GCN Circular 12771
Subject
GRB 111228A: P60 Observations
Event
Date
2011-12-29T20:00:39Z (15 years ago)
From
S. Bradley Cenko at Caltech <cenko@srl.caltech.edu>
S. B. Cenko (UC Berkeley) reports on behalf of a larger collaboration:
We have imaged the field of GRB111228A (Ukwatta et al., GCN 12737) with
the automated Palomar 60 inch telescope. Observations were obtained in
the r' and i' filters beginning at 10:27 UT on 2011 December 29 (~ 18.9
hours after the Swift trigger).
We detect the optical afterglow with a magnitude of r' = 20.3 +/- 0.1 mag
(AB, calibrated with respect to several point sources from the Sloan
Digital Sky Survey in the field). Compared with previous reported
measurements of the afterglow brightness, this suggests a steeper decay
than observed at early times (e.g., Klotz et al., GCN 12742).
Further observations are planned.