Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 9408

Subject
GRB 090519: GROND observation
Date
2009-05-20T08:02:04Z (15 years ago)
From
Jochen Greiner at MPI <jcg@mpe.mpg.de>
A. Rossi (Tautenburg), T. Kruehler, J. Greiner and A. Yoldas (all MPE Garching)
report on behalf of the GROND team:

We observed the field of GRB 090519 (Swift trigger 352648, M. Perri et al.,
GCN #9400) simultaneously in g'r'i'z'JHK with GROND mounted at the 2.2m
ESO/MPI telescope at La Silla Observatory (Chile). Observations started on
19 May 2009 at 23:44 UT, 2.5 h after the burst, under challenging sky 
conditions with cirrus.

We detect the afterglow at a position consistent with the enhanced XRT error 
circle and NOT (Thoene et al., GCN #9403). With an exposure time of 40min in 
JHK and 49min in griz, preliminary photometry yields the following AB 
magnitudes:
 
g =25.0 +-0.4
r =23.5 +-0.2
i =23.5 +-0.3
z >23.6
J >21.9
H >20.7
K >19.9

calibrated using SDSS and 2MASS field stars. The quoted magnitudes are not 
corrected for the galactic foreground extinction corresponding to a 
reddening of E_(B-V)=0.04.

The large g-i color as compared to r-i indicates that the Lyman break may
be located in the g' band. Fitting the SED with Hyper-Z results in a 
preliminary photometric redshift of z = 3.9+0.4-0.7, assuming no intrinsic 
extinction.
Looking for U.S. government information and services? Visit USA.gov