{
  "bibcode": "2020GCN.26965....1P",
  "body": "A. Pozanenko (IKI), S. Schmalz (KIAM),  V. Kim (AFIF, Pulkovo \nObservatory),  E. Mazaeva  (IKI), A. Volnova (IKI),  I. Molotov (KIAM) \nreport on behalf of larger GRB follow-up collaboration:\n\nWe observed the field of the  GRB 200131A   (Sbarufatti al., GCN  26953) \n  with  ORI-22 telescope of ISON-Castelgrande observatory starting on \nJan. 31  (UT) 23:11:28.  We obtained 120 images of 60 s exposure in \nClear filter.  The optical afterglow  (Sbarufatti al., GCN  26953; \nLipunov  al., GCN  26954; Butler al., GCN  26957; Strausbaugh al., GCN \n26959; Kuin al., GCN  26962)   is best detected in the stacked image of \nthe first 60 images.\nPreliminary photometry  of the  afterglow  is following\n\nDate       UT start   t-T0       Filter Exp.   OT   Err.\n                        (mid, days)        (s)\n\n2019-01-31 23:11:28   0.04353     Clear 60*60  18.35 0.25\n\nThe photometry is based on nearby USNO-B1.0  stars  (R2 magnitude).",
  "circularId": 26965,
  "createdOn": 1580679037000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "GRB 200131A: ISON-Castelgrande optical observations",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "GRB 200131A"
}