[vsnet-grb-info 2542] GRB 051221B: BOOTES optical observations.

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4379
SUBJECT: GRB 051221B: BOOTES optical observations.
DATE:    05/12/22 01:36:01 GMT
FROM:    Javier Gorosabel at Danish Space Res Inst  <jgu at spacecenter.dk>

A. de Ugarte Postigo, M. Jelinek, S. Vitek, A.J. Castro-Tirado,
J. Gorosabel, S.B. Pandey, S. Guziy (IAA-CSIC, Granada), P. Kubanek and
R. Hudec (Astronomical Institute of the Academy of Sciences, Ondrejov),
report:

 "BOOTES-1 in South Spain (El Arenosillo, INTA, Huelva), responded under
 non-optimal conditions to GRB 051221 (Swift trigger 173904, Boyd et al.
 GCNC 4376). A sequence of RVI-band exposures started at 20:07:15 UT
 (235s after the GRB onset). Preliminary analysis does not reveal any
 transient optical source in the 3' radius SWIFT/BAT error box, and in
 particular at the position reported by SWIFT/XRT (Page et al.  GCNC
 4378). We set the following R-band upper limits:

  =============================================
   T-To (s)       Exp. Time    Lim. Mag. R-band
   Mid Exposure      (s)         (3 sigma)
  ---------------------------------------------
     235             5               14.5
     307             10              16.0
     353            6x10             16.5
     665         5x100+12x10         18.5
  =============================================

 We notice an important Galactic extinction in the GRB line of sight
 (E(B-V)=1.39,  Schlegel et al. 1998)"