[vsnet-grb-info 20442] GRB 180325A: Optical Photometry with SLKT

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22538
SUBJECT: GRB 180325A: Optical Photometry with SLKT
DATE:    18/03/25 06:42:44 GMT
FROM:    Peter Garnavich at U of Notre Dame  <pgarnavi at nd.edu>

C. Littlefield and P. Garnavich (Notre Dame) report:

We observed the field of GRB 180325A (GCN 22532)  with the
0.8-m Sarah L. Krizmanich Telescope at the University of
Notre Dame. Unfiltered CCD images were obtained
under hazy conditions beginning 1.5 hours after the
burst. We calibrated the afterglow in SDSS-r using a
nearby star in the Pan-STARRS catalog and constructed
the following light curve:

DateAge     SDSS-r err
(UT)          (hours)
March 25.1403  1.483    19.29  0.14
March 25.1626  2.018    19.52  0.18
March 25.227    3.564    20.1   0.3

Based on SDSS-r magnitudes reported by Heintz et al.
(GCN 22535) and Guidorzi et al. (GCN 22534), we obtain
a rather shallow power-law decay index of 0.31+/-0.05
between 0.5 hours and 2 hours after the burst.