TITLE: GCN CIRCULAR NUMBER: 32425 SUBJECT: Fermi trigger No 680421061: Global MASTER-Net observations report DATE: 22/07/25 08:30:17 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) 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 GRB220725.24 (trigger No 680421061,16h 46m 26.40s , -42d 13m 12.0s, R=17.14) errorbox 445 sec after notice time and 486 sec after trigger time at 2022-07-25 05:59:02 UT, with upper limit up to 17.8 mag. The observations began at zenith distance = 68 deg. The sun altitude is -69.2 deg. The galactic latitude b = 1 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=2040348 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 516 | 2022-07-25 05:59:02 | MASTER-OAFA | (15h 30m 39.18s , -49d 38m 57.6s) | C | 60 | 16.7 | 607 | 2022-07-25 06:00:34 | MASTER-OAFA | (15h 39m 18.34s , -39d 51m 51.8s) | C | 60 | 17.5 | 845 | 2022-07-25 06:04:31 | MASTER-OAFA | (16h 06m 51.64s , -35d 55m 33.8s) | C | 60 | 17.8 | 937 | 2022-07-25 06:06:03 | MASTER-OAFA | (15h 55m 42.00s , -26d 34m 53.7s) | C | 60 | 17.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.