TITLE: GCN CIRCULAR NUMBER: 43782 SUBJECT: IceCube Alert 260217A: Global MASTER-Net observations report DATE: 26/02/19 02:52:48 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) was pointed to the IceCube Alert 260217A (trigger No 80851825,05h 03m 33.60s , +14d 37m 48.0s, R=0.68) errorbox 16 sec after notice time and 1 days 73773 sec after trigger time at 2026-02-19 02:24:58 UT, with upper limit up to 20.1 mag. The observations began at zenith distance = 60 deg. The sun altitude is -35.3 deg. The galactic latitude b = -15 deg., longitude l = 187 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=3144643 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 160204 | 2026-02-19 02:24:58 | MASTER-OAFA | (05h 03m 45.23s , +14d 51m 29.0s) | C | 60 | 19.8 | 160264 | 2026-02-19 02:24:58 | MASTER-OAFA | (05h 03m 45.23s , +14d 51m 29.0s) | C | 180 | 20.1 | Coadd 160264 | 2026-02-19 02:24:58 | MASTER- | (05h 04m 46.08s , +13d 52m 00.1s) | C | 180 | 18.5 | 160264 | 2026-02-19 02:24:58 | MASTER- | (05h 03m 26.64s , +14d 25m 36.7s) | C | 180 | 17.8 | 160269 | 2026-02-19 02:26:03 | MASTER-OAFA | (05h 03m 45.21s , +14d 51m 29.3s) | C | 60 | 19.8 | 160335 | 2026-02-19 02:27:09 | MASTER-OAFA | (05h 03m 45.18s , +14d 51m 29.4s) | C | 60 | 19.8 | 160453 | 2026-02-19 02:28:07 | MASTER- | (05h 04m 43.62s , +13d 53m 35.3s) | C | 180 | 18.6 | 160453 | 2026-02-19 02:28:07 | MASTER- | (05h 03m 24.11s , +14d 27m 11.9s) | C | 180 | 17.9 | 160461 | 2026-02-19 02:28:15 | MASTER-OAFA | (05h 03m 45.15s , +14d 51m 29.9s) | C | 180 | 20.1 | Coadd 160641 | 2026-02-19 02:31:15 | MASTER- | (05h 04m 43.75s , +13d 51m 54.5s) | C | 180 | 18.5 | 160641 | 2026-02-19 02:31:15 | MASTER- | (05h 03m 24.24s , +14d 25m 30.5s) | C | 180 | 18.1 | 160830 | 2026-02-19 02:34:24 | MASTER- | (05h 04m 46.70s , +13d 53m 29.4s) | C | 180 | 18.4 | 160830 | 2026-02-19 02:34:24 | MASTER- | (05h 03m 27.15s , +14d 27m 05.6s) | C | 180 | 17.9 | 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/43782. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...