[vsnet-grb-info 13445] GRB 130605A: Continued Skynet/PROMPT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14778
SUBJECT: GRB 130605A: Continued Skynet/PROMPT observations
DATE:    13/06/06 03:45:50 GMT
FROM:    Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet  <atrotter at physics.unc.edu>

A. Trotter, A. Lacluyze, D. Reichart, J. Haislip, T. Berger, M. Carroll, 
H. T. Cromartie, R. Egger, A. Foster, C. Foster, N. Frank, K. Ivarsen, 
D. James, M. Maples, J. Moore, M. Nysewander, E. Speckhard, P. Taylor 
and J. A. Crain report

Skynet observed the Swift/BAT localization of GRB 130605A (Holland et 
al., GCN 14773, Swift trigger #557508) with three 16" telescopes of the 
PROMPT array at CTIO, Chile,  starting at 2013-06-05, 23:43:23 UT 
(t=101s post-trigger), and continuing until t=3h. Exposure lengths range 
from 10s at early times to 160s at later times.  Multiple 160s exposures 
were stacked at later times to increase sensitivity.