[vsnet-grb-info 9575] GRB 100728B: optical photometry of ISON-NM

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  11045
SUBJECT: GRB 100728B: optical photometry of ISON-NM 
DATE:    10/08/03 21:25:21 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

A. Volnova (SAI MASU), L. Elenin, I. Molotov (ISON), A. Pozanenko (IKI)
report on behalf of larger GRB  follow-up collaboration:

We observed the field of the Swift GRB 100728B (Morris et al. GCN  11009)
with 0.45-m telescope Ïf ISON-NM observatory  on  July 28 (Elenin at al.,
GCN 11012).

The afterglow ( Perley et al. GCN 11007; Morris et al. GCN 11009; Ivarsen et
al. GCN 11011)  is detectable on each of four images taken between July 28
(UT) 10:45:49 - 11:01:14.

A photometry of unfiltered images against SDSS field stars and R-mag 
obtained with Lupton transformations is following

t-t0,  filter, exposure,  OT
(sec)

 984   W     300            18.36+/-0.17
1294  W     300            18.93+/-0.22
1603  W     300            18.80+/-0.18
1909  W     300            19.00+/-0.30

Finding chart and SDSS calibration stars can be found at
http://grb.rssi.ru/GRB100728B/100728b-refstars.png