TITLE: GCN GRB OBSERVATION REPORT NUMBER: 576 SUBJECT: GRB 000301C: OT confirmed DATE: 00/03/03 23:21:41 GMT FROM: Brian Lindgren Jensen at U.of Copenhagen J. P. U. Fynbo (U. of Aarhus), B. L. Jensen, J. Hjorth, H. Pedersen (U. of Copenhagen), J. Gorosabel (DSRI, Copenhagen) on behalf of a large European GRB Consortium report: "In response to Garnevich et al., (GCN #573), we have carried out photometry of stars A-D of GCN #573 and of the OT proposed by Fynbo et al., (GCN #570). This photometry has been performed on our combined 2000, March 3, 3x900s NOT R-band image of the GRB-field. Using the stars A-D of Garnevich et al. as reference, we derive an R-band magnitude for the OT at UT_mean = March 3.17 of R = 19.94+-0.04. Hence, the candidate OT is fading and we thus propose it as being the optical counterpart to GRB 000301C. The implied power-law decay index from this magnitude and the magnitude measured by Garnevich et al. is rather steep : -1.8 (with this rate, a magnitude of R:20.8 is predicted for March 4.17 UT)."