TITLE: GCN CIRCULAR NUMBER: 7793 SUBJECT: GRB080603: Super-LOTIS detection of Optical Counterpart DATE: 08/06/03 19:58:42 GMT FROM: Peter A. Milne at Super-LOTIS P.A. Milne (U Arizona) and A. Updike (Clemson U) report on behalf of the Super-LOTIS team: The 0.6m Super-LOTIS telescope began R-band observations of the error region of GRB080603 at 11:19:04 UT. The OT detected by Gomboc et al. (GCN 7788) and Chornock et al. (GCN 7789) is not apparent in the initial images, but is clearly visible in subsequent images. Using a stack of 10 x 60sec images obtained between 11:22:44 -> 11:33:46, we estimate the magnitude of the source to be R=19.3 +/- 0.3. We used the USNO-B star at RA=18:37:55, Dec=+62:44:32 to derive the R2 magnitude. Analysis continues to better characterize the rise of the emission from the OT. This message can be cited.