TITLE: GCN GRB OBSERVATION REPORT NUMBER: 774 SUBJECT: GRB000812, TNG R-band observations DATE: 00/08/17 17:28:25 GMT FROM: Nicola Masetti at ITeSRE,CNR,Bologna N. Masetti, E. Palazzi (ITESRE, CNR, Bologna), E. Pian (OATs, Trieste), R. Cosentino, F. Ghinassi, A. Magazzu', S. Benetti, (TNG), on behalf of a larger collaboration, report: "We acquired optical R-band images of the central part of the GRB000812 error box (Hurley et al., GCN #770) on 2000 August 16.961 UT with TNG+Dolores for a total exposure time of 30 minutes. Seeing was 1.1 arcsec. The pointing was centered on the uncatalogued radio source found by Frail et al. (GCN #771). The observations were heavily hampered by the full moon and by a 8th magnitude star located ~40 arcsec from the radio position; nevertheless, they were considerably deeper than the DSS-II. Photometric calibration was performed using USNO-A2.0 catalog stars. No new object brighter than the DSS-II limit is apparent all over the image. Also, no object down to a 3-sigma limiting magnitude R ~ 23 is present inside the radio source error box.". This message can be cited.