GCN Circular 18607
Subject
GRB 151114A: GROND Detection of the Optical/NIR Afterglow Candidate
Event
Date
2015-11-15T16:10:09Z (10 years ago)
From
Jan Bolmer at MPE/Garching <jan@bolmer.de>
J. Bolmer, F. Knust and J. Greiner (all MPE Garching) report on behalf of
the GROND team:
We observed the field of GRB 151114A (Swift trigger 663490; Siegel et
al., GCN #18599) 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 the ESO La
Silla Observatory (Chile).
Observations started at 04:59 UT on 2015-11-15, 19.5hrs after the GRB
trigger. They were performed at an average seeing of
1.8" and at an average airmass of 1.5.
We found a single point source within the 1.8" Swift-XRT and 0.45" Swift-UVOT error
circles reported by Beardmore et al. (GCN #18600) and Kuin et al. (GCN #18602) at
RA, Dec = 120.94299, -61.02778
RA (J2000.0) = 08h 03m 46.32s
DEC (J2000.0) = -61d 01' 40.0"
with an uncertainty of 0.3" in each coordinate.
Based on 25.2 min of total exposures in g'r'i'z' and 25.5 min in JHK, we
estimate preliminary magnitudes (all in AB system) of
g' = 23.7 +/- 0.3 mag,
r' = 23.2 +/- 0.2 mag,
i' = 23.1 +/- 0.3 mag,
z' = 23.3 +/- 0.4 mag,
J > 21.4 mag,
H > 20.9 mag, and
K > 19.5 mag.
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)=0.17 mag in the
direction of the burst (Schlegel et al. 1998).