[vsnet-grb-info 2861] GRB060204A: Swift/UVOT observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4698
SUBJECT: GRB060204A: Swift/UVOT observations
DATE:    06/02/06 22:26:26 GMT
FROM:    Antonino Cucchiara at PSU  <cucchiara at astro.psu.edu>

A. Cucchiara, D. Fox, S. Hunsberger, A. Retter, J. Nousek (PSU),
W. Voges (MPE), N. Gehrels (GSFC), on behalf of the Swift UVOT team.

The Swift/UVOT began observing the field of GRB 060204A,
detected by INTEGRAL (Mereghetti et al., GCN 4654)
at 00:17:07 UT on 2006-02-05, 10.8 hours after the trigger.
Within the XRT error circle reported by Morris et al. (GCN 4685) we found
a DSS/USNO catalogued object (USNO B1 0505-0367492,
B magnitude = 15.48). This is only 2 arcsecond from the XRT position.
A preliminary analysis of this known source shows a fading behaviour
followed by a rebrightening on a timescale of a day. For comparison, our B
magnitude at the beginning of the observation was 14.14 (+/- 0.03),
corrected for galactic extinction (E(B-V)=0.182)). At the moment, we cannot
infer whether this is the optical afterglow of this GRB or a kind of 
activity due to
the catalogued object. More XRT observations are ongoing to see if the 
XRT source
fades away.

Further analyses are forthcoming.