at this time. 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 0.021. Burst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/)
GCN 40408 table
GRB_name GRB250509A
GCN_number 40408
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 40408 SUBJECT: Swift GRB 250509A: Global MASTER-Net observations report DATE: 25/05/09 23:06:47 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB 250509A ( M. H. Siegel et al., GCN 40407) errorbox 1296 sec after notice time and 1332 sec after trigger time at 2025-05-09 22:55:43 UT, with upper limit up to 18.4 mag. Observations started at twilight. The observations began at zenith distance = 76 deg. The sun altitude is -14.1 deg. The galactic latitude b = -59 deg., longitude l = 244 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2866479 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 1423 | MASTER-OAFA | C | 180 | 18.2 | 1609 | MASTER-OAFA | C | 180 | 18.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 40409 table
GRB_name GRB250509A
GCN_number 40409
Detection_method Fermi GBM Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 40409 SUBJECT: Fermi GRB 250509A: Global MASTER-Net observations report DATE: 25/05/09 23:31:05 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, G.Antipov, A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU), O.Gress, N.Budnev (ISU), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A.Sosnovskij (CrAO), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), D.Buckley (SAAO), R.Rebolo (The Instituto de Astrofisica de Canarias), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 250509A ( Fermi GBM team, GCN 40406) errorbox 7 sec after notice time and 64 sec after trigger time at 2025-05-09 22:34:33 UT, with upper limit up to 18.4 mag. Observations started at twilight. The observations began at zenith distance = 70 deg. The sun altitude is -9.7 deg. The galactic latitude b = -60 deg., longitude l = 237 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2866536 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 70 | 2025-05-09 22:34:33 | MASTER-OAFA | (03h 18m 00.28s , -38d 23m 19.1s) | C | 10 | 14.1 | 104 | 2025-05-09 22:35:03 | MASTER-OAFA | (03h 18m 00.24s , -38d 23m 19.1s) | C | 20 | 14.5 | 138 | 2025-05-09 22:35:42 | MASTER-OAFA | (03h 18m 00.14s , -38d 23m 18.9s) | C | 10 | 14.4 | 174 | 2025-05-09 22:36:18 | MASTER-OAFA | (03h 18m 00.11s , -38d 23m 18.5s) | C | 10 | 14.4 | 215 | 2025-05-09 22:36:53 | MASTER-OAFA | (03h 18m 00.10s , -38d 23m 18.6s) | C | 20 | 14.7 | 265 | 2025-05-09 22:37:39 | MASTER-OAFA | (03h 18m 00.12s , -38d 23m 19.3s) | C | 30 | 14.8 | 865 | 2025-05-09 22:46:44 | MASTER-OAFA | (03h 18m 00.32s , -38d 23m 28.0s) | C | 140 | 14.8 | 1041 | 2025-05-09 22:49:30 | MASTER-OAFA | (03h 18m 00.52s , -38d 23m 31.2s) | C | 160 | 16.3 | 1227 | 2025-05-09 22:52:36 | MASTER-OAFA | (03h 18m 00.73s , -38d 23m 34.3s) | C | 160 | 16.5 | 1414 | 2025-05-09 22:55:42 | MASTER-OAFA | (03h 18m 01.03s , -38d 23m 38.0s) | C | 160 | 17.0 | 1424 | 2025-05-09 22:55:43 | MASTER-OAFA | (03h 06m 24.43s , -38d 43m 44.4s) | C | 180 | 18.2 | 1600 | 2025-05-09 22:58:49 | MASTER-OAFA | (03h 18m 01.35s , -38d 23m 42.3s) | C | 160 | 17.1 | 1610 | 2025-05-09 22:58:49 | MASTER-OAFA | (03h 06m 24.67s , -38d 43m 47.0s) | C | 180 | 18.4 | 1786 | 2025-05-09 23:01:55 | MASTER-OAFA | (03h 18m 01.74s , -38d 23m 46.7s) | C | 160 | 17.1 | 1796 | 2025-05-09 23:01:55 | MASTER-OAFA | (03h 06m 24.96s , -38d 43m 50.0s) | C | 180 | 18.3 | 1972 | 2025-05-09 23:05:01 | MASTER-OAFA | (03h 18m 02.05s , -38d 23m 50.9s) | C | 160 | 17.1 | 1983 | 2025-05-09 23:05:02 | MASTER-OAFA | (03h 06m 25.27s , -38d 43m 53.2s) | C | 180 | 18.2 | 2159 | 2025-05-09 23:08:08 | MASTER-OAFA | (03h 18m 02.30s , -38d 23m 55.2s) | C | 160 | 17.1 | 2169 | 2025-05-09 23:08:08 | MASTER-OAFA | (03h 06m 25.58s , -38d 43m 56.5s) | C | 180 | 18.1 | 2356 | 2025-05-09 23:11:14 | MASTER-OAFA | (03h 06m 25.97s , -38d 44m 00.1s) | C | 180 | 18.0 | 2531 | 2025-05-09 23:14:20 | MASTER-OAFA | (03h 18m 02.98s , -38d 24m 03.8s) | C | 160 | 17.1 | 2542 | 2025-05-09 23:14:20 | MASTER-OAFA | (03h 06m 26.35s , -38d 44m 03.6s) | C | 180 | 18.0 | 2718 | 2025-05-09 23:17:26 | MASTER-OAFA | (03h 18m 03.37s , -38d 24m 09.0s) | C | 160 | 17.2 | 2728 | 2025-05-09 23:17:27 | MASTER-OAFA | (03h 06m 26.66s , -38d 44m 06.7s) | C | 180 | 18.0 | 2904 | 2025-05-09 23:20:33 | MASTER-OAFA | (03h 18m 03.73s , -38d 24m 14.1s) | C | 160 | 17.1 | 2914 | 2025-05-09 23:20:33 | MASTER-OAFA | (03h 06m 26.94s , -38d 44m 08.8s) | C | 180 | 17.6 | 3090 | 2025-05-09 23:23:39 | MASTER-OAFA | (03h 18m 04.07s , -38d 24m 19.9s) | C | 160 | 16.9 | 3100 | 2025-05-09 23:23:39 | MASTER-OAFA | (03h 06m 27.22s , -38d 44m 12.4s) | C | 180 | 17.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.
