[vsnet-grb-info 7647] GRB 090423: UKIRT K-band observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9202
SUBJECT: GRB 090423: UKIRT K-band observations
DATE:    09/04/23 10:51:23 GMT
FROM:    Nial Tanvir at IofA U.Cambridge  <nrt at ast.cam.ac.uk>

N. Tanvir (U. Leicester), A. Levan (U. Warwick), T. Kerr (JACH),
T. Wold (JACH)

We observed the field of GRB 090423 with WFCAM on UKIRT, beginning at
08:16 (UT), approximately 20 minutes post-burst.  We detect a faint
source in the K-band image just outside the revised XRT error circle,
at coordinate:

 09 55 33.29  +18 08 57.8 (J2000, estimated uncertainty 0.3 arcsec)

The source has a magnitude K~17.5, but does not appear in SDSS images,
and therefore is very red. The image is also extended in the E-W
direction, and so might be (or include) a dusty host galaxy.  However,
we caution that the images are slightly trailed and so further work is
required to determine whether this source is a point source or not.