GCN Circular 17335
Subject
GRB 150120B: Additional P60 observations
Date
2015-01-21T03:32:27Z (9 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech) and S. B. Cenko (NASA/GSFC) report:
We obtained further observations at the position of the optical
afterglow (Perley, GCN 17315) of GRB 150120B (D'Elia et al., GCN 17314)
with the Palomar 60-inch robotic telescope on the night of 2015-01-21
UT. In a combined stack of five 300-second r-band exposures we no
longer detect any significant emission at the location of the optical
afterglow. We estimate a limiting magnitude of r>22.7 mag (3 sigma) at
a mid-time of 02:32:27 UT, t=0.799 days after the GRB. Relative to our
previous observations, this suggests a decay power-law slope of at least
alpha>0.75.