GCN 40410 table
GRB_name GRB250509A
GCN_number 40410
Detection_method Swift-XRT Other
ra 46.4496°
decl -38.8413°
Circular_text TITLE: GCN CIRCULAR NUMBER: 40410 SUBJECT: GRB 250509A: Prompt enhanced Swift-XRT position DATE: 25/05/09 23:32:52 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using 426 s of promptly downlinked XRT event data for GRB 250509A, we find an enhanced XRT position of the afterglow: RA, Dec: 46.44960, -38.84128 which is equivalent to: RA (J2000) = 03 05 47.90 Dec (J2000) = -38 50 28.6 with an uncertainty of 1.9 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/1311764. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team.
GCN 40411 table
GRB_name GRB250509A
GCN_number 40411
Detection_method Swift-XRT Det
ra 46.4496°
decl -38.8420°
Circular_text TITLE: GCN CIRCULAR NUMBER: 40411 SUBJECT: GRB 250509A: Enhanced Swift-XRT position DATE: 25/05/10 01:51:55 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 877 s of XRT Photon Counting mode data and 2 UVOT images for GRB 250509A, 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 = 46.44965, -38.84201 which is equivalent to: RA (J2000): 03h 05m 47.92s Dec (J2000): -38d 50' 31.2" with an uncertainty of 2.3 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 40422 table
GRB_name GRB250509A
GCN_number 40422
Detection_method Fermi GBM Det
t_trigger 22:33:29.290 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 40422 SUBJECT: GRB 250509A: Fermi GBM Observation DATE: 25/05/10 16:51:18 GMT FROM: Ava Myers at NASA GSFC A. Myers (NPP/GSFC), C. Meegan (UAH) and A. Holzmann Airasca (UniTrento and INFN Bari) report on behalf of the Fermi Gamma-ray Burst Monitor Team: "At 22:33:29.29 UT on 09 May 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250509A (trigger 768522814/250509940). which was also detected by Swift BAT (M. H. Siegel et al. 2025, GCN 40407). The Fermi GBM on-ground location is consistent with the Swift BAT position. The angle from the Fermi LAT boresight is 89 degrees. The GBM light curve consists of main emission episode with a duration (T90) of about 69 s (50-300 keV). The time-averaged spectrum from T0+0.000 to T0+69.120 s is best fit by a power law function. The power law index is -2.19 +/- 0.03. The event fluence (10-1000 keV) in this time interval is (6.18 +/- 0.29)E-06 erg/cm^2. The 1-sec peak photon flux measured starting from T0+6.2 s in the 10-1000 keV band is 3.6 +/- 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:
GCN 40456 table
GRB_name GRB250509A
GCN_number 40456
Detection_method Swift-BAT Det
ra 46.4510°
decl -38.8540°
Circular_text TITLE: GCN CIRCULAR NUMBER: 40456 SUBJECT: GRB 250509A: Swift-BAT refined analysis DATE: 25/05/14 02:57:21 GMT FROM: Rahul Gupta at NASA GSFC T. Parsotan (GSFC), S. D. Barthelmy (GSFC), R. Gupta (GSFC), H. A. Krimm (NSF), S. Laha (GSFC/UMBC), A. Y. Lien (U Tampa), C. B. Markwardt (GSFC), M. J. Moss (GSFC), D. M. Palmer (LANL), D. Sadaula (GSFC/UMBC), T. Sakamoto (AGU), M. H. Siegel (PSU) (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 250509A (trigger #1311764) (Siegel, et al., GCN Circ. 40407). The BAT ground-calculated position is RA, Dec = 46.451, -38.854 deg which is RA(J2000) = 03h 05m 48.3s Dec(J2000) = -38d 51' 15.1" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 96%. The mask-weighted BAT light curve shows a sharp rise and exponential decay profile. T90 (15-350 keV) is 55.43 +- 10.47 sec (estimated error including systematics). The time-averaged spectrum from T-2.85 to T+71.46 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.54 +- 0.08. The fluence in the 15-150 keV band is 2.4 +- 0.1 x 10^-06 erg/cm2. The 1-sec peak photon flux measured from T+0.42 sec in the 15-150 keV band is 1.9 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at https://swift.gsfc.nasa.gov/results/batgrbcat/BAT_refined_circular/1311764