GCN Circular 15956
Subject
GRB 140311A: Nanshan afterglow decay
Event
Date
2014-03-12T00:51:27Z (13 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
D. Xu (DARK/NBI), C.-H. Bai, X. Zhang, A. Esamdin, L. Ma (XAO) report:
The previously reported afterglow candidate (Xu et al., GCN 15947) has
been decaying throughout our R-band observations. Part of the
photometry are listed below
Tmid (hr) Mag(R) MagErr(R)
2.06778 21.06 0.10
1.53056 20.80 0.10
0.49306 19.96 0.10
All magnitude are calibrated with the following three SDSS stars using
Lupton (2005) transformation:
SDSS J135709.54+003731.9 m(r)=16.81, m(i)=16.30
SDSS J135716.45+003657.3 m(r)=16.41, m(i)=16.10
SDSS J135713.38+003942.0 m(r)=18.57, m(i)=18.47
Together with measurements in Klotz et al. (GCN 15952) and D'Avanzo et
al. (GCN 15953), it shows that the optical afterglow peaks at ~0.23 hr
post-burst and is decaying roughly as F(t) ~ t^-0.75 since ~0.5 hr
post-burst.