[vsnet-grb-info 15319] GRB 140719A: GROND Afterglow candidate

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  16611
SUBJECT: GRB 140719A: GROND Afterglow candidate
DATE:    14/07/20 07:32:00 GMT
FROM:    Jan Bolmer at MPE/Garching  <jan at bolmer.de>

We observed the field of GRB 140719A (Swift trigger 605612; Cummings et 
al.,
GCN 16606) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 
2008,
PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla
Observatory (Chile).

Observations started at 22:59 UT on July 19, 2014, 16.8 hrs after
the GRB trigger. They were performed at an average seeing of 1.1“ and 
at
an average airmass of 1.5.

We find a faint source inside the XRT error circle given in Evans et 
al.
(GCN 16607) at coordinates RA, Dec = 171.60123, -50.13466, which is 
equal
to:

RA  (J2000): 11:26:24.3
Dec (J2000): -50:08:04.8

with an uncertainty of 0.5“ in each coordinate.

Based on a total exposures of 3000 seconds in g'r'i'z' and 1200 seconds 
in
JHK, at a mid-time of 18.4 hrs after the burst, we measure the 
following
preliminary magnitudes (all in AB):

g' > 25.3,
r' = 23.7 +/- 0.2,
i' = 22.9 +/- 0.2,
z' > 23.8,
J  > 21.4,
H  > 20.9 and
K  > 19.5.

At present we cannot confirm whether the source is fading.

Given magnitudes are calibrated against GROND zeropoints as well as
2MASS field stars and are not corrected for the expected Galactic
foreground extinction corresponding to a reddening of E_(B-V) = 0.12 
mag
in the direction of the burst (Schlegel et al. 1998).