[vsnet-grb-info 27064] GRB 201223A: Mondy and Kitab optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29167
SUBJECT: GRB 201223A: Mondy and Kitab optical observations
DATE:    20/12/24 13:09:08 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

S. Belkin (IKI),  A. Pozanenko (IKI), N. Pankov (HSE),  E. Klunko 
(ISTP), A. Novichonok (Petrozavodsk State University, KIAM), Sh. 
Ehgamberdiev (UBAI) report on behalf of IKI-GRB-FuN:

We observed the field of  GRB 201223A (Gropp et al., GCN 29158) with 
AZT-33IK telescope of Sayan observatory (Mondy) starting on Dec. 23 (UT) 
  18:29:01 and Kitab-ISON RC-36  telescope starting (UT) 19:25:57. The 
optical transient (Lipunov  et al. GCN 29157; Gropp et al., GCN 29158; 
Zhu et al. GCN 29159; Hu et al. GCN 29160; Hosokawa  et al. GCN 29164; 
Romanov et al. GCN 29165; Xin et al. GCN 29166) is detected in our 
stacked images in R-filter.

Preliminary photometry of the optical transient in a combined images is 
following

Date       UT start   t-T0    Filter Exp.    OT    Err.  UL(3sigma)
                       (mid, days)     (s)

2020-12-23 18:29:01   0.05943 R      10*120  18.95 0.23  19.5 AZT-33IK
2020-12-23 18:29:01   0.05943 R      55*120  19.38 0.09  22.1 AZT-33IK
2020-12-23 19:25:57   0.08161 R      60*60   19.40 0.20  19.6 RC-36

The photometry is based on the nearby USNO-B1.0 stars
USNO-B1.0_id R2
1611-0080890 18.64
1612-0081305 18.44