TITLE:   GCN CIRCULAR
NUMBER:  8984
SUBJECT: GRB 090313: SDSS object underlying the optical afterglow position
DATE:    09/03/13 13:26:03 GMT
FROM:    Edo Berger at Harvard  <eberger@cfa.harvard.edu>

E. Berger (Harvard) reports:

"Inspection of archival Sloan Digital Sky Survey images reveals a faint
(and apparently extended) object near the position of the optical
afterglow (GCN 8979) of GRB 090313 (GCN 8980).  The object is located at:
	RA = 13:13:36.08
	DEC = 08:05:51.06	(J2000)
which is 2.3" away from the optical afterglow position provided by
Chornock et al. (GCN 8979).  The SDSS model magnitudes of this object are:
	g = 22.8+/-0.3
	r = 21.6+/-0.16
	i = 21.1+/-0.18
	z = 20.7+/-0.4

A much brigher galaxy is located 17.8" away from the optical afterglow
position at:
	RA = 13:13:35.29
	DEC = 08:05:38.54	(J2000)
which we consider to be the galaxy mentioned by Chornock et al. (given its
brightness).  The SDSS model magnitudes of this galaxy are:
	u = 17.07+/-0.01
	g = 16.02+/-0.01
	r = 15.57+/-0.01
	i = 15.32+/-0.01
	z = 15.14+/-0.01

A direct determination of the afterglow redshift is required in order to
determine which of the two objects is the host galaxy."