[vsnet-grb-info 16090] GRB 150201A: GROND upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17372
SUBJECT: GRB 150201A: GROND upper limits
DATE:    15/02/02 14:54:42 GMT
FROM:    Fabian Knust at MPE/GROND  <fknust at mpe.mpg.de>

F. Knust, T. Schweyer, J. Bolmer, J. Greiner (all MPE Garching) report on behalf of the GROND team: 

We
 observed the field of GRB 150201A (Swift trigger 629302; J. K. Cannizzo
 et al., GCN #17368) 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 ESO La
 Silla Observatory (Chile). Observations
 started at  00:47 UT on 2015-02-02, 11hrs after the GRB trigger. They 
were performed at an average seeing of 1.64" and at an average airmass 
of 2.1. We do not detect a source within the Swift-XRT error circle reported by J.P. Osborne et al. (GCN #17369) down to 

g' > 23.2 mag, r' > 23.1 mag, i' > 23.5 mag, z' > 23.6 mag, J > 21.5 mag, H > 21.0 mag, and K > 19.4 mag. 
The
 given limits are derived based on calibrating the images against GROND 
zeropoints and 2MASS field stars and are not corrected for the Galactic 
foreground extinction corresponding to a reddening of E_(B-V)= 0.012 in 
the direction of the burst (Schlegel et al. 1998).