{
  "createdOn": 1764544402682,
  "submittedHow": "email",
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>",
  "subject": "IceCube Alert 251130.75: Global MASTER-Net observations report",
  "circularId": 42910,
  "bibcode": "2025GCN.42910....1L",
  "body": "V.Lipunov, E.Gorbovskoy, A.Kuznetsov, K.Zhirkov, I.Panchenko, N.Tiurina, P.Balanutsa, V.Topolev, D.Vlasenko, \nG.Antipov,  A.Sankovich, Yu.Tselik, Ya.Kechin, V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU),\nO.Gress, N.Budnev (ISU),\nC.Francile,  F. Podesta, R.Podesta, E. Gonzalez  (Observatorio Astronomico Felix Aguilar (OAFA),\nA. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),\nA.Sosnovskij (CrAO),\nA. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity),\nD.Buckley (SAAO),\nR.Rebolo (The Instituto de Astrofisica de Canarias),\nL.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,\nA.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory) \n\nMASTER-Tunka robotic telescope  [1]  located in Russia (Applied Physics Institute, Irkutsk State University) was pointed to the IceCube Alert 251130.75 (trigger No 31953389,15h 18m 58.08s , -05d 39m 25.2s, R=0.95) errorbox  18825 sec after notice time and 18880 sec after trigger time at 2025-11-30 23:08:10 UT, with upper limit up to  15.1 mag. Observations started at twilight.  The observations began at zenith distance = 82 deg. The sun  altitude  is -14.8 deg. \n\nThe galactic latitude b = 41 deg., longitude l = 356 deg.\n\n\nReal time updated cover map and OT discovered available here: \nhttps://master.sai.msu.ru/site/master2/observ.php?id=3056129\n\nWe obtain a following upper limits.  \n\nTmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment\n_________|_____________________|_____________________|____________________________________|_____|_______|_______|________\n\n   18910 | 2025-11-30 23:08:10 |        MASTER-Tunka | (15h 18m 34.03s , -05d 47m 52.8s) |   C |    60 | 14.5 |        \n   18910 | 2025-11-30 23:08:10 |        MASTER-Tunka | (15h 18m 53.09s , -05d 55m 00.3s) |   C |    60 | 15.1 |        \n   18984 | 2025-11-30 23:09:24 |        MASTER-Tunka | (15h 18m 39.40s , -05d 48m 55.2s) |   C |    60 | 14.3 |        \n   18984 | 2025-11-30 23:09:24 |        MASTER-Tunka | (15h 18m 58.71s , -05d 56m 07.2s) |   C |    60 | 15.0 |        \nFilter C is a clear (unfiltred) band. \n\n\nThe observation and reduction will continue. \nThe message may be cited.\n\n[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.\nhttp : // www.pereplet.ru/lipunov/625.html\n"
}