GCN Circular 17386

C. Delvaux, K. Varela and J. Greiner (all MPE Garching) report on behalf
of the GROND team:

We observed the field of GRB 150203A (SWIFT-629578; Ukwatta et al., GCN
#17377) 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 on February 3rd, 2015, at 04:20 UT, 11 minutes after
the GRB trigger. They were performed at an average seeing of 1.2" and at
an average airmass of 2.1. The distance from the moon was only 28 deg.

We do not detect a source inside the 2.1 arcsec error circle reported by
Ukwatta et al. (GCN #17377). Based on a total exposure of 0.83 hours in
g'r'i'z'
and 0.80 hours in JHK, at a midtime of 0.7 hour after the burst, we measure
the following preliminary upper limits (AB magnitudes system):

g' > 23.5 mag,
r' > 23.9 mag,
i' > 24.0 mag,
z' > 24.1 mag,
J > 21.5 mag,
H > 20.9 mag, and
K > 18.6 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) = 0.88 mag in the
direction of the burst (Schlegel et al. 1998).