GRB 260907B
GCN Circular 45528
Subject
Fermi GRB 260907B: Global MASTER-Net observations report
Date
2026-09-07T17:33:28Z (4 days ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
D.Buckley (SAAO),
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)
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)
M. Segura, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA)
MASTER-SAAO robotic telescope [1] located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 260907B ( Fermi GBM team, GCN 45525) errorbox 33321 sec after notice time and 33352 sec after trigger time at 2026-09-07 17:11:16 UT, with upper limit up to 17.0 mag. Observations started at twilight. The observations began at zenith distance = 77 deg. The sun altitude is -11.2 deg.
The galactic latitude b = -22 deg., longitude l = 79 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3500122
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
33383 | 2026-09-07 17:11:16 | MASTER-SAAO | (21h 29m 44.20s , +21d 44m 03.7s) | C | 60 | 16.4 |
33476 | 2026-09-07 17:12:49 | MASTER-SAAO | (21h 29m 50.74s , +21d 43m 05.9s) | C | 60 | 16.5 |
33570 | 2026-09-07 17:14:24 | MASTER-SAAO | (21h 38m 21.42s , +21d 41m 51.3s) | C | 60 | 16.3 |
33664 | 2026-09-07 17:15:57 | MASTER-SAAO | (21h 38m 27.60s , +21d 42m 08.7s) | C | 60 | 16.6 |
33761 | 2026-09-07 17:17:34 | MASTER-SAAO | (21h 29m 47.38s , +21d 42m 19.0s) | C | 60 | 17.0 |
33856 | 2026-09-07 17:19:09 | MASTER-SAAO | (21h 38m 27.46s , +21d 43m 52.6s) | C | 60 | 16.9 |
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 45525
Subject
GRB 260907B: Fermi GBM Final Real-time Localization
Date
2026-09-07T08:05:55Z (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 LONG GRB
At 07:55:23 UT on 7 Sep 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260907B (trigger 810460528.709988 / 260907330).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 327.5, Dec = 24.9 (J2000 degrees, equivalent to J2000 21h 49m, 24d 53'), with a statistical uncertainty of 5.8 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/2026/bn260907330/quicklook/glg_skymap_all_bn260907330.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/bn260907330/quicklook/glg_healpix_all_bn260907330.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260907330/quicklook/glg_lc_medres34_bn260907330.gif