TITLE: GCN CIRCULAR NUMBER: 7689 SUBJECT: GRB 080506: optical observation from Ondrejov DATE: 08/05/07 05:09:29 GMT FROM: Matus Kocka at Monteboo Obs,Masaryk U,Brno M. Kocka, M. Nekola, J. Strobl, R. Hudec, C. Polasek (AsU AV CR, Ondrejov), M. Jelinek, P. Kubanek (IAA CSIC, Granada), F. Munz (IASF/INAF, Bologna) A. de Ugarte Postigo (ESO) report We observed the OT of the GRB080506 (Baumgartner et al, GCN 7685) with the 0.5m telescope at ASU Ondrejov in Czech Republic. We obtained a set of R-band exposures at ~7.1h after the GRB. Using the same calibration as Kawabata et al. (GCN 7686) we find the brightness R ~ 21.2+-0.4. This message may be cited.