TITLE: GCN GRB OBSERVATION REPORT NUMBER: 3751 SUBJECT: GRB 050803: TAROT optical limits DATE: 05/08/03 22:36:47 GMT FROM: Alain Klotz at CESR-CNRS Klotz, A. (CESR-OMP), Boer M. (OHP-OAMP), Atteia J.L. (LATT-OMP) report: We imaged the field of GRB 050803 detected by SWIFT (trigger 148833) with the TAROT robotic telescope (D=25cm) located at the Calern observatory, France. Trigger occured at twilight and first image was acquired 60.9 min after the GRB. The field had an elevation of 5 degrees above horizon at the begining of the observations and then increased. We detected no new source comparing our unfiltered images with the DSS-2 ones. Following limits comes to co-additions of several sets of exposures. Tmid (min since GRB) Exp (s) R-Mag 60.9 - 63.4 90 >16.0 83.9 - 102.8 1080 >17.8 83.9 - 156.1 3600 >18.7 Limiting magnitude were estimated with the nearby USNO-B1 stars. This message can be cited.