[vsnet-grb-info 14651] GRB 140302A: GROND confirmation of the afterglow

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15965
SUBJECT: GRB 140302A: GROND confirmation of the afterglow
DATE:    14/03/12 14:08:14 GMT
FROM:    Jonny Elliott at MPE/GROND  <jonnyelliott at mpe.mpg.de>

J. Elliott (MPE Garching), S. Schmidl (TLS Tautenburg), J.Greiner, J. F.
Graham, M. Tanga (all MPE Garching) report on behalf of the GROND team:

We re-observed the field of GRB 140302A (Swift trigger 589685; Pagani et
al., GCN #15901) 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).

Observations started at 07:18 UT on 4th March 2014, 2 days after the GRB
trigger. They were performed at an average seeing of 1.1" and at an
average airmass of 1.3.

We no longer detect the source noted in our previous observations (Elliott
et al.; GCN #15903) that had a magnitude of r' = 23.7 +/- 0.2 mag. For a
total exposure of 1.2 hours we obtain an upper limit (AB) of r' > 25.2 mag
and confirm this as the afterglow of GRB 140302A.

The given limit is derived based on calibrating the image against GROND
zeropoints and is not corrected for the Galactic foreground extinction
corresponding to a reddening of E(B-V)= 0.52 mag in the direction of the
burst (Schlegel et al. 1998).