TITLE: GCN CIRCULAR NUMBER: 41148 SUBJECT: Swift GRB250725.08: Global MASTER-Net observations report DATE: 25/07/25 01:58:44 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) was pointed to the Swift GRB250725.08 (trigger No 1336720,02h 21m 32.40s , -82d 47m 02.4s, R=0.05) errorbox 23 sec after notice time and 45 sec after trigger time at 2025-07-25 01:52:22 UT, with upper limit up to 18.3 mag. The observations began at zenith distance = 64 deg. The sun altitude is -50.5 deg. MASTER-SAAO robotic telescope located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB250725.08 errorbox 30 sec after notice time and 53 sec after trigger time at 2025-07-25 01:52:29 UT, with upper limit up to 17.0 mag. The observations began at zenith distance = 53 deg. The sun altitude is -46.5 deg. The galactic latitude b = -34 deg., longitude l = 300 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2947351 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_____________________|_____|_______|______|________ 51 | MASTER-OAFA | C | 10 | 18.2 | 58 | MASTER-SAAO | P/ | 10 | 16.1 | 58 | MASTER-SAAO | P\\ | 10 | 16.5 | 67 | MASTER-OAFA | C | 10 | 18.3 | 92 | MASTER-SAAO | P/ | 20 | 16.8 | 92 | MASTER-SAAO | P\\ | 20 | 17.0 | 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/41148. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...