[vsnet-grb-info 15273] GRB 140710A: GROND Detection of NIR Afterglow Candidate

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16565
SUBJECT: GRB 140710A: GROND Detection of NIR Afterglow Candidate
DATE:    14/07/10 12:11:39 GMT
FROM:    Jochen Greiner at MPI  <jcg at mpe.mpg.de>

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

We observed the field of GRB 140710A (Swift trigger 603954; Siegel et al.,
GCN #16563) simultaneously in JHK with GROND (Greiner et al. 2008, PASP
120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla Observatory
(Chile). 

Observations started at 10:48 UT on 2014-07-10, 0.5 hrs after the GRB
trigger, but already in morning twilight and thus without the optical
GROND channels. Observations were performed at an average seeing of 
1.5" and at an average airmass of 2.6.

We found a single point source within the 2.2" Swift-XRT error circle
reported by Siegel et al. (GCN #16563) at

RA (J2000.0) = 02 h 44 m 16.30 s
DEC (J2000.0) = +35d 29' 08.4

with an uncertainty of 0.5" in each coordinate. 

Based on 4 min of total exposure we estimate a preliminary magnitude 
of about
  
J(AB) ~ 20.5 mag

The given magnitude is calibrated against 2MASS field stars and is not
corrected for the expected Galactic foreground extinction corresponding 
to a reddening of E_(B-V)=0.06 mag in the direction of the burst 
(Schlegel et al. 1998).