GRB 251130B
GCN Circular 42953
Subject
GRB 251130B: Glowbug gamma-ray detection
Date
2025-12-02T15:52:05Z (2 days ago)
From
C.C. Cheung at Naval Research Lab <Teddy.Cheung@nrl.navy.mil>
Via
Web form
C.C. Cheung, R. Woolf, M. Kerr, J.E. Grove (NRL), A. Goldstein (USRA), C.A. Wilson-Hodge, D. Kocevski (MSFC), and M.S. Briggs (UAH) report:
The Glowbug gamma-ray telescope [1,2,3], operating on the International Space Station, reports the detection of GRB 251130B, which was also detected by Fermi/GBM (GCN 42905, 42907) and AstroSat/CZTI (GCN 42925).
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2025-11-30 15:33:27.216 with a duration of 82.0 s and a total significance of about 31.8 sigma. The light curve comprises an initial broad peak at ~T0+1s, a narrow peak ~T0+19s, followed by a dominant peak at ~T0+70s. An excess at the Fermi/GBM trigger time (15:33:18) may be present in the Glowbug data at low significance.
The analysis results presented here are preliminary and use a response function that lacks a detailed characterization of the surrounding passive structure of the ISS.
Glowbug is a NASA-funded technology demonstrator for sensitive, low-cost gamma-ray transient telescopes developed, built, and operated by the U.S. Naval Research Laboratory (NRL) with support from the University of Alabama in Huntsville, USRA, and NASA MSFC. It was launched on 2023 March 15 aboard the Department of Defense Space Test Program’s STP-H9 to the ISS and operated until 2024 April when it was put in safe storage on orbit. Glowbug was removed from storage and resumed operation on 2025 September 12.
[1] Grove, J.E. et al. 2020, Proc. Yamada Conf. LXXI, arXiv:2009.11959
[2] Woolf, R.S. et al. 2022, Proc. SPIE, 12181, id. 121811O
[3] Woolf, R.S. et al. 2024, Proc. SPIE, 13151, id. 1315108
Distribution Statement A: Approved for public release. Distribution is unlimited.
GCN Circular 42925
Subject
GRB 251130B: AstroSat CZTI detection
Date
2025-12-01T18:20:31Z (3 days ago)
From
Anuraag Arya at IIT Bombay <aryaanuraag910@gmail.com>
Via
Web form
A. Goyal (IITB), A. Arya (IITB), M. Tembhurnikar (IUCAA), S. Salunke (IUCAA), Harsha K. H. (IUCAA), G. Waratkar (Caltech/IITB), A. Vibhute (IUCAA), V. Bhalerao (IITB), D. Bhattacharya (Ashoka University/IUCAA), A. R. Rao (IUCAA/TIFR), and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
Analysis of AstroSat CZTI data with the CIFT framework (Sharma et al., 2021, JApA, 42, 73) showed the detection of a long duration GRB 251130B which was also detected by Fermi GBM (Fermi GBM Team, GCN Circ. 42905).
The source was clearly detected in the CZT detectors in the 20-200 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2025-11-30T15:34:35 UTC. The measured peak count rate associated with the burst is 122 (+26, -28) counts/s above the background in the combined data of two quadrants (out of four), with a total of 467 (+165, -180) counts. The local mean background count rate was 139 (+3, -3) counts/s. Using cumulative rates, we measure a T90 of 11 (+5, -4) s.
The source was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range. The light curve showed multiple peaks of emission with the strongest peak at 2025-11-30T15:34:32 UTC. The measured peak count rate associated with the burst is 244 (+68, -42) counts/s above the background in the combined data of all quadrants, with a total of 1517 (+308, -325) counts. The local mean background count rate was 1246 (+7, -8) counts/s. We measure a T90 of 12 (+2, -3) s from the cumulative Veto light curve.
CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, URSC, IUCAA, SAC, and PRL. The Indian Space Research Organisation funded, managed, and facilitated the project.
CZTI GRB detections are reported regularly on the payload site at:
http://astrosat.iucaa.in/czti/?q=grb
GCN Circular 42912
Subject
Fermi GRB 251130B: Global MASTER-Net observations report
Date
2025-12-01T02:15:34Z (3 days ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
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-Kislovodsk robotic telescope [1] located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 251130B ( Fermi GBM team, GCN 42905) errorbox 31683 sec after notice time and 31712 sec after trigger time at 2025-12-01 00:21:50 UT, with upper limit up to 16.3 mag. The observations began at zenith distance = 79 deg. The sun altitude is -43.2 deg.
