GCN Circular 8983

Subject

GRB 090313, GROND observations

Event

Date

2009-03-13T10:34:51Z (17 years ago)

From

Sylvio Klose at TLS Tautenburg <klose@tls-tautenburg.de>

A. C. Updike (Clemson University), S. Klose (Tautenburg), C. Clemens
and J. Greiner (MPE Garching) report on behalf of the GROND team:

We observed the field of GRB 090313 (Swift trigger 346386; Mao et al. 
2009, GCN 8980Loading...
 
 ) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 
2008, PASP 120, 405) mounted at the 2.2m ESO/MPI telescope at La Silla 
Observatory (Chile).

Observations started at 09:13 UT on March 13, 7 minutes after the GRB 
trigger. We confirm that the afterglow candidate reported by Chornock et 
al. (GCN 8979Loading...
 
 ) is bright in all bands.

We measure the following preliminary magnitudes at a mean time of about 10 
minutes after the burst (Vega mags):

J = 14.0 +/- 0.1
H = 13.1 +/- 0.1
K = 12.3 +/- 0.1

calibrated against 2MASS field stars. Astrometry gives RA, DEC (J2000) = 
13:13:36.21, +08:05:49.2 (+/- 0.5 arcsec). As already noted by Chornock 
et al., the afterglow is close to a bright galaxy.

These are preliminary data. Data reduction is in progress.