GCN Circular 44218
Subject
Fermi trigger No 797039833: Global MASTER-Net observations report
Date
2026-04-05T11:00:42Z (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 GRB260404.99 (trigger No 797039833,12h 09m 43.20s , -35d 10m 48.0s, R=16.55) errorbox 21767 sec after notice time and 21798 sec after trigger time at 2026-04-05 06:00:27 UT, with upper limit up to 19.5 mag. The observations began at zenith distance = 19 deg. The sun altitude is -58.3 deg.
The galactic latitude b = 27 deg., longitude l = 294 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=3232826
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
21859 | 2026-04-05 06:00:27 | MASTER-OAFA | (12h 59m 32.15s , -41d 01m 29.5s) | C | 120 | 18.4 |
23083 | 2026-04-05 06:21:21 | MASTER-OAFA | (12h 37m 40.74s , -42d 05m 50.7s) | C | 60 | 17.6 |
23143 | 2026-04-05 06:21:21 | MASTER-OAFA | (12h 37m 40.75s , -42d 05m 50.7s) | C | 180 | 18.7 | Coadd
23163 | 2026-04-05 06:22:42 | MASTER-OAFA | (12h 48m 26.86s , -42d 07m 29.9s) | C | 60 | 17.5 |
23240 | 2026-04-05 06:23:58 | MASTER-OAFA | (12h 37m 42.77s , -42d 05m 40.4s) | C | 60 | 18.3 |
23334 | 2026-04-05 06:25:32 | MASTER-OAFA | (12h 48m 27.14s , -42d 06m 12.0s) | C | 60 | 19.2 |
23409 | 2026-04-05 06:26:48 | MASTER-OAFA | (12h 37m 39.06s , -42d 07m 24.1s) | C | 60 | 19.1 |
23525 | 2026-04-05 06:28:43 | MASTER-OAFA | (12h 35m 41.78s , -40d 12m 31.0s) | C | 60 | 18.5 |
23585 | 2026-04-05 06:28:43 | MASTER-OAFA | (12h 35m 41.77s , -40d 12m 31.0s) | C | 180 | 19.5 | Coadd
23600 | 2026-04-05 06:29:59 | MASTER-OAFA | (12h 46m 10.91s , -40d 11m 40.1s) | C | 60 | 19.2 |
23676 | 2026-04-05 06:31:14 | MASTER-OAFA | (12h 35m 48.78s , -40d 12m 30.1s) | C | 60 | 19.2 |
23761 | 2026-04-05 06:32:39 | MASTER-OAFA | (12h 46m 18.29s , -40d 12m 02.0s) | C | 60 | 19.1 |
23837 | 2026-04-05 06:33:55 | MASTER-OAFA | (12h 35m 41.12s , -40d 12m 28.9s) | C | 60 | 19.1 |
23932 | 2026-04-05 06:35:30 | MASTER-OAFA | (12h 49m 34.20s , -47d 48m 23.1s) | C | 60 | 19.1 |
24013 | 2026-04-05 06:36:51 | MASTER-OAFA | (13h 01m 25.31s , -47d 50m 17.4s) | C | 60 | 19.1 |
24089 | 2026-04-05 06:38:07 | MASTER-OAFA | (12h 49m 34.19s , -47d 49m 47.0s) | C | 60 | 19.1 |
35699 | 2026-04-05 09:51:38 | MASTER-OAFA | (12h 18m 08.46s , -19d 48m 02.5s) | C | 60 | 16.7 |
35759 | 2026-04-05 09:51:38 | MASTER-OAFA | (12h 18m 08.45s , -19d 48m 02.5s) | C | 180 | 17.1 | Coadd
35765 | 2026-04-05 09:52:43 | MASTER-OAFA | (12h 18m 08.49s , -19d 48m 02.4s) | C | 60 | 16.6 |
35830 | 2026-04-05 09:53:49 | MASTER-OAFA | (12h 18m 08.48s , -19d 48m 02.4s) | C | 60 | 16.5 |
35896 | 2026-04-05 09:54:55 | MASTER-OAFA | (12h 18m 08.55s , -19d 48m 02.6s) | C | 60 | 16.5 |
35956 | 2026-04-05 09:54:55 | MASTER-OAFA | (12h 18m 08.55s , -19d 48m 02.7s) | C | 180 | 16.6 | Coadd
35962 | 2026-04-05 09:56:00 | MASTER-OAFA | (12h 18m 08.56s , -19d 48m 02.5s) | C | 60 | 16.4 |
36028 | 2026-04-05 09:57:06 | MASTER-OAFA | (12h 18m 08.63s , -19d 48m 02.7s) | C | 60 | 16.2 |
36095 | 2026-04-05 09:58:13 | MASTER-OAFA | (12h 18m 08.72s , -19d 48m 03.5s) | C | 60 | 16.0 |
36155 | 2026-04-05 09:58:13 | MASTER-OAFA | (12h 18m 08.72s , -19d 48m 03.6s) | C | 180 | 16.3 | Coadd
36160 | 2026-04-05 09:59:18 | MASTER-OAFA | (12h 18m 08.73s , -19d 48m 03.4s) | C | 60 | 16.0 |
36225 | 2026-04-05 10:00:24 | MASTER-OAFA | (12h 18m 08.80s , -19d 48m 03.7s) | C | 60 | 15.8 |
36291 | 2026-04-05 10:01:30 | MASTER-OAFA | (12h 18m 08.89s , -19d 48m 03.9s) | C | 60 | 15.7 |
36357 | 2026-04-05 10:02:35 | MASTER-OAFA | (12h 18m 08.96s , -19d 48m 04.3s) | C | 60 | 15.5 |
36423 | 2026-04-05 10:03:41 | MASTER-OAFA | (12h 18m 09.09s , -19d 48m 04.8s) | C | 60 | 15.3 |
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