TITLE: GCN CIRCULAR NUMBER: 43474 SUBJECT: Fermi trigger No 790570272: Global MASTER-Net observations report DATE: 26/01/20 17:15:40 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 [1] located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB260120.12 (trigger No 790570272,03h 14m 19.20s , -35d 09m 36.0s, R=1.41) errorbox 133 sec after notice time and 170 sec after trigger time at 2026-01-20 02:53:57 UT, with upper limit up to 20.9 mag. The observations began at zenith distance = 41 deg. The sun altitude is -32.2 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB260120.12 errorbox 50498 sec after notice time and 50534 sec after trigger time at 2026-01-20 16:53:22 UT, with upper limit up to 13.0 mag. The observations began at zenith distance = 78 deg. The sun altitude is -30.1 deg. The galactic latitude b = -58 deg., longitude l = 236 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3108498 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 185 | 2026-01-20 02:53:57 | MASTER-OAFA | (02h 59m 50.02s , -35d 32m 29.5s) | C | 30 | 18.5 | 226 | 2026-01-20 02:54:33 | MASTER-OAFA | (02h 59m 50.06s , -35d 32m 29.0s) | C | 40 | 20.7 | 277 | 2026-01-20 02:55:19 | MASTER-OAFA | (02h 59m 50.12s , -35d 32m 29.0s) | C | 50 | 20.8 | 338 | 2026-01-20 02:56:15 | MASTER-OAFA | (02h 59m 50.21s , -35d 32m 29.0s) | C | 60 | 20.9 | 50565 | 2026-01-20 16:53:22 | MASTER-Kislovodsk | (03h 10m 05.18s , -34d 42m 45.9s) | C | 60 | 13.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. [1] - V.M. Lipunov, V.G. Kornilov, E.S. Gorbovskoy, N.A. Tiurina & A.S.Kuznetsov, 2023, Astronomical Robotic Networks and Operative Multichanel Astrophysics, Lomonosov MSU PRESS, 591pp. http : // www.pereplet.ru/lipunov/625.html View this GCN Circular online at https://gcn.nasa.gov/circulars/43474. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...