[vsnet-grb-info 7117] GRB 081221: Gemini-N nIR imaging

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8698
SUBJECT: GRB 081221: Gemini-N nIR imaging
DATE:    08/12/22 13:49:28 GMT
FROM:    Nial Tanvir at IofA U.Cambridge  <nrt at ast.cam.ac.uk>

N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick),
K. Wiersema (U. Leicester), A. S. Fruchter, J. Graham (STScI)
report:

We observed the field of GRB 081221 with Gemini-N/NIRI, starting
22 Dec 2008 04:20UT, approximately 12 hours post burst.

Our preliminary analysis reveals a faint point source in the enhanced
XRT error circle (GCN 8690) with magnitude K~20.1 at position:

01:03:10.19
-24:32:52.2

relative to three 2MASS stars in the field.  The source is also
marginally detected in J and H.

We suggest this is most likely the afterglow of GRB 081221, but that
its faintness and red colour (H-K>~2) argue for a dusty sight-line
rather than a high redshift as the explanation for the absence of an
optical detection (GCN 8688 and GCN 8689).

Further analysis is ongoing.

We thank Ricardo Schiavon (Gemini) for his assistance in obtaining
these observations.