TITLE: GCN CIRCULAR NUMBER: 44069 SUBJECT: EP260321a: Global MASTER-Net observations report DATE: 26/03/21 13:54:25 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-Tunka robotic telescope [1] located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the EP260321a ( EP Team et al., GCN 44068) errorbox 194 sec after notice time and 2105 sec after trigger time at 2026-03-21 13:05:23 UT, with upper limit up to 19.1 mag. Observations started at twilight. The observations began at zenith distance = 56 deg. The sun altitude is -16.9 deg. The galactic latitude b = 41 deg., longitude l = 239 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3200651 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 2135 | 2026-03-21 13:05:23 | MASTER-Tunka | (09h 57m 47.48s , +00d 56m 51.7s) | C | 60 | 18.8 | 2135 | 2026-03-21 13:05:23 | MASTER-Tunka | (09h 57m 34.12s , +01d 01m 05.4s) | C | 60 | 19.0 | 2208 | 2026-03-21 13:06:36 | MASTER-Tunka | (09h 57m 50.16s , +00d 58m 39.4s) | C | 60 | 18.8 | 2208 | 2026-03-21 13:06:36 | MASTER-Tunka | (09h 57m 36.78s , +01d 02m 53.3s) | C | 60 | 19.1 | 2283 | 2026-03-21 13:07:50 | MASTER-Tunka | (09h 57m 44.76s , +00d 57m 41.4s) | C | 60 | 18.9 | 2283 | 2026-03-21 13:07:50 | MASTER-Tunka | (09h 57m 31.35s , +01d 01m 55.6s) | C | 60 | 19.1 | 2354 | 2026-03-21 13:09:02 | MASTER-Tunka | (09h 57m 45.04s , +00d 58m 40.3s) | C | 60 | 18.8 | 2354 | 2026-03-21 13:09:02 | MASTER-Tunka | (09h 57m 31.61s , +01d 02m 54.6s) | C | 60 | 19.0 | 2429 | 2026-03-21 13:10:17 | MASTER-Tunka | (09h 57m 50.55s , +00d 57m 39.6s) | C | 60 | 18.8 | 2429 | 2026-03-21 13:10:17 | MASTER-Tunka | (09h 57m 37.10s , +01d 01m 53.7s) | C | 60 | 19.0 | 2502 | 2026-03-21 13:11:30 | MASTER-Tunka | (09h 57m 45.69s , +00d 56m 38.6s) | C | 60 | 18.9 | 2502 | 2026-03-21 13:11:30 | MASTER-Tunka | (09h 57m 32.22s , +01d 00m 52.6s) | C | 60 | 19.1 | 2575 | 2026-03-21 13:12:42 | MASTER-Tunka | (09h 57m 37.50s , +01d 01m 04.8s) | C | 60 | 19.1 | 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/44069. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...