TITLE: GCN CIRCULAR NUMBER: 40543 SUBJECT: Fermi trigger No 769611916: Global MASTER-Net observations report DATE: 25/05/23 20:31:00 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs 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-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB250522.55 (trigger No 769611916,00h 11m 31.92s , +62d 43m 01.2s, R=22.13) errorbox 14609 sec after notice time and 14646 sec after trigger time at 2025-05-22 17:09:17 UT, with upper limit up to 17.3 mag. The observations began at zenith distance = 76 deg. The sun altitude is -18.5 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB250522.55 errorbox 38205 sec after notice time and 38241 sec after trigger time at 2025-05-22 23:42:32 UT, with upper limit up to 19.4 mag. The observations began at zenith distance = 64 deg. The sun altitude is -17.1 deg. The galactic latitude b = 0 deg., longitude l = 119 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2878290 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 14649 | 2025-05-22 17:09:17 | MASTER-Tunka | (02h 05m 46.41s , +50d 25m 27.7s) | C | 6 | 15.6 | 14728 | 2025-05-22 17:10:35 | MASTER-Tunka | (00h 05m 25.37s , +43d 01m 08.1s) | C | 6 | 13.3 | 15462 | 2025-05-22 17:22:50 | MASTER-Tunka | (00h 13m 45.70s , +53d 52m 42.5s) | C | 6 | 16.3 | 16126 | 2025-05-22 17:33:54 | MASTER-Tunka | (00h 42m 26.97s , +70d 56m 56.4s) | C | 6 | 16.9 | 16151 | 2025-05-22 17:34:18 | MASTER-Tunka | (23h 20m 09.37s , +62d 13m 49.0s) | C | 6 | 16.7 | 16175 | 2025-05-22 17:34:42 | MASTER-Tunka | (22h 25m 24.81s , +52d 48m 43.4s) | C | 6 | 16.2 | 16669 | 2025-05-22 17:42:57 | MASTER-Tunka | (22h 55m 39.92s , +83d 36m 50.1s) | C | 6 | 17.2 | 16693 | 2025-05-22 17:43:21 | MASTER-Tunka | (22h 02m 28.60s , +71d 56m 01.9s) | C | 6 | 17.3 | 16718 | 2025-05-22 17:43:46 | MASTER-Tunka | (21h 26m 18.01s , +60d 32m 24.2s) | C | 6 | 17.3 | 21581 | 2025-05-22 19:04:06 | MASTER-Tunka | (00h 42m 07.07s , +41d 08m 07.5s) | C | 90 | 14.5 | 21581 | 2025-05-22 19:04:06 | MASTER- | (00h 41m 41.55s , +41d 04m 52.5s) | C | 90 | 14.4 | 38332 | 2025-05-22 23:42:32 | MASTER-Kislovodsk | (00h 41m 39.16s , +41d 22m 03.8s) | C | 180 | 19.0 | 38512 | 2025-05-22 23:42:32 | MASTER-Kislovodsk | (00h 41m 39.16s , +41d 22m 04.0s) | C | 540 | 19.4 | Coadd 38533 | 2025-05-22 23:45:53 | MASTER-Kislovodsk | (00h 41m 32.32s , +41d 21m 36.5s) | C | 180 | 18.8 | 38735 | 2025-05-22 23:49:16 | MASTER-Kislovodsk | (00h 41m 32.44s , +41d 22m 40.1s) | C | 180 | 18.8 | 112734 | 2025-05-23 20:23:35 | MASTER-Kislovodsk | (03h 02m 54.34s , +56d 12m 15.7s) | C | 60 | 17.1 | 112817 | 2025-05-23 20:24:58 | MASTER-Kislovodsk | (03h 17m 09.58s , +56d 11m 13.2s) | C | 60 | 17.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.