[vsnet-grb-info 9209] GRB 100423A: CrAO optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10695
SUBJECT: GRB 100423A: CrAO optical observations
DATE:    10/04/27 09:52:28 GMT
FROM:    Alina Volnova at SAI MSU  <alinusss at gmail.com>

V. Rumyantsev, D. Shakhovskoy (CrAO), A. Volnova (SAI MSU), A.
Pozanenko (IKI)  report on behalf of larger GRB  follow-up
collaboration:

We observed the field of the Swift GRB 100423A (Stroh et al., GCN
10651) with AZT-11 telescope of CrAO Observatory between (UT) Apr. 23
18:15 - 18:46. We do not detect source at the position of the
afterglow (Filgas et al., GCN 10652; Ivarsen et al., GCN 10653).

The upper limit of the stacked image based on USNO-B1.0 star
1115-0180143  (RA(J2000) = 09 05 44.73  Dec(J2000)= +21 31 14.0) and
assuming R=17.21 is following:

T0+      Filter, Exposure, mag.
(mid, d)         (s)

0.7489   R       11x180    >20.7

The upper limit is compatible with power-law decay index -1.1 reported
by Ivarsen et al. (GCN 10653).