{
  "circularId": 33728,
  "bibcode": "2023GCN.33728....1L",
  "body": "\nV.Lipunov, P.Balanutsa, A.Kuznetsov, N.Tiurina, O.Gress, E.Gorbovskoy, G.Antipov,K.Zhirkov, D.Vlasenko,\nYa.Kechin, A.Chasovnikov,V.Senik, V.Topolev, Yu.Tselik, Siyu Wu, V.Vladimirov, D.Cheryasov (Lomonosov Moscow State University, SAI,Physics Department),\nC.Francile, F. Podesta, C.Lopez, R. Podesta (Observatorio Astronomico Felix Aguilar OAFA),\nD.A.H.Buckley (SAAO),\nR. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias),\nL.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.Corella,L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory),\nN.M.Budnev, O.Ershova (ISU,API),\nA. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),\nA. Gabovich, V.Yurkov (Blagoveschensk Educational State University),\nK.Vetrov, V.Shumkov, T.Pogrosheva, E.Minkina, O.Ershova (Lomonosov MSU)\n\nMASTER-Amur robotic telescope  (Global MASTER-Net http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)  located in Russia (Blagoveshchensk State Pedagogical University) was pointed to the SWIFT GRB230506.53 (trigger No 1167266,21h 47m 54.90s , +44d 30m 39.9s, R=0.1) errorbox  6276 sec after trigger time at 2023-05-06 14:29:54 UT, so as alert didn't come from GCN socket system.\n\nThe observations began at zenith distance = 72 deg. The sun  altitude  is -22.3 deg.The galactic latitude b = -7 deg., longitude l = 92 deg.\n\n\nReal time updated cover map and OT discovered available here:\nhttps://master.sai.msu.ru/site/master2/observ.php?id=2214809\n\nWe obtained following upper limits.\n\nTmid-T0  |          Site       |Filt.| Expt. | Limit| Comment\n_________|_____________________|_____|_______|______|________\n\n    6367 |         MASTER-Amur |   C |   180 | 16.8 |\n    6567 |         MASTER-Amur |   C |   180 | 17.2 |\n    6767 |         MASTER-Amur |   C |   180 | 17.3 |\n    7037 |         MASTER-Amur |   C |   720 | 18.0 |  Coadd\n    6966 |         MASTER-Amur |   C |   180 | 17.3 |\n    7166 |         MASTER-Amur |   C |   180 | 17.4 |\n    7366 |         MASTER-Amur |   C |   180 | 17.4 |\nFilter C is a clear (unfiltred) band.\n\nObservations and analysis will be  continued.\nThe message may be cited.\n\n",
  "createdOn": 1683386879834,
  "eventId": "GRB 230506B",
  "subject": "GRB 230506B: MASTER optical observations",
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>"
}