TITLE: GCN CIRCULAR NUMBER: 573 SUBJECT: GRB000301C, optical observations DATE: 00/03/03 19:17:14 GMT FROM: Peter Garnavich at Center for Astrophysics P. Garnavich (Notre Dame), P. Barmby, S. Jha, K. Stanek (CfA) report: We imaged the ASM error box (GCN 568) of GRB000301C with the FLWO 1.2m telescope and R-band filter on 2000 Mar. 3.51 (UT) and detect the optical candidate reported by Fynbo et al. (GCN 570). Using Landolt standards taken during the night, we find a preliminary magnitude of R=20.28 +\- 0.05 mag. This is very close to the Fynbo et al. estimate taken some 7 hours earlier. However, given the quoted errors for the two measurements there is room for some variability over this time. Further observations are needed to confirm this source as the GRB afterglow. We have calibrated the following stars in R to use as comparisons: star Offset East Offset North R A -6" -1" 18.05 +/- 0.05 B -4 -89 18.48 C 70 -55 18.62 D -7 62 17.04 Offsets are in arcsec from the GRB candidate with positive offsets east and north.