[vsnet-grb-info 20109] GRB 171205A: TSHAO optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22205
SUBJECT: GRB 171205A: TSHAO optical observations
DATE:    17/12/07 19:30:56 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

A. Volnova (IKI), A. Pozanenko (IKI),  E. Mazaeva (IKI),  M. Krugov (FAPHI), 
I. Reva (FAPHI),  A. Kusakin (FAPHI),   report on behalf of  larger GRB 
follow-up collaboration:

We observed the field of GRB 171205A (D'Elia et al., GCN 22177)   with 
Zeiss-1000 1-m telescope of Tien Shan Astronomical Observatory starting on 
Dec. 06 (UT) 22:2319. We took several images in R-filter.  The afterglow of 
GRB 171205A (Izzo et al. GCN 22180; Emery et al. GCN 22181; Butler et al. 
GCN 22182; Mao et al. GCN 22186; Choi et al. GCN 22188; Melandri et al. GCN 
22189; Steeghs et al. GCN 22190; Cobb et al. GCN 22192; Volnova et al. GCN 
22193; Guidorzi et al. GCN 22197; Schmidl et al. GCN 22198; Lipunov et al. 
GCN 22199;  Ugarte Postigo et al. GCN 22204)  is marginally detected. 
Preliminary photometry is following.

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

2017-12-06  22:23:19 1.63574  R     1500    20.4  0.3


The photometry is based on several nearby USNO-B1.0 stars previously used in 
GCN 22193.