[vsnet-grb-info 14953] GRB 140423A: Mondy optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16247
SUBJECT: GRB 140423A: Mondy optical observations
DATE:    14/05/12 17:32:49 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

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

We observed the optical afterglow (Elenin et al., GCN 16143; Kaur et 
al., GCN 16144; Ferrante et al., GCN 16145; Chester et al., GCN 16147;
Maehara et al., GCN 16151) of the Swift GRB 140423A (Sonbas et al.,
GCN 16142) with AZT-33IK telescope of Sayan observatory (Mondy). We took 
several images in R-filter of 60 s exposure on Apr., 25 and
of 120 s exposure on Apr., 26 and 27.

The details of the photometry are the following:

date        UT start   t-T0       Filter  Exp.    OT
                       (mid, days)          (s)
2014-04-25  16:36:21  2.36772     R       90*60   22.63+/-0.10
2014-04-26  15:56:26  3.34068     R       46*120  23.46+/-0.18
2014-04-27  14:15:32  4.27964     R       54*120  > 22.9

The photometry is based on two SDSS stars, R (gri -> R transformations 
by Lupton 2005):

SDSS id                      R
J130911.04+494854.6   20.209+/-0.053
J130924.79+494946.6   19.533+/-0.038