GRB 260513A
GCN Circular 44602
Subject
Fermi GRB 260513A: Global MASTER-Net observations report
Date
2026-05-14T00:16:36Z (18 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-SAAO robotic telescope [1] located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 260513A ( Fermi GBM team, GCN 44599) errorbox 9005 sec after notice time and 9068 sec after trigger time at 2026-05-13 23:55:26 UT, with upper limit up to 20.0 mag. The observations began at zenith distance = 56 deg. The sun altitude is -67.4 deg.
The galactic latitude b = -46 deg., longitude l = 8 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3312539
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
9098 | 2026-05-13 23:55:26 | MASTER-SAAO | (21h 18m 43.70s , -36d 30m 06.5s) | C | 60 | 18.6 |
9158 | 2026-05-13 23:55:26 | MASTER-SAAO | (21h 18m 43.70s , -36d 30m 06.5s) | C | 180 | 19.3 |
9098 | 2026-05-13 23:55:26 | MASTER-SAAO | (21h 21m 03.32s , -36d 45m 45.9s) | C | 60 | 18.9 |
9158 | 2026-05-13 23:55:26 | MASTER-SAAO | (21h 21m 03.33s , -36d 45m 45.9s) | C | 180 | 19.6 |
9191 | 2026-05-13 23:56:59 | MASTER-SAAO | (21h 18m 50.50s , -36d 31m 06.3s) | C | 60 | 18.6 |
9191 | 2026-05-13 23:56:59 | MASTER-SAAO | (21h 21m 10.07s , -36d 46m 45.8s) | C | 60 | 18.9 |
9285 | 2026-05-13 23:58:34 | MASTER-SAAO | (21h 18m 44.23s , -36d 32m 06.3s) | C | 60 | 18.7 |
9285 | 2026-05-13 23:58:34 | MASTER-SAAO | (21h 21m 03.77s , -36d 47m 45.7s) | C | 60 | 18.9 |
9408 | 2026-05-14 00:00:06 | MASTER-SAAO | (21h 18m 50.60s , -36d 31m 55.6s) | C | 120 | 19.1 |
9558 | 2026-05-14 00:00:06 | MASTER-SAAO | (21h 18m 50.60s , -36d 31m 55.5s) | C | 420 | 19.8 |
9408 | 2026-05-14 00:00:06 | MASTER-SAAO | (21h 21m 10.09s , -36d 47m 34.6s) | C | 120 | 19.4 |
9558 | 2026-05-14 00:00:06 | MASTER-SAAO | (21h 21m 10.09s , -36d 47m 34.6s) | C | 420 | 20.0 |
9562 | 2026-05-14 00:02:40 | MASTER-SAAO | (21h 18m 46.82s , -36d 30m 36.0s) | C | 120 | 19.0 |
9562 | 2026-05-14 00:02:40 | MASTER-SAAO | (21h 21m 06.23s , -36d 46m 14.7s) | C | 120 | 19.2 |
9715 | 2026-05-14 00:05:13 | MASTER-SAAO | (21h 18m 46.52s , -36d 31m 51.3s) | C | 120 | 19.2 |
9715 | 2026-05-14 00:05:13 | MASTER-SAAO | (21h 21m 05.97s , -36d 47m 30.1s) | C | 120 | 19.4 |
9868 | 2026-05-14 00:07:46 | MASTER-SAAO | (21h 18m 49.92s , -36d 30m 29.6s) | C | 120 | 19.3 |
9868 | 2026-05-14 00:07:46 | MASTER-SAAO | (21h 21m 09.35s , -36d 46m 08.2s) | C | 120 | 19.5 |
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 44599
Subject
GRB 260513A: Fermi GBM Final Real-time Localization
Date
2026-05-13T21:34:57Z (18 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 21:24:18 UT on 13 May 2026, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 260513A (trigger 800400263.713514 / 260513892).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 320.8, Dec = -36.4 (J2000 degrees, equivalent to J2000 21h 23m, -36d 23'), with a statistical uncertainty of 2.3 degrees.
The angle from the Fermi LAT boresight is 65.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260513892/quicklook/glg_skymap_all_bn260513892.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/bn260513892/quicklook/glg_healpix_all_bn260513892.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2026/bn260513892/quicklook/glg_lc_medres34_bn260513892.gif