[vsnet-grb-info 2052] GRB 050826: Optical Candidate

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3891
SUBJECT: GRB 050826: Optical Candidate
DATE:    05/08/27 12:09:34 GMT
FROM:    Jules Halpern at Columbia U.  <jules at astro.columbia.edu>

J. P. Halpern (Columbia U.) reports on behalf of the MDM Observatory
GRB follow-up team:

"I observed the error box of GRB 050826 (Swift trigger #152113, GCN #3884)
in the R band with the MDM 1.3m telescope for 75 minutes on each of two
consecutive nights.  A fading object not visible on the Digitized Sky
Survey is present at coordinates

	(J2000) 05:51:01.59, -02:38:35.4 (+/- 1")

which is 8" from the revised Swift XRT position (error radius 6", GCN #3889).
The epochs and magnitudes are:

       ---------------------------------------------------
        Date(UT)   Time(UT)    t-t0(hours)     R(mag)
       ---------------------------------------------------
        Aug. 26   10:42-11:57   4.40- 5.65   21.0 +/- 0.2
        Aug. 27   10:43-11:58  28.42-29.67   21.6 +/- 0.2
       ---------------------------------------------------

The indicated errors are systematic at this stage of the analysis,
but the difference between the two observations is not affected by
systematics.  Improvements in precision of position and magnitudes
will be forthcoming from these data.  These preliminary magnitudes
should not be used in formal analyses.

I also note that this location suffers from significant Galactic extinction,
E(B-V)=0.59, A(R)=1.57, according to Schlegel et al. (1998)."