[vsnet-grb-info 14958] GRB 140428A: GROND afterglow confirmation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16252
SUBJECT: GRB 140428A: GROND afterglow confirmation
DATE:    14/05/12 21:05:18 GMT
FROM:    Karla Varela at MPE  <kvarela at mpe.mpg.de>

K. Varela, C. Delvaux, and J. Greiner (all MPE Garching) report on behalf of
the GROND team:

We re-observed the field of GRB 140428A (Swift trigger 597519; Kocevski et
al.,
GCN #16177) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,
PASP 120, 405) mounted at the 2.2 m MPG telescope at La Silla Observatory
(Chile).

A second epoch obtained on May 6th at 02:01 UT, about 7 days after the
trigger,
shows that the source reported by Knust et al. (GCN # 16191) has clearly
faded.
We find z' > 23.3, suggesting that the source has faded by at least 1.9 mag,
and confirming that this was the afterglow of GRB 140428A.