[AAVSO-HEN] GRB090618: P60 Optical Afterglow

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  9513
SUBJECT: GRB090618: P60 Optical Afterglow
DATE:    09/06/18 08:49:37 GMT
FROM:    S. Bradley Cenko at Caltech  <cenko at srl.caltech.edu>

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

We have imaged the field of GRB090618 (Swift trigger 355083) with the
automated Palomar 60-inch telescope beginning at 08:30 UT on 18 June 2009
(approximately 2 minutes after the burst).  At the edge of the XRT error
circle we detect a bright point source with coordinates:

	RA: 19:35:58.68  Dec: +78:21:24.4 (J2000.0)

Using several SDSS stars in the field as reference, we estimate
an initial magnitude of r' ~ 13.8.  Given the brightness of the source,
we consider it highly likely to be the optical afterglow of GRB090618.

Further observations are ongoing.