GRB 260907A
GCN Circular 45530
Subject
GRB 260907A: Glowbug gamma-ray detection of a likely short burst
Date
2026-09-08T15:37:26Z (3 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 the likely short burst GRB 260907A, which was also detected by Fermi/GBM (GCN 45523).
Using an adaptive window with a resolution of 32-ms, the burst onset is determined to be 2026-09-07 00:28:00.800 with a duration of 0.26 s and a total significance of about 19.0 sigma. The light curve comprises a single peak.
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 45524
Subject
Fermi GRB 260907A: Global MASTER-Net observations report
Date
2026-09-07T04:31:48Z (5 days ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
M. Segura, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA)
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 (Lomonosov MSU)
D.Buckley (SAAO),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity)
A.Sosnovskij (CrAO RAS)
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory)
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)
R.Rebolo (The Instituto de Astrofisica de Canarias)
O.Gress, N.Budnev(ISU)
MASTER-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 260907A ( Fermi GBM team, GCN 45523) errorbox 11328 sec after notice time and 11363 sec after trigger time at 2026-09-07 03:37:25 UT, with upper limit up to 20.5 mag. The observations began at zenith distance = 42 deg. The sun altitude is -61.2 deg.
The galactic latitude b = -76 deg., longitude l = 270 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3499920
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
11394 | 2026-09-07 03:37:25 | MASTER-OAFA | (01h 31m 09.11s , -38d 48m 24.1s) | C | 60 | 20.1 |
11454 | 2026-09-07 03:37:25 | MASTER-OAFA | (01h 31m 09.11s , -38d 48m 24.1s) | C | 180 | 20.4 | Coadd
11470 | 2026-09-07 03:38:41 | MASTER-OAFA | (01h 41m 22.69s , -38d 46m 59.2s) | C | 60 | 15.4 |
11530 | 2026-09-07 03:38:41 | MASTER-OAFA | (01h 41m 22.69s , -38d 46m 59.2s) | C | 180 | 15.4 | Coadd
11546 | 2026-09-07 03:39:57 | MASTER-OAFA | (01h 41m 22.68s , -38d 48m 22.1s) | C | 60 | 15.4 |
11697 | 2026-09-07 03:42:28 | MASTER-OAFA | (01h 31m 04.23s , -38d 47m 29.4s) | C | 60 | 20.1 |
11773 | 2026-09-07 03:43:44 | MASTER-OAFA | (01h 41m 18.94s , -38d 46m 37.7s) | C | 60 | 15.4 |
11849 | 2026-09-07 03:45:00 | MASTER-OAFA | (01h 31m 09.75s , -38d 47m 24.5s) | C | 60 | 20.1 |
11926 | 2026-09-07 03:46:18 | MASTER-OAFA | (01h 11m 39.58s , -38d 47m 33.4s) | C | 60 | 20.2 |
11986 | 2026-09-07 03:46:18 | MASTER-OAFA | (01h 11m 39.58s , -38d 47m 33.3s) | C | 180 | 20.5 | Coadd
12004 | 2026-09-07 03:47:35 | MASTER-OAFA | (01h 11m 35.93s , -38d 46m 21.5s) | C | 60 | 20.1 |
12080 | 2026-09-07 03:48:51 | MASTER-OAFA | (01h 21m 52.14s , -38d 47m 58.8s) | C | 60 | 20.1 |
12140 | 2026-09-07 03:48:51 | MASTER-OAFA | (01h 21m 52.15s , -38d 47m 58.8s) | C | 180 | 20.5 | Coadd
12158 | 2026-09-07 03:50:09 | MASTER-OAFA | (01h 21m 55.65s , -38d 46m 20.8s) | C | 60 | 20.2 |
