{
  "circularId": 39424,
  "submitter": "Alexei Pozanenko at IKI, Moscow <grb.alex@gmail.com>",
  "subject": "GRB 250221A: Mondy optical observations",
  "body": "N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunlo (ISTP), A. Volnova\n(IKI) report on behalf of IKI GRB FuN:\n\nWe observed the optical afterglow (Francile et al., GCN 39395; Watson et\nal., GCN 39397; Melandri et al., GCN 39406; Shilling et al., GCN 39409; Guo\net al., GCN 39412; Muenter et al., GCN 39417; Palmerio et al., GCN 39418;\nPankov et al., GCN 39422) of the Swift GRB 250221A (Caputo et al., GCN\n39396) with AZT-33IK telescope of Mondy observatory starting on 2025-02-21\n(UT) 12:25:52 in R filter.\n\nThe afterglow is clearly detected. Preliminary photometry of the afterglow\nin the stacked image is the following\n\nDate UT start t-T0 Exp. Filter OT Err. UL(3sigma)\n\n2025-02-21 12:25:52 0.38490 23x60 R 20.30 0.05 22.5\n\nThe photometry is based on nearby USNO-B1.0 (R2) stars.\n",
  "createdOn": 1740227153991,
  "bibcode": "2025GCN.39424....1P",
  "eventId": "GRB 250221A",
  "submittedHow": "email"
}