GCN Circular 2606
G.Bourban, 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 #3316 (~23% 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 2004 June 06 at 23:08:03 UT (9.84 h after the burst). We obtained 5 R-filtered images with exposure times of 180 and 480 s under non optimal wheather conditions and with a relatively high airmass (Fz ~2.5). 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.