{
  "bibcode": "2021GCN.29512....1P",
  "body": "A. Pozanenko (IKI), S. Belkin (IKI), V. Kim (FAI, Pulkovo Observatory), \nY. Aimuratov (FAI), M. Krugov (FAI), N.Pankov (HSE)  report on behalf of \nGRB IKI FuN\n\nWe observed the optical transient of ZTF21aakruew/AT2021cwd (Yao et al., \nGCN 29508) which is probably an afterglow of GRB 210212B (Svinkin et \nal., GCN 29511) with AZT-20 telescope of Assy-Turgen observatory \nstarting on 2021-02-15 (UT) 17:33:23. The optical transient is \nmarginally detected in a stacked image in r'-filter.\n\nPreliminary photometry of the object  is following\nDate       UT start   t-T0    Filter  Exp.   OT    S/N  Err.  UL(3sigma)\n                             (mid, days)     (s)\n\n2021-02-15 17:33:23   3.64231  r'     59*60  23.8  2.5  0.5   23.6\n\nThe photometry is based on nearby SDSS-DR12 stars\nRA DEC r dr\n10:24:36.66048 +11:35:29.6088 18.206 0.008\n10:24:34.08528 +11:36:05.0220 17.486 0.006\n10:24:47.98080 +11:38:11.0832 15.153 0.003\n\nThe midtime value (t-T0) given in the table above  was counted from GRB \ntrigger of 2021-02-12 (UT) 02:37:57 (Svinkin et al., GCN 29511).\n\nThe power-law index  of the light curve (alpha ~ 1.7) is consistent with \nan afterglow after jet break. The light curve can be found in\n\nhttp://grb.rssi.ru/GRB210212B/GRB210212B_LC.png",
  "circularId": 29512,
  "createdOn": 1613483076000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "GRB 210212B (TF21aakruew/AT2021cwd): Assy optical observations",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "GRB 210212B"
}