12235 | 2026-09-07 03:51:27 | MASTER-OAFA | (01h 11m 33.34s , -38d 46m 50.1s) | C | 60 | 20.1 |
12311 | 2026-09-07 03:52:43 | MASTER-OAFA | (01h 21m 48.50s , -38d 46m 00.2s) | C | 60 | 20.2 |
12387 | 2026-09-07 03:53:59 | MASTER-OAFA | (01h 11m 38.91s , -38d 46m 45.0s) | C | 60 | 20.1 |
12463 | 2026-09-07 03:55:15 | MASTER-OAFA | (01h 13m 40.50s , -40d 41m 32.2s) | C | 60 | 20.1 |
12523 | 2026-09-07 03:55:15 | MASTER-OAFA | (01h 13m 40.50s , -40d 41m 32.2s) | C | 180 | 20.5 | Coadd
12542 | 2026-09-07 03:56:33 | MASTER-OAFA | (01h 13m 36.54s , -40d 40m 02.2s) | C | 60 | 20.2 |
12618 | 2026-09-07 03:57:50 | MASTER-OAFA | (01h 24m 09.97s , -40d 41m 39.9s) | C | 60 | 20.2 |
12695 | 2026-09-07 03:59:06 | MASTER-OAFA | (01h 13m 39.46s , -40d 39m 55.7s) | C | 60 | 20.1 |
12771 | 2026-09-07 04:00:22 | MASTER-OAFA | (01h 13m 33.88s , -40d 40m 42.8s) | C | 60 | 20.1 |
12848 | 2026-09-07 04:01:39 | MASTER-OAFA | (01h 24m 06.29s , -40d 39m 53.0s) | C | 60 | 20.2 |
12925 | 2026-09-07 04:02:56 | MASTER-OAFA | (01h 13m 40.63s , -40d 40m 38.4s) | C | 60 | 20.1 |
13001 | 2026-09-07 04:04:13 | MASTER-OAFA | (01h 33m 43.67s , -40d 41m 37.4s) | C | 60 | 20.0 |
13061 | 2026-09-07 04:04:13 | MASTER-OAFA | (01h 33m 43.67s , -40d 41m 37.4s) | C | 180 | 20.2 | Coadd
13076 | 2026-09-07 04:05:27 | MASTER-OAFA | (01h 44m 13.62s , -40d 40m 12.2s) | C | 60 | 14.2 |
13136 | 2026-09-07 04:05:27 | MASTER-OAFA | (01h 44m 13.61s , -40d 40m 12.2s) | C | 180 | 14.2 | Coadd
13152 | 2026-09-07 04:06:43 | MASTER-OAFA | (01h 44m 13.63s , -40d 41m 56.9s) | C | 60 | 14.2 |
13226 | 2026-09-07 04:07:58 | MASTER-OAFA | (01h 44m 16.32s , -40d 40m 21.8s) | C | 60 | 14.2 |
13303 | 2026-09-07 04:09:15 | MASTER-OAFA | (01h 33m 37.50s , -40d 40m 48.5s) | C | 60 | 20.0 |
13380 | 2026-09-07 04:10:31 | MASTER-OAFA | (01h 44m 11.35s , -40d 39m 57.1s) | C | 60 | 14.2 |
13457 | 2026-09-07 04:11:49 | MASTER-OAFA | (01h 33m 43.62s , -40d 40m 43.8s) | C | 60 | 20.0 |
13534 | 2026-09-07 04:13:06 | MASTER-OAFA | (01h 28m 50.09s , -36d 52m 51.0s) | C | 60 | 18.5 |
13610 | 2026-09-07 04:14:22 | MASTER-OAFA | (01h 38m 48.29s , -36d 51m 36.8s) | C | 60 | 15.8 |
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 45523
Subject
GRB 260907A: Fermi GBM Final Real-time Localization
Date
2026-09-07T00:38:36Z (5 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 SHORT GRB
At 00:28:01 UT on 7 Sep 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260907A (trigger 810433686.93629 / 260907019).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 22.4, Dec = -39.0 (J2000 degrees, equivalent to J2000 01h 29m, -39d 00'), with a statistical uncertainty of 8.4 degrees.
The angle from the Fermi LAT boresight is 61.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260907019/quicklook/glg_skymap_all_bn260907019.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260907019/quicklook/glg_healpix_all_bn260907019.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260907019/quicklook/glg_lc_medres34_bn260907019.gif