GRB 260413A
GCN Circular 44291
Subject
Fermi GRB 260413A: Global MASTER-Net observations report
Date
2026-04-14T00:15:57Z (9 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-OAFA robotic telescope [1] located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 260413A ( Fermi GBM team, GCN 44289) errorbox 36329 sec after notice time and 36340 sec after trigger time at 2026-04-13 23:49:17 UT, with upper limit up to 20.7 mag. The observations began at zenith distance = 45 deg. The sun altitude is -20.6 deg.
The galactic latitude b = -31 deg., longitude l = 273 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3250278
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
36400 | 2026-04-13 23:49:17 | MASTER-OAFA | (05h 00m 14.08s , -47d 04m 31.9s) | C | 120 | 20.6 |
36536 | 2026-04-13 23:51:33 | MASTER-OAFA | (05h 00m 10.91s , -47d 02m 46.4s) | C | 120 | 20.7 |
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 44289
Subject
GRB 260413A: Fermi GBM Final Real-time Localization
Date
2026-04-13T13:54:18Z (10 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 13:43:37 UT on 13 Apr 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260413A (trigger 797780622.310696 / 260413572).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 87.0, Dec = -64.0 (J2000 degrees, equivalent to J2000 05h 47m, -64d 00'), with a statistical uncertainty of 26.0 degrees.
The angle from the Fermi LAT boresight is 15.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260413572/quicklook/glg_skymap_all_bn260413572.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/bn260413572/quicklook/glg_healpix_all_bn260413572.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260413572/quicklook/glg_lc_medres34_bn260413572.gif