TITLE:   GCN CIRCULAR
NUMBER:  581
SUBJECT: GRB000301C, optical observations
DATE:    00/03/04 21:16:26 GMT
FROM:    Peter Garnavich at Center for Astrophysics  <peterg@mars.harvard.edu>

P. Garnavich (Notre Dame), P. Barmby,  S. Jha, K. Stanek (CfA)  report:

We again imaged the candidate optical counterpart of GRB000301C
with the FLWO 1.2m telescope and R-band filter on 2000 Mar. 4.38 (UT)
and estimated its magnitude based on the calibration stars
given in GCN 573. We find R=20.56 +/- 0.05 which suggests a rather
slow decline rate. Using the magnitude estimates from Veillet (GCN 575),
Fynbo et al. (GCN 576), Halpern et al. (GCN 578) and Castro-Tirado et al.
(GCN 579) we find the data best fit a single power-law index
of -1.07+\-0.13 .  However, using data taken since Mar 3.5 (UT) gives
an even more shallow slope of -0.8 +\-0.2 and suggests a
possible flattening of the decay rate.