{
  "eventId": "GRB 251007B",
  "circularId": 42152,
  "subject": "Swift GRB 251007B: Global MASTER-Net observations report",
  "submittedHow": "email",
  "bibcode": "2025GCN.42152....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-SAAO robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 251007B ( A. Melandri et al., GCN 42147) errorbox  9413 sec after notice time and 9658 sec after trigger time at 2025-10-07 22:24:05 UT, with upper limit up to  17.1 mag. The observations began at zenith distance = 83 deg. The sun  altitude  is -52.3 deg. \n\nThe galactic latitude b = -5 deg., longitude l = 222 deg.\n\n\nReal time updated cover map and OT discovered available here: \nhttps://master.sai.msu.ru/site/master2/observ.php?id=3009588\n\nWe obtain a following upper limits.  \n\nTmid-T0  |          Site       |Filt.| Expt. | Limit| Comment\n_________|_____________________|_____|_______|______|________\n\n    9688 |         MASTER-SAAO |   C |    60 | 17.1 |        \nFilter C is a clear (unfiltred) band. \n\n\nThe observation and reduction will continue. \nThe message may be cited.\n",
  "createdOn": 1759876620627,
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>"
}