TITLE: GCN CIRCULAR NUMBER: 39838 SUBJECT: GRB 250322A: MASTER optical observation DATE: 25/03/22 18:47:54 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V.Lipunov, E.Gorbovskoy, A.Kuznetsov, G.Antipov,D.Vlasenko,K.Zhirkov, P.Balanutsa, N.Tyurina, Ya.Kechin, A.Chasovnikov, V.Topolev, V.Senik, K.Labzina (Lomonosov MSU), D.Buckley (SAAO), C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA), A.Sosnovskij (Crao RAS), O.Gress, N.Budnev, O.Ershova (ISU), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity), 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 (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South African Astronomical Observatory was pointed to the SWIFT (GCN 39835, Gupta et al.) GRB250322A (trigger No 1297832,07h 06m 56.00s , +07d 11m 56.0s, R=0.05) errorbox 4876 sec after notice time (5017 sec after trigger time) at 2025-03-22 17:29:49 UT,with upper limit up to 18.5 mag. Observations started at twilight. The observations began at zenith distance = 39 deg. The sun altitude is -9.8 deg. The galactic latitude b = 7 deg., longitude l = 209 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2820337 We obtain the following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment 5032 | MASTER-SAAO | C | 30 | 16.7 | 5077 | MASTER-SAAO | C | 120 | 17.4 | Coadd 5082 | MASTER-SAAO | C | 30 | 16.8 | 5146 | MASTER-SAAO | C | 60 | 16.9 | 5226 | MASTER-SAAO | C | 60 | 17.0 | 5320 | MASTER-SAAO | C | 90 | 17.0 | 5415 | MASTER-SAAO | C | 60 | 17.4 | 5494 | MASTER-SAAO | C | 60 | 17.4 | 5559 | MASTER-SAAO | C | 30 | 17.4 | 5604 | MASTER-SAAO | C | 120 | 18.2 | Coadd 5608 | MASTER-SAAO | C | 30 | 17.5 | 5672 | MASTER-SAAO | C | 60 | 17.6 | 5752 | MASTER-SAAO | C | 60 | 17.7 | 5812 | MASTER-SAAO | C | 180 | 18.3 | Coadd 5831 | MASTER-SAAO | C | 60 | 17.8 | 5910 | MASTER-SAAO | C | 60 | 17.8 | 6020 | MASTER-SAAO | C | 120 | 17.6 | 6129 | MASTER-SAAO | C | 60 | 17.8 | 6209 | MASTER-SAAO | C | 60 | 17.9 | 6289 | MASTER-SAAO | C | 60 | 17.9 | 6398 | MASTER-SAAO | C | 120 | 17.8 | 6537 | MASTER-SAAO | C | 120 | 17.8 | 6677 | MASTER-SAAO | C | 120 | 17.9 | 6816 | MASTER-SAAO | C | 120 | 17.9 | 6961 | MASTER-SAAO | C | 120 | 17.7 | 7036 | MASTER-SAAO | C | 270 | 18.1 | Coadd 7100 | MASTER-SAAO | C | 120 | 17.6 | 7194 | MASTER-SAAO | C | 30 | 17.8 | 7243 | MASTER-SAAO | C | 30 | 17.9 | 7273 | MASTER-SAAO | C | 90 | 18.5 | Coadd 7292 | MASTER-SAAO | C | 30 | 17.8 | 7342 | MASTER-SAAO | C | 30 | 17.8 | 7391 | MASTER-SAAO | C | 30 | 17.9 | 7421 | MASTER-SAAO | C | 90 | 18.4 | Coadd 7440 | MASTER-SAAO | C | 30 | 17.8 | 7490 | MASTER-SAAO | C | 30 | 17.8 | 7539 | MASTER-SAAO | C | 30 | 17.8 | 7569 | MASTER-SAAO | C | 90 | 18.5 | Coadd 7588 | MASTER-SAAO | C | 30 | 17.8 | 7637 | MASTER-SAAO | C | 30 | 17.9 | 7687 | MASTER-SAAO | C | 30 | 17.7 | 7736 | MASTER-SAAO | C | 30 | 17.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.