J. Graham (MPE Garching), S. Schmidl (TLS Tautenburg), and J. Greiner
(MPE Garching) report on behalf of the GROND team:
We observed the field of GRB 140515A (Swift trigger 599037; D'Avanzo et
al., GCN 16267) 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
Observations started at 22:53 UT on March 15, 2014, 13.7 hrs after
the GRB trigger. They were performed at an average seeing of 0.9" and at
an average airmass of 1.4.
We detect the afterglow reported by Chornock et al. (GCN 16269).
Based on a total exposure of 50 min in g'r'i'z' and 40 min in JHK, at
a mid-time of 17.0 hrs after the burst, we measure the following
preliminary magnitudes (in AB):
g' > 24.1 mag,
r' > 24.5 mag,
i' > 24.2 mag,
z' = 22.1 +/- 0.1 mag,
J = 20.9 +/- 0.2 mag,
H = 20.9 +/- 0.2 mag, and
K > 19.1 mag.
Based on these data, the photometric redshift is z= 6.5 +/-0.2, which is
consistent with the spectroscopic redshift reported by Chornock et al.
Given magnitudes are calibrated against SDSS (g'r'i'z') as well as 2MASS
(JHK) field stars and are not corrected for the expected Galactic
extinction corresponding to a reddening of E_(B-V) = 0.02 mag in the
direction of the burst (Schlegel et al. 1998).