TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3754 SUBJECT: GRB 050803, optical observations DATE: 05/08/04 08:27:03 GMT FROM: Sylvio Klose at TLS Tautenburg S. Klose and C. Hoegner, Thueringer Landessternwarte Tautenburg, report: Tautenburg observed the error box of GRB 050803 (Band et al. 2005, GCN 3748; Racusin et al. 2005, GCN 3752) between 22:23 UT and 22:45 UT, i.e., about 3 hrs after the burst. Several images were taken, mostly in the I-band. Observations had to be finished after 22:45 UT because of bad weather. We do not detect the afterglow candidate reported by Berger et al. (2005, GCN 3753) down to about I=19.