GCN Circular 16693

GRB 140815A: GROND afterglow candidate

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

We observed the field of GRB 140815A (Mereghetti et al., GCN #16690
Not found
 
 
)
simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120,
405) mounted at the 2.2m MPG telescope at La Silla Observatory (Chile).

Observations started at 08:17 UT on 16 August 2014, 10.37 hours after
the INTEGRAL trigger. They were performed at an average seeing of 1".3
and at an average airmass of 1.5.

We report the presence of a source within the XRT error circle
(Mangano et al., GCN #16691
Not found
 
 
) at:

RA(J2000) = 86.89231 = 05h 47m 34.15s
Dec(J2000) = -8.68021 = -08d 40' 48.7"

which has the following preliminary magnitudes and upper limits (all in
AB) at a mid-time of 09:30 UT:

g' > 24.0
r' > 24.0
i' = 23.3 +/- 0.3
z' = 22.2 +/- 0.2
J  = 21.2 +/- 0.3
H  > 20.3
K  > 19.3

At the moment we cannot determine whether or not the source is fading.

Given magnitudes are calibrated against GROND zero points as well as 2MASS
field stars (JHK) and are not corrected for the expected Galactic
foreground extinction corresponding to a reddening of E_(B-V)=1.10 mag in
the direction of the burst (Schlafly & Finkbeiner 2011).