[vsnet-grb-info 12712] GRB 121212A: optical observations in ISON-NM observatory

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14071
SUBJECT: GRB 121212A: optical observations in ISON-NM observatory
DATE:    12/12/12 18:12:28 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

L. Elenin (KIAM),  A. Pozanenko (IKI), A. Volnova (SAI MSU, IKI), V. 
Savanevych (KNURE), A. Bryukhovetskiy (NSFCTC), I. Molotov (KIAM), report on 
behalf of  larger GRB  follow-up collaboration:

We observed the field of  the Swift GRB 121212A (Grupe et al., GCN   14064) 
with 0.45-m telescope of ISON-NM observatory  starting on  Dec. 12 (UT) 
06:58:31, i.e  138 s after burst trigger.  We took  several unfiltered 
images of 30 s exposures.  An automatic real-time pipeline did not detect 
any new object. However after stacking all images we marginally detected the 
source not visible in any filter of DSS2  in coordinates  11 51 10.40 +78 02 
15.3 with uncertainty of 0.3 arcsec in both coordinates. The source is 
consistent with enhanced XRT afterglow position    (Beardmore et al. GCN 
14066)  and optical transient (Kuin et al. GCN  14069;  Perley and Horesh 
GCN  14070) .   A  preliminary  photometry  of co-added frames is based  on 
the USNO-B1.0 (R2)  nearby  stars is following:

UT start,      Exposure,  OT,              UL (3 sigma)

06:58:31         30       n/d                 18.3
06:58:31       3x30       n/d                 18.7
06:58:31      10x30       n/d                 19.4
06:58:31      40x30       20.7 +/- 0.4        20.5