[vsnet-grb-info 2791] GRB 060121: Gemini Late-time Observations

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4628
SUBJECT: GRB 060121: Gemini Late-time Observations
DATE:    06/02/01 23:40:43 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko at srl.caltech.edu>

S. B. Cenko, E. Ofek (Caltech), D. B. Fox (Penn State), and E. Berger
(Carnegie) report on behalf of a larger collaboration:

We have imaged the region of the short-hard GRB060121 (GCNs 4550, 4551)
with the GMOS instrument on the Gemini North Telescope.  Images consisted
of 3 x 360 s exposures taken in r' and 5 x 210 s exposures taken in i' at
a mean epoch of approximately Feb. 1.55.  The 3-sigma limiting magnitude
of these images, estimated with respect to the SDSS field calibration (GCN
4554), is approximately r' > 25.6, i' > 25.4.

We find no evidence for any source within 0.5" of the transient reported
by Malesani et al. (GCN 4561) to the limits stated above.  However, within
the XRT error circle (GCN 4560), approximately 1" to the east of the OT
position, we find evidence for a marginal source.  The coordinates of
this source (J2000.0) are:

	RA: 09:09:52.019
	Dec: +45:39:45.45

We estimate photometry for this object as r' ~ 26.4, i' ~ 26.0, although
the errors on these measurements are very large due to 1) the faintness of
the object, and 2) an unexpectedly large scatter in the
photometric zeropoint.  We note that this position likely coincides with
the possible identification of a host galaxy in the NIR by Hearty et al.
(GCN 4604).