TITLE: GCN CIRCULAR NUMBER: 11060 SUBJECT: GRB 100805A: IAC80 BVR-band observations DATE: 10/08/05 14:05:26 GMT FROM: Javier Gorosabel at IAA-CSIC J. Gorosabel (IAA-CSIC), M. Chioare Diaz-Martin (IAC), R. Iglesias Marzoa (Univ. of La Laguna), M. Jelinek (IAA-CSIC), report on behalf of a larger collaboration: "We have acquired BVR-band images of the GRB 100805A (Hoversten et al. GCNC 11047) field with the 82-cm IAC80 telescope on the Observatory of Teide, Tenerife, Spain. The optical afterglow (Hoversten et al. GCNC 11047; Cenko et al. GCNC 11050, GCNC 11051; Gomboc et al. GCNC 11052; Gorosabel et al. GCNC 11054; Nissinen et al. GCNC 11056) is detected in the three optical bands with an approximate magnitude of R~19.3 on Aug. 5.2046 UT (mean observing time, ~42 minutes post burst). The calibration is based on USNO B1.0 field stars."