{
  "body": "V.Lipunov, E.Gorbovskoy, N.Tiurina,  P.Balanutsa, , D.Vlasenko, I.Panchenko,\nA.Kuznetsov,  G.Antipov,  A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin,\nV.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. 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-Kislovodsk robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 250331D ( Fermi GBM team, GCN 39961) errorbox  62486 sec after notice time and 62523 sec after trigger time at 2025-03-31 23:11:20 UT, with upper limit up to  17.9 mag. The observations began at zenith distance = 71 deg. The sun  altitude  is -35.8 deg. \n\nThe galactic latitude b = -7 deg., longitude l = 128 deg.\n\n\nReal time updated cover map and OT discovered available here: \nhttps://master.sai.msu.ru/site/master2/observ.php?id=2829033\n\nWe obtain a following upper limits.  \n\nTmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment\n_________|_____________________|_____________________|____________________________________|_____|_______|_______|________\n\n   62554 | 2025-03-31 23:11:20 |   MASTER-Kislovodsk | (02h 54m 34.96s , +65d 33m 33.8s) |   C |    60 | 17.7 |        \n   63431 | 2025-03-31 23:25:58 |   MASTER-Kislovodsk | (02h 54m 36.68s , +65d 33m 23.8s) |   C |    60 | 17.9 |        \n   64508 | 2025-03-31 23:43:54 |   MASTER-Kislovodsk | (02h 53m 45.13s , +65d 44m 21.5s) |   C |    60 | 17.7 |        \nFilter C is a clear (unfiltred) band. \n\n\nThe observation and reduction will continue. \nThe message may be cited.\n",
  "eventId": "GRB 250331D",
  "bibcode": "2025GCN.39990....1L",
  "circularId": 39990,
  "createdOn": 1743465785725,
  "submittedHow": "email",
  "subject": "Fermi GRB 250331D: Global MASTER-Net observations report",
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>"
}