[vsnet-grb-info 9798] GRB 100901A: optical observation in Maidanak, break confirmation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  11266
SUBJECT: GRB 100901A: optical observation in Maidanak, break confirmation
DATE:    10/09/10 01:48:03 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

A. Volnova (SAI MSU),  A. Pozanenko (IKI),  M. Ibrahimov (MAO), B. Hafizov 
(MAO), B. Satovski (Astrotel)  report on behalf of  larger GRB  follow-up 
collaboration:

We observed  the field of the Swift GRB 100901A (Immler  et al., GCN 11159) 
with AZT-22 telescope of Maidanak observatory starting  Sep. 7 (UT) 
20:32:06. We clearly detect the afterglow (Immler  et al., GCN 11159 and 
other follow-up ground based observations) in R-filter. The photometry of a 
stacked image is based on the same reference SDSS-DR7 stars used by our 
collaboration previously (GCNs 11191, 11200, 11255):

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

6.2977  R        4*300    22.05+/-0.09

The photometry above confirms suggested break (Kann et al, GCN 11246) in a 
light curve of the afterglow.