{
  "bibcode": "2021GCN.30465....1V",
  "body": "A. Volnova (IKI), A. Moskvitin (SAO RAS),  A. Pozanenko (IKI), N. Pankov \n(IKI, HSE), S. Belkin (IKI, HSE)  report on behalf of GRB IKI FuN:\n\nWe observed GRB 210704A  (Ursi et al., GCN 30372; Berretta et al., GCN \n30375; Prasad et al., GCN 30378; D'Ai et al., GCN 30379; Malacaria et \nal., GCN 30380; Ridnaia et al., GCN 30388)  with Zeiss-1000 telescope of \nSAO RAS observatory on 2021-07-11 and  2021-07-13.    We marginally \ndetect the optical afterglow (Kim et al., GCN 30384; D'Avanzo et al., \nGCN 30385; Troja et al., GCN 30390; Kann et al., GCN 30391, 30401; Sun \net al., GCN 30411; D'Avanzo et al., GCN 30432; Rastinejad  et al., GCN \n30433;  Watson et al., GCN 30436; Pankov et al., GCN 30440; Troja et \nal., GCN 30442; Kann et al., GCN 30443; Fong et al., GCN 30445; O'Connor \net al., GCN  30451).\n\nPreliminary photometry of the afterglow is following\n\nDate       UT start   t-T0    Filter Exp.    OT      err   UL(3 sigma)\n                      (mid, days)       (s)\n\n2021-07-11 18:38:22   6.98262 R      12*300  23.1    0.3   23.2\n2021-07-13 18:16:08   8.94635 R      24*300  23.8   S/N=2  23.5\n\nThe photometry is based on nearby USNO_B-1.0 stars\nUSNO_B-1.0_id R2\n1471-0248922 16.31\n1471-0248878 17.04",
  "circularId": 30465,
  "createdOn": 1626530530000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "GRB 210704A: Zeiss-1000/SAO-RAS optical observations",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "GRB 210704A"
}