[vsnet-grb-info 16469] GRB 150423A: TSHAO optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17750
SUBJECT: GRB 150423A: TSHAO optical observations
DATE:    15/04/24 14:37:06 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

E. Mazaeva (IKI), A. Volnova (IKI), A. Kusakin (Fesenkov Astrophysical 
Institute),  A. Pozanenko  (IKI) report on behalf of larger GRB follow-up 
collaboration:

We observed the field of GRB 150423A (Pagani et al., GCNC 17728) with 
Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory 
starting on Apr. 23 (UT) 17:43:02.  We obtained several  images in R-filter. 
In a combined image we marginally detect the source S2 and do not detect the 
afterglow (Varela et al., GCN 17729). Coordinates of the S2  (J2000) 14 46 
18.94  +12 17 04.4  with an uncertainty of  0.4" is marginally coincide with 
coordinates reported by Varela et al.  (GCN 17729).

A preliminary photometry is following

date              UT start    t-T0         Filter  Exp.        S1       S2 
S2_err
                                      (mid, days)        (s)

2015-04-23 17:43:02  0.57561  R       25*600  >22.7   22.7   0.3


and based on nearby SDSS DR9 stars:

 SDSS9_id R(Lupton)
 J144606.22+121513.3 15.42
 J144647.40+121502.9 17.54
 J144648.52+121523.3 15.15