TITLE: GCN CIRCULAR NUMBER: 43418 SUBJECT: Fermi GRB 260115A: Global MASTER-Net observations report DATE: 26/01/15 18:45:39 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-Kislovodsk robotic telescope [1] located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 260115A ( Fermi GBM team, GCN 43417) errorbox 45 sec after notice time and 77 sec after trigger time at 2026-01-15 17:48:03 UT, with upper limit up to 18.5 mag. The observations began at zenith distance = 59 deg. The sun altitude is -41.0 deg. MASTER-Tunka robotic telescope located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 260115A errorbox 548 sec after notice time and 580 sec after trigger time at 2026-01-15 17:56:26 UT, with upper limit up to 19.5 mag. The observations began at zenith distance = 49 deg. The sun altitude is -59.1 deg. The galactic latitude b = 9 deg., longitude l = 214 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3103145 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 88 | 2026-01-15 17:48:03 | MASTER-Kislovodsk | (07h 36m 40.06s , +03d 42m 42.1s) | C | 20 | 17.2 | 113 | 2026-01-15 17:48:03 | MASTER-Kislovodsk | (07h 36m 40.06s , +03d 42m 42.1s) | C | 70 | 17.9 | Coadd 88 | 2026-01-15 17:48:03 | MASTER-Kislovodsk | (07h 40m 49.00s , +03d 19m 43.0s) | C | 20 | 17.3 | 128 | 2026-01-15 17:48:44 | MASTER-Kislovodsk | (07h 36m 40.13s , +03d 42m 39.9s) | C | 20 | 17.3 | 128 | 2026-01-15 17:48:44 | MASTER-Kislovodsk | (07h 40m 49.04s , +03d 19m 39.7s) | C | 20 | 17.3 | 174 | 2026-01-15 17:49:24 | MASTER-Kislovodsk | (07h 36m 40.22s , +03d 42m 38.6s) | C | 30 | 17.5 | 174 | 2026-01-15 17:49:24 | MASTER-Kislovodsk | (07h 40m 49.10s , +03d 19m 38.3s) | C | 30 | 17.6 | 229 | 2026-01-15 17:50:15 | MASTER-Kislovodsk | (07h 36m 40.26s , +03d 42m 37.7s) | C | 40 | 17.7 | 289 | 2026-01-15 17:50:15 | MASTER-Kislovodsk | (07h 36m 40.26s , +03d 42m 37.7s) | C | 160 | 18.5 | Coadd 295 | 2026-01-15 17:51:15 | MASTER-Kislovodsk | (07h 36m 40.31s , +03d 42m 37.5s) | C | 50 | 17.8 | 295 | 2026-01-15 17:51:15 | MASTER-Kislovodsk | (07h 40m 49.19s , +03d 19m 36.6s) | C | 50 | 18.0 | 385 | 2026-01-15 17:52:36 | MASTER-Kislovodsk | (07h 36m 40.38s , +03d 42m 37.5s) | C | 70 | 18.0 | 391 | 2026-01-15 17:52:42 | MASTER-Kislovodsk | (07h 40m 49.30s , +03d 19m 36.9s) | C | 70 | 18.2 | 611 | 2026-01-15 17:56:26 | MASTER-Tunka | (07h 20m 16.73s , +03d 41m 02.8s) | C | 60 | 19.5 | 611 | 2026-01-15 17:56:26 | MASTER-Tunka | (07h 19m 45.70s , +03d 47m 07.0s) | C | 60 | 19.2 | 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/43418. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...