[vsnet-grb-info 2064] GRB 050827 : OSN 1.5m optical observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3903
SUBJECT: GRB 050827 : OSN 1.5m optical observations
DATE:    05/08/29 17:52:41 GMT
FROM:    Sergei Guziy at IAA  <gss at iaa.es>

S. Guziy, J. Gorosabel, A.J. Castro-Tirado, V. Casanova, 
A. de Ugarte Postigo, M. Jelinek, (IAA-CSIC) report:

 "We have acquired R and I-band images of the GRB 050827 
 XRT error box (Capalbi et al. GCN Circ. 3899) with the OSN
 1.5m telescope. We detect two objects consistent with the 
 8" radius XRT error circle. The coordinates of the two 
 objects are:

  Source 1:
     RA(J2000) =  04:17:08.9
     DEC(J2000)= +18:11:57.0

  Source 2:
     RA(J2000) =  04:17:09.6
     DEC(J2000)= +18:12:02.0

 with a conservative astrometric error of 1.5".

 Based on the USNO catalog we estimate magnitudes of 
 R=23.7 ± 0.37 and R=23.4 ± 0.26 for S1 and S2, 
 respectively. A finding chart can be found at:

 http://www.dsri.dk/~jgu/grb050827/FCs/osn.R.gif

 Further observations are encouraged to check the 
 reliability/variability of the two optical sources.

 We thank Julius Halpern for making us available his
 1.3m MDM telescope images."

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