[vsnet-grb-info 25483] GRB 200412B: Mondy optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  27583
SUBJECT: GRB 200412B: Mondy optical observations
DATE:    20/04/15 10:11:58 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

S. Belkin (IKI),  A. Pozanenko (IKI), E. Klunko (ISTP),  M. Eselevich
(ISTP), E. Mazaeva (IKI), A. Volnova (IKI) report on behalf of IKI-GRB FuN:

We observed the field of GRB 200412B (Fermi GBM team, GCN 27547; Mailyan
et al., GCN 27558; see also Burgess et al., GCN 27548; Longo et al., GCN
27557; Page et al., GCN 27561; Gupta et al., GCN 27563; Zheng et al., 
GCN 27565) with AZT-33IK 1.5-m telescope of Sayan observatory (Mondy) 
starting on 2020-04-14 (UT) 14:24:54.

We  clearly detected  the afterglow of GRB 200412B  (Lipunov et al., 
GCNs 27555, 27556; see also Kumar et al., GCN 27564; Belkin et al., GCN 
27566, Stecklum et al., GCN 27567, Moskvitin GCN 27570; Xin  et al., GCN 
27571).  Preliminary photometry of the afterglow is following.

Date       UT start  t-T0    Filter Exp.   OT    Err. UL
                     (mid, days)     (s)
2020-04-14 14:24:54  2.23002 R      15*120 21.22 0.08 22.8

The photometry is based on nearby USNO-B1.0 stars
UUSNO-B1.0_id R2
1525-0302108 17.21
1524-0300914 17.20
1525-0301929 17.85