TITLE: GCN GRB OBSERVATION REPORT NUMBER: 743 SUBJECT: GRB000630, optical observations DATE: 00/07/02 00:40:28 GMT FROM: Jochen Greiner at Astrophys.Inst. Potsdam,Germany J. Greiner (AIP, Potsdam), A. Henden (USRA/USNO), on behalf of the USNO GRB team, S. Merlino, J. Masegosa (IAA-CSIC Granada), Felipe Hoyo (CAHA, Almeria), A.J. Castro-Tirado (LAEFF-INTA, Madrid, and IAA-CSIC, Granada), S. Klose (Thueringer Landessternwarte, Tautenburg), J. Gorosabel (DSRI, Copenhagen) report on behalf of a larger collaboration: R-band images of the GRB 000630 error box (Hurley et al., GCN #736) were acquired according to the following table (note that the USNOFS observations were made on two field centers, covering 100% of the error box): Date (UT; Start) Telescope Exp.(s) Coverage Seeing Lim. Mag. ------------------------------------------------------------------------ 0006 30.865 Calar Alto 2.2m 2*600 90% 1.4" 23.0 0007 1.181 USNOFS 1.0m 4*600 60% south 1.9" 22.5 0007 1.181 USNOFS 1.0m 4*600 60% north 1.9" 22.5 0007 1.292 USNOFS 1.0m 6*600 60% south 2.2" 22.5 0007 1.292 USNOFS 1.0m 4*600 60% north 2.2" 22.5 0007 1.894 Calar Alto 2.2m 2*900 100% 1.3" 24.0 ------------------------------------------------------------------------ Photometric calibration was achieved with preliminary BVRcIc all-sky photometry for the field of GRB000630 (Henden, GCN #742). Comparison between these four epoch observations did not reveal any object brighter than R ~ 22.5 mag showing variability larger than 0.3 mag. We confirm the findings of Jensen et al. (GCN #739) on the Bartolini et al. (GCN #737) object which appears constant in our images. We also do not find any object at the radio source position reported by Berger et al. (GCN #738) down to R = 23.5 mag.