TITLE:   GCN CIRCULAR
NUMBER:  9837
SUBJECT: GRB 090817: No host galaxy, no supernova
DATE:    09/08/25 11:16:13 GMT
FROM:    Jules Halpern at Columbia U.  <jules@astro.columbia.edu>

J. P. Halpern and J. Ruan (Columbia U.) report:

We obtained R-band photometry of the USNO-B1.0 object 341-0096763
on 2009 August 21 10:46 UT using the McGraw Hill 1.3m telescope.
In five 300 s exposures in seeing of 1.5"-1.8", there is no evidence
to support the hypothesis of Holland et al. (GCN Circ. 9831) that this
object is the host galaxy of GRB 090817.  The image is consistent
with the stellar point spread function.  Using the reference star of
Rumyantsev et al. (GCN Circ. 9828), we measure R = 19.39+/-0.04,
consistent with their photometry on Aug. 17.

On Aug. 25 09:56 UT, we again obtained five 300 s exposures in seeing
of 1.5".  We measure R = 19.42+/-0.03, 8.4 days after the burst,
which is consistent with all previous measurements.  Thus, there is
no evidence for brightening suggested by Holland et al. (GCN Circ. 9834)
from Swift UVOT observations between 6.5 and 7.1 days.  The set of
consistent magnitudes from day zero in GCN Circ. 9828 to days 4 and 8
in this report are indicative of a chance coincidence with a normal star.