[vsnet-grb-info 7114] GRB081203A: BTA observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8695
SUBJECT: GRB081203A: BTA observation
DATE:    08/12/22 12:38:47 GMT
FROM:    Vladimir Sokolov at SAO RAS  <sokolov at sao.ru>

T. Fatkhullin, A. Moskvitin (SAO RAS, Russia), A. Posanenko (IKI RAS, 
Russia), E. Sonbas (SAO RAS,University of Cukurova, Turkey ),
A. Volnova (SAI MSU), V. Rumyantsev (CrAO), V. Kouprianov (GAO RAS),
V. Sokolov (SAO RAS) and A.J. Castro-Tirado ((IAA-CSIC Granada, Spain)
on behalf of a larger collaboration report:

We observed the field of the GRB081203A (A. M. Parsons et al., GCN #8595) 
in the Rc-band with the 6-m telescope of the SAO RAS in Caucasus. In total 15
3-min exposures were obtained starting from 01:42 7 Dec. 2008 UT (T-T_0 =
3.49 days).  We clearly detected an object at the position of the UVOT
optical transient (M. De Pasquale and A. Parsons, GCN #8603).
Calibration based on the SDSS stars yields the brightness of the OT as
R = 23.94 +/- 0.13 (errors are statistical only). At the 3.2 +/- 0.2 
arcsec to the South-West from the OT position we also detect an extended
object with R = 22.74 +/- 0.07. For redshift of z=2.05 (N.P.M Kuin et al,
astro-ph/0812.2943) it corresponds to ~26 kpc in projection (H0=71,
Omega_M=0.3, Omega_L=0.7). It is unlikely that this object is a host 
galaxy of the GRB081203A but redshift measurements are needed for certainty. 
Further observations are planned.

Our finding chart can be dowloaded from
ftp://ftp.sao.ru/pub/grb/GRB081203A/GRB081203A_OT.jpg

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