{
  "circularId": 40769,
  "subject": "Swift GRB 250617B: Global MASTER-Net observations report",
  "bibcode": "2025GCN.40769....1L",
  "createdOn": 1750228615134,
  "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-OAFA robotic telescope  (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB 250617B ( K. L. Page et al., GCN 40760) errorbox  30652 sec after notice time and 30775 sec after trigger time at 2025-06-18 05:34:46 UT, with upper limit up to  18.6 mag. The observations began at zenith distance = 80 deg. The sun  altitude  is -74.8 deg. \n\nThe galactic latitude b = -19 deg., longitude l = 89 deg.\n\n\nReal time updated cover map and OT discovered available here: \nhttps://master.sai.msu.ru/site/master2/observ.php?id=2906362\n\nWe obtain a following upper limits.  \n\nTmid-T0  |          Site       |Filt.| Expt. | Limit| Comment\n_________|_____________________|_____|_______|______|________\n\n   30866 |         MASTER-OAFA |   C |   180 | 17.3 |        \n   31415 |         MASTER-OAFA |   C |    60 | 17.4 |        \n   31495 |         MASTER-OAFA |   C |    60 | 17.7 |        \n   32132 |         MASTER-OAFA |   C |   180 | 18.2 |        \n   32767 |         MASTER-OAFA |   C |    60 | 18.1 |        \n   32845 |         MASTER-OAFA |   C |    60 | 18.1 |        \n   33417 |         MASTER-OAFA |   C |   180 | 18.6 |        \nFilter C is a clear (unfiltred) band. \n\n\nThe observation and reduction will continue. \nThe message may be cited.\n",
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>",
  "submittedHow": "email",
  "eventId": "GRB 250617B"
}