TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4076 SUBJECT: GRB 051008: R-band upper limit DATE: 05/10/09 16:39:12 GMT FROM: Patrizia Ferrero at TLS Tautenburg P. Ferrero and S. Klose, Thueringer Landessternwarte Tautenburg, report: We have further analysed the R-band images of the error box of GRB 051008 obtained on October 8.7514 UT (mean time, i.e. 1.6 hrs after the burst) with the Tautenburg Schimdt telescope, previously reported by Klose & Hoegner (GCN 4072). Photometric calibration was performed using the USNO-A2.0 catalog (Monet et al. 1996). We do not detect any souce in the XRT error circle (Perri et al., GCN 4073) as well as at the position of the bright radio source reported by Cameron et al. (GCN 4074) down to an R-band magnitude of about 19.5. This finding is not unusual compared to what is known so far about the properties of Swift afterglows (cf. Berger et al., astro-ph/0505107). This message may be cited.