{
  "bibcode": "2020GCN.27604....1B",
  "body": "S. Belkin (IKI), A. Pozanenko (IKI), A.V. Shein (INASAN), I.A. Izvekova \n(ICAMER NASU),  E. Klunko (ISTP),  M. Eselevich (ISTP), R. Ya. \nInasaridze (AbAO), V.R. Ayvazian (AbAO),  G. V.  Kapanadze (AbAO), I. \nReva (FAPHI),  E. Mazaeva (IKI), A. Volnova  (IKI),  I. Molotov (KIAM) \nreport on behalf of  GRB IKI FuN:\n\nWe observed the field of GRB 200412B (Fermi GBM team, GCN 27547; Mailyan\net al., GCN 27558; see also Burgess et al., GCN 27548; Longo et al., GCN\n27557; Page et al., GCN 27561; Gupta et al., GCN 27563; Zheng et al., \nGCN 27565)  with Zeiss-2000 of Mt.Terskol observatory, Zeiss-1000 1-m \ntelescope of Tien Shan Astronomical Observatory,  AZT-33IK 1.5-m \ntelescope of Sayan observatory (Mondy) and AS-32 (0.7m) telescope of \nAbastumani Observatory.  We  still detected  the afterglow of GRB \n200412B  (Lipunov et al., GCNs 27555, 27556; see also e.g. Kumar et al., \nGCN 27564; Belkin et al., GCN 27566, Stecklum et al., GCN 27567,\nMoskvitin GCN 27570; Xin  et al., GCN 27571).  Preliminary photometry of \nthe afterglow is following.\n\nDate       UT start  t-T0       Filter  OT Err. UL   Observatory\n                     (mid, days)\n2020-04-13 23:10:27 1.59707 18*120 R 20.57 0.03 22.8 Terskol Z-2000\n2020-04-15 14:55:11 3.25105 15*120 V 21.95 0.14 22.8 Mondy AZT-33IK\n2020-04-16 17:04:23 4.33800 11*120 R n/d   n/d  20.5 Mondy AZT-33IK\n2020-04-16 22:30:40 4.57812 61*60  R n/d   n/d  22.2 AbAO AS-32\n2020-04-17 14:51:32 5.25754 28*120 R 23.22 0.28 23.4 Mondy AZT-33IK\n2020-04-17 19:53:06 5.47912 91*60  R n/d   n/d  22.3 TSHAO Z-1000\n2020-04-17 20:12:07 5.48573 36*120 R 23.29 0.29 23.4 Terskol Z-2000\n\nThe photometry is based on nearby USNO-B1.0 stars.\nThe light curve based on on above photometry  and photometry published \nearlier (Belkin  et al., GCN 27574;  Belkin  et al., GCN 27566;  Belkin \net al., GCN 27583) can be found at \nhttp://grb.rssi.ru/GRB200412B/GRB200412B_LC.png\n(For reference, we also posted the photometric results of the Tautenburg \nObservatory (Klose et al., GCN 27593; Stecklum et al., GCN 27582; Klose \net al., GCN 27575; Stecklum et al., GCN 27567).\n\nThe index of power law decay taken from our R-filter observations up to \n2.3 days is -1.58+/-0.07 (see also  Xin  et al. GCN 27571; Klose et al., \nGCN 27575). Later we may assume  a jet break previously suggested by \nKlose et al. (GCN 27575) and Stecklum et al. (GCN 27567).",
  "circularId": 27604,
  "createdOn": 1587228929000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "GRB 200412B: continued AbAO, Mondy, TSHAO, Terskol optical observations",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "GRB 200412B"
}