TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3015
SUBJECT: GRB 050209 Optical observations
DATE:    05/02/09 11:44:42 GMT
FROM:    Gerald Bourban at Geneva Observatory  <grb@obs.unige.ch>

G.Bourban, C.Vuissoz, F.Carrier, G.Burki and L.Weber (Geneva 
Observatory, Switzerland) report:


We have carried out optical observations of the 12'x 12' field centered 
on the error circle of HETE trigger #11568 (~93% of the whole 
uncertainty area provided by HETE/WXM) using the C2 CCD Camera mounted 
on the Swiss 1.2-meter telescope located at the ESO La Silla Observatory 
(Chile). The observations began on 2005 Feb 09 at 03:57:30 UT (129s 
after the alert sent by HETE team, i.e 2.43 h after the burst) and four 
different sets of measurements were performed during the night at 03:57 
UT, 04:57 UT, 06:07 UT and 07:12 UT (1.5 < Fz < 2.7). A total of 3 
R-filtered images with exposure time of 180s as well as 8 R-filtered 
480s exposures were obtained under good wheather conditions.

The division of these images as well as their comparison with the 
USNO-A2 catalog did not reveal any new or fainting source inside the 
field of view of the C2 camera, down to a limiting magnitude of R < 20.5.

This message may be cited.