[vsnet-grb-info 13396] GRB 130729A: GROND upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14730
SUBJECT: GRB 130729A: GROND upper limits
DATE:    13/05/30 15:53:49 GMT
FROM:    Sylvio Klose at TLS Tautenburg  <klose at tls-tautenburg.de>

K. Varela (MPE Garching), S. Klose, A. Nicuesa Guelbenzu (both TLS 
Tautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND 
team:

We observed the field GRB 130529A (Swift trigger 556930; D' Elia et al., 
GCN 14717) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al. 
2008, PASP 120, 405) mounted at the 2.2m MPG/ESO telescope at La Silla 
Observatory (Chile).

Observations started at 07:10 UT on May 30, about 20 hours after the 
trigger at a mean seeing of 1.7 arcsec and a mean airmass of 2. Inside 
the enhanced 1".4 XRT error circle (Osborne et al., GCN 14723), we do not 
detect any source. Based on an observation with 150 min integration time 
in g'r'i'z' and 124 min integration time in JHKs, we estimate preliminary 
3-sigma upper limits (all in the AB system) of

g' > 24.3,
r' > 24.6,
J  > 21.8,
H  > 21.1.

We note that the field is rich in galaxies. Within 10 arcsec around the 
XRT error circle are at least three objects (also visible on DSS2), with 
the most extended one an edge-on galaxy about 6" in diameter. The bad 
seeing prevents at the moment a more detailed classification of the other 
objects.

Magnitudes are calibrated against GROND zero points (g'r'i'z') as well as 
2MASS field stars (JHKs) and, as usual, are not corrected for Galactic 
extinction along the line of sight.