[vsnet-grb-info 16464] GRB 150424A: Keck detection of optical afterglow

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17745
SUBJECT: GRB 150424A: Keck detection of optical afterglow
DATE:    15/04/24 10:19:56 GMT
FROM:    Daniel Perley at Caltech  <dperley at astro.caltech.edu>

D. A. Perley (Caltech) and N. J. McConnell (IfA) report:

We observed the field of short-duration GRB 150424A (Beardmore et al., 
GCN 17743) with the Low Resolution Imaging Spectrometer (LRIS) on the 
Keck I 10m telescope.  Three 120-second imaging exposures in g- and 
R-bands were acquired between 09:15 and 09:26 UT (approximately 1.6 
hours after the GRB trigger), at low elevation through moderate cloud cover.

In both filters we detect a bright (R~20 mag) source, not visible in 
DSS, at the following location inside the XRT error circle:

  RA = 10:09:13.381
dec = -26:37:51.50
(+/- 0.5" or less)

We suggest this as the optical afterglow of GRB 150424A.

We also note the presence of a large galaxy (resolved in DSS) 5 arcsec 
to the southwest.