GCN Circular 15829
Subject
GRB 140213A: GROND Detection of the Optical/NIR Afterglow
Event
Date
2014-02-14T01:45:51Z (12 years ago)
From
Jonny Elliott at MPE/GROND <jonnyelliott@mpe.mpg.de>
J. Elliott, K. Varela (both MPE Garching), D. A. Kann (TLS Tautenburg),
and J. Greiner (MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 140213A (Swift trigger 586569; Holland et
al., GCN #15825) 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 00:25 UT on 14 February 2014, 5 hours after the
GRB trigger, and are continuing. They were performed at an average seeing
of 1.9" and at an average airmass of 1.4.
We find a single point source within the 0.4" Swift-UVOT error circle
reported by Siegel & Holland (GCN #15826) and confirmed by Trotter et al.
(GCN #15828).
Based on the first 4.4 min of total exposures in g'r'i'z' and 4 min in
JHK, we estimate preliminary magnitudes (all in AB) of
g' = 19.7 +/- 0.1 mag,
r' = 19.4 +/- 0.1 mag,
i' = 19.2 +/- 0.1 mag,
z' = 19.1 +/- 0.1 mag,
J = 18.7 +/- 0.1 mag,
H = 18.5 +/- 0.1 mag, and
K = 18.4 +/- 0.1 mag.
The spectral energy distribution is best-fit by a straight power-law with
spectral slope b = 0.8 +/- 0.1.
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)=0.07 mag in the
direction of the burst (Schlegel et al. 1998).