{
  "bibcode": "2022GCN.32889....1B",
  "body": "S. Belkin (IKI), N. Pankov (HSE),  V. Rumyantsev (CrAO), A. Pozanenko \n(IKI)  report on behalf of IKI GRB FuN:\n\nWe observed the GRB 221028A  (Lien et al., GCN 32874; Ursi et al., GCN \n32885) with ZTSh 2.6m telescope of CrAO observatory starting on Oct. 28 \n(UT) 19:38:37.  We do not detect any optical object within XRT \nlocalization (Lien et al., GCN 32874). This is consistent with reported \n  non-detections   (Hu et al., GCN 32878; Kumar et al., GCN 32876; \nLipunov et al., GCN 32879; Strausbaugh et al., GCN 32881; Niwano et al., \nGCN 32883; Kumar  et al., GCN 32886;  Watson   et al., GCN 32888).\n\nPreliminary photometry of the field in a combined image is following\n\nDate       UT start   t-T0    Filter Exp.     OT      err    UL(3sigma)\n                      (mid, days)       (s)\n2022-10-28 19:38:37   0.27233 R      10*120   n/d     n/d    20.7\n\nThe photometry is based on several nearby USNO-B1.0 (R2) stars\nUSNO-B1.0\nRA DEC R2\n20:56:40.7621 +41:04:57.000 15.60\n20:56:51.9768 +41:04:22.922 17.21\n20:57:00.0629 +41:02:55.072 16.04",
  "circularId": 32889,
  "createdOn": 1667073867000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "GRB 221028A: CrAO/ZTSh optical upper limit",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "GRB 221028A"
}