[vsnet-grb-info 16559] GRB 150518A: Mondy optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17840
SUBJECT: GRB 150518A:  Mondy optical observations
DATE:    15/05/21 16:49:28 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

E. Mazaeva (IKI),  E. Klunko (ISTP), A. Volnova (IKI), I. Korobtsev 
(ISTP),  A. Pozanenko (IKI) report on behalf of larger GRB follow-up 
collaboration:

We observed the field of the MAXI/GSC GRB 150518A (Kawamuro, et al., GCN 
17825) with AZT-33IK telescope of Sayan observatory (Mondy) starting on 
May, 20 (UT) 16:50:47. We obtained several images in R-filter of 120 s 
exposure. The optical afterglow candidate (Xu et al., GCN 17829)  which 
coincides with SDSS J153648.25+161946.9 galaxy is clearly detected. 
Photometry of the galaxy is following

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

2015-05-20 16:50:47   1.81150  R        20*120  21.22 0.1

Photometry is based on SDSS DR9 stars:

SDSS9_id            R(Lupton)
J153646.11+161904.1    17.65
J153638.21+162002.8    18.41
J153637.55+162040.3    17.10
J153645.59+162055.5    16.35