GCN Circular 14413

Subject

GRB 130420A: Weihai Optical Observations

Date

2013-04-20T13:57:41Z (11 years ago)

From

Dong Xu at DARK/NBI <dong.dark@gmail.com>

D. Xu (DARK/NBI), C. Cao, S.M. Hu (SDU) report:

We observed the field of GRB 130420A (Page et al., GCN 14406) using
the 1m telescope located in Weihai, Shandong Province, China.
Observations started at 11:41:32 UT, 2013-04-20 (i.e., 4.218 hr after
the BAT trigger) and 12x180s I-band frames were obtained.

The optical afterglow (Page et al., GCN 14406) is clearly detected in
our stacked image to be of I=19.4 mag, calibrated with nearby USNO B1
stars. It has decayed by about 0.5 mag, compared to the measurement in
Watson et al. (GCN 14409).

We thank Dayong Ren for carrying out these observations.