The galactic latitude b = -19 deg., longitude l = 255 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3056013
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
31742 | 2025-12-01 00:21:50 | MASTER-Kislovodsk | (06h 49m 44.31s , -34d 43m 17.4s) | C | 60 | 16.3 |
31742 | 2025-12-01 00:21:50 | MASTER-Kislovodsk | (06h 44m 55.88s , -34d 22m 49.2s) | C | 60 | 15.0 |
31822 | 2025-12-01 00:23:10 | MASTER-Kislovodsk | (07h 04m 25.10s , -34d 44m 07.1s) | C | 60 | 15.9 |
31822 | 2025-12-01 00:23:10 | MASTER-Kislovodsk | (06h 59m 36.92s , -34d 23m 35.3s) | C | 60 | 14.8 |
31902 | 2025-12-01 00:24:29 | MASTER-Kislovodsk | (06h 40m 40.37s , -32d 51m 33.0s) | C | 60 | 16.1 |
31902 | 2025-12-01 00:24:29 | MASTER-Kislovodsk | (06h 35m 57.97s , -32d 31m 06.6s) | C | 60 | 14.6 |
31982 | 2025-12-01 00:25:49 | MASTER-Kislovodsk | (07h 19m 00.02s , -34d 44m 45.6s) | C | 60 | 14.7 |
31982 | 2025-12-01 00:25:49 | MASTER-Kislovodsk | (07h 14m 12.41s , -34d 24m 10.5s) | C | 60 | 13.7 |
32061 | 2025-12-01 00:27:09 | MASTER-Kislovodsk | (06h 54m 58.67s , -32d 49m 48.0s) | C | 60 | 16.3 |
32061 | 2025-12-01 00:27:09 | MASTER-Kislovodsk | (06h 50m 16.82s , -32d 29m 18.5s) | C | 60 | 15.0 |
32141 | 2025-12-01 00:28:29 | MASTER-Kislovodsk | (07h 09m 15.84s , -32d 50m 53.6s) | C | 60 | 15.8 |
32141 | 2025-12-01 00:28:29 | MASTER-Kislovodsk | (07h 04m 33.40s , -32d 30m 27.1s) | C | 60 | 14.2 |
32221 | 2025-12-01 00:29:49 | MASTER-Kislovodsk | (07h 28m 45.67s , -34d 22m 42.6s) | C | 60 | 13.4 |
32381 | 2025-12-01 00:32:28 | MASTER-Kislovodsk | (06h 26m 31.94s , -32d 51m 09.2s) | C | 60 | 15.2 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
[1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp.
http : // www.pereplet.ru/lipunov/625.html
GCN Circular 42907
Subject
GRB 251130B: Fermi GBM Final Localization Correction
Date
2025-11-30T18:45:22Z (3 days ago)
Edited On
2025-12-02T18:18:47Z (2 days ago)
From
rhamburg@usra.edu
Edited By
Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov> on behalf of rhamburg@usra.edu
Via
Web form
The Fermi GBM team reports the detection of a likely LONG GRB
"At 15:33:18.11 UT on 30 November 2025, the Fermi Gamma-ray Burst Monitor (GBM)
triggered and located GRB 251130B (trigger 786209603/251130648).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 78.82, Dec = -43.31 (J2000 degrees, equivalent to J2000 5h 15m, –43d 18'), with a statistical uncertainty of 1.74 degrees.
The angle from the Fermi LAT boresight is 94 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251130648/quicklook/glg_skymap_all_bn251130648.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/bn251130648/quicklook/glg_healpix_all_bn251130648.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251130648/quicklook/glg_lc_medres34_bn251130648.gif"
GCN Circular 42905
Subject
GRB 251130B: Fermi GBM Final Real-time Localization
Date
2025-11-30T15:43:48Z (4 days ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely LONG GRB
At 15:33:18 UT on 30 Nov 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 251130B (trigger 786209603.108754 / 251130648).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 102.1, Dec = -45.5 (J2000 degrees, equivalent to J2000 06h 48m, -45d 30'), with a statistical uncertainty of 11.5 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/2025/bn251130648/quicklook/glg_skymap_all_bn251130648.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/bn251130648/quicklook/glg_healpix_all_bn251130648.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn251130648/quicklook/glg_lc_medres34_bn251130648.gif