[vsnet-grb-info 4236] GRB 070125: Continued P60 Observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6034
SUBJECT: GRB 070125: Continued P60 Observations
DATE:    07/01/26 11:02:12 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko at srl.caltech.edu>

S. B. Cenko (Caltech) reports on behalf of a larger collaboration:

We have continued to monitor the proposed optical afterglow of GRB 070125
(GCN 6028) with the Palomar 60-inch telescope.  We began a new series of
R-band observations at ~ 9:29 UT 26 Jan.  Using 50 point sources from the
2MASS catalog, we have refined the astrometry of our imaging.  The updated
position (J2000.0) for the optical candidate is:

	RA: 07:51:17.767, Dec: +31:09:04.11

with an uncertainty of +/- 0.3" in each coordinate.  The position of the
source is consistent between the two epochs, placing an upper limit on any
proper motion of <~ 0.06 arcsec / hr.  Furthermore, from a preliminary
analysis of the photometry, we find evidence the source has faded by ~
0.13 mag between our two epochs.  Observations and analysis are
continuing.

Given the unusual nature of the spectrum of this object (Prochaska et
al., GCNs 6031 & 6032), we urge further optical monitoring to confirm
this object is indeed the optical afterglow of GRB 070125.