GCN Circular 10174

Subject

GRB 091117: Magellan optical observations

Event

Date

2009-11-19T06:06:15Z (17 years ago)

From

Edo Berger at Harvard <eberger@cfa.harvard.edu>

E. Berger (Harvard) and J. Mulchaey (OCIW) report:

"We obtained optical r-band observations of the BAT error circle of GRB 
091117 (GCN #10171Loading...
 
 ) with IMACS on the Magellan/Baade 6.5-m telescope 
starting on 2009 Nov 19.06 UT.  A comparison to DSS images reveals no 
new sources brighter than the DSS limit of about 21 mag.

The galaxy coincident with the XRT source within the BAT error circle 
(GCN #10173Loading...
 
 ) has a face-on spiral morphology.  We find a single apparent 
point source coincident with one of the spiral arms.  This object may be 
the optical afterglow of GRB091117 or an unrelated bright HII region. 
Additional observations are planned to determine if the source exhibits 
fading behavior.

An image of the galaxy is available from:
	http://www.cfa.harvard.edu/~eberger/GRB091117_Magellan.gif