GCN Circular 40409
Subject
Fermi GRB 250509A: Global MASTER-Net observations report
Date
2025-05-09T23:31:05Z (4 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 (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 250509A ( Fermi GBM team, GCN 40406) errorbox 7 sec after notice time and 64 sec after trigger time at 2025-05-09 22:34:33 UT, with upper limit up to 18.4 mag. Observations started at twilight. The observations began at zenith distance = 70 deg. The sun altitude is -9.7 deg.
The galactic latitude b = -60 deg., longitude l = 237 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2866536
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
70 | 2025-05-09 22:34:33 | MASTER-OAFA | (03h 18m 00.28s , -38d 23m 19.1s) | C | 10 | 14.1 |
104 | 2025-05-09 22:35:03 | MASTER-OAFA | (03h 18m 00.24s , -38d 23m 19.1s) | C | 20 | 14.5 |
138 | 2025-05-09 22:35:42 | MASTER-OAFA | (03h 18m 00.14s , -38d 23m 18.9s) | C | 10 | 14.4 |
174 | 2025-05-09 22:36:18 | MASTER-OAFA | (03h 18m 00.11s , -38d 23m 18.5s) | C | 10 | 14.4 |
215 | 2025-05-09 22:36:53 | MASTER-OAFA | (03h 18m 00.10s , -38d 23m 18.6s) | C | 20 | 14.7 |
265 | 2025-05-09 22:37:39 | MASTER-OAFA | (03h 18m 00.12s , -38d 23m 19.3s) | C | 30 | 14.8 |
865 | 2025-05-09 22:46:44 | MASTER-OAFA | (03h 18m 00.32s , -38d 23m 28.0s) | C | 140 | 14.8 |
1041 | 2025-05-09 22:49:30 | MASTER-OAFA | (03h 18m 00.52s , -38d 23m 31.2s) | C | 160 | 16.3 |
1227 | 2025-05-09 22:52:36 | MASTER-OAFA | (03h 18m 00.73s , -38d 23m 34.3s) | C | 160 | 16.5 |
1414 | 2025-05-09 22:55:42 | MASTER-OAFA | (03h 18m 01.03s , -38d 23m 38.0s) | C | 160 | 17.0 |
1424 | 2025-05-09 22:55:43 | MASTER-OAFA | (03h 06m 24.43s , -38d 43m 44.4s) | C | 180 | 18.2 |
1600 | 2025-05-09 22:58:49 | MASTER-OAFA | (03h 18m 01.35s , -38d 23m 42.3s) | C | 160 | 17.1 |
1610 | 2025-05-09 22:58:49 | MASTER-OAFA | (03h 06m 24.67s , -38d 43m 47.0s) | C | 180 | 18.4 |
1786 | 2025-05-09 23:01:55 | MASTER-OAFA | (03h 18m 01.74s , -38d 23m 46.7s) | C | 160 | 17.1 |
1796 | 2025-05-09 23:01:55 | MASTER-OAFA | (03h 06m 24.96s , -38d 43m 50.0s) | C | 180 | 18.3 |
1972 | 2025-05-09 23:05:01 | MASTER-OAFA | (03h 18m 02.05s , -38d 23m 50.9s) | C | 160 | 17.1 |
1983 | 2025-05-09 23:05:02 | MASTER-OAFA | (03h 06m 25.27s , -38d 43m 53.2s) | C | 180 | 18.2 |
2159 | 2025-05-09 23:08:08 | MASTER-OAFA | (03h 18m 02.30s , -38d 23m 55.2s) | C | 160 | 17.1 |
2169 | 2025-05-09 23:08:08 | MASTER-OAFA | (03h 06m 25.58s , -38d 43m 56.5s) | C | 180 | 18.1 |
2356 | 2025-05-09 23:11:14 | MASTER-OAFA | (03h 06m 25.97s , -38d 44m 00.1s) | C | 180 | 18.0 |
2531 | 2025-05-09 23:14:20 | MASTER-OAFA | (03h 18m 02.98s , -38d 24m 03.8s) | C | 160 | 17.1 |
2542 | 2025-05-09 23:14:20 | MASTER-OAFA | (03h 06m 26.35s , -38d 44m 03.6s) | C | 180 | 18.0 |
2718 | 2025-05-09 23:17:26 | MASTER-OAFA | (03h 18m 03.37s , -38d 24m 09.0s) | C | 160 | 17.2 |
2728 | 2025-05-09 23:17:27 | MASTER-OAFA | (03h 06m 26.66s , -38d 44m 06.7s) | C | 180 | 18.0 |
2904 | 2025-05-09 23:20:33 | MASTER-OAFA | (03h 18m 03.73s , -38d 24m 14.1s) | C | 160 | 17.1 |
2914 | 2025-05-09 23:20:33 | MASTER-OAFA | (03h 06m 26.94s , -38d 44m 08.8s) | C | 180 | 17.6 |
3090 | 2025-05-09 23:23:39 | MASTER-OAFA | (03h 18m 04.07s , -38d 24m 19.9s) | C | 160 | 16.9 |
3100 | 2025-05-09 23:23:39 | MASTER-OAFA | (03h 06m 27.22s , -38d 44m 12.4s) | C | 180 | 17.4 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.