TITLE:   GCN CIRCULAR
NUMBER:  11184
SUBJECT: GRB 100901A: ISON-NM optical observations
DATE:    10/09/02 20:41:25 GMT
FROM:    Leonid Elenin at ISON  <l.elenin@gmail.com>

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 100901A (Immler et al. GCN Circ.
11159)
with 0.45-m telescope of ISON-NM observatory on Sep. 02 (UT) 09:55:53 -
10:22:06.

The afterglow (Immler et al., GCN 11159; Guidorzi et al., GCN 11160; Ivanov
et al., GCN 11161;
Klunko et al., GCN 11162)  is well detected. For the preliminary photometry
of unfiltered image
we used USNO-B1.01127-0027229 field stars, assuming R=16.16:

T-T0      filter   exposure   mag.  mag. error
--------------------------------------------------------------

0.8561    W      20x60     17.82    +/- 0.03

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