TITLE: GCN CIRCULAR NUMBER: 40533 SUBJECT: Fermi GRB 250522B: Global MASTER-Net observations report DATE: 25/05/23 07:31:07 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> 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 250522B ( Fermi GBM team, GCN 40531) errorbox 27574 sec after notice time and 49860 sec after trigger time at 2025-05-23 06:59:53 UT, with upper limit up to 20.3 mag. The observations began at zenith distance = 29 deg. The sun altitude is -55.1 deg. The galactic latitude b = -24 deg., longitude l = 343 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2878662 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 49910 | 2025-05-23 06:59:53 | MASTER-OAFA | (19h 44m 22.76s , -56d 37m 08.7s) | C | 100 | 18.9 | 49920 | 2025-05-23 06:59:53 | MASTER-OAFA | (20h 00m 53.97s , -56d 11m 31.1s) | C | 120 | 20.2 | 50055 | 2025-05-23 07:02:17 | MASTER-OAFA | (19h 44m 22.46s , -56d 38m 27.6s) | C | 100 | 18.9 | 50065 | 2025-05-23 07:02:17 | MASTER-OAFA | (20h 00m 54.27s , -56d 12m 49.5s) | C | 120 | 20.2 | 50193 | 2025-05-23 07:04:35 | MASTER-OAFA | (19h 44m 26.76s , -56d 36m 55.4s) | C | 100 | 19.1 | 50203 | 2025-05-23 07:04:35 | MASTER-OAFA | (20h 00m 57.96s , -56d 11m 17.4s) | C | 120 | 20.3 | 50328 | 2025-05-23 07:06:51 | MASTER-OAFA | (19h 44m 20.88s , -56d 37m 43.4s) | C | 100 | 19.0 | 50339 | 2025-05-23 07:06:51 | MASTER-OAFA | (20h 00m 52.54s , -56d 12m 05.3s) | C | 120 | 20.2 | 50465 | 2025-05-23 07:09:07 | MASTER-OAFA | (19h 44m 22.05s , -56d 36m 37.8s) | C | 100 | 18.9 | 50475 | 2025-05-23 07:09:07 | MASTER-OAFA | (20h 00m 53.32s , -56d 11m 00.0s) | C | 120 | 20.2 | 50601 | 2025-05-23 07:11:23 | MASTER-OAFA | (19h 44m 26.58s , -56d 37m 34.2s) | C | 100 | 18.9 | 50611 | 2025-05-23 07:11:23 | MASTER-OAFA | (20h 00m 58.26s , -56d 11m 55.7s) | C | 120 | 20.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/40533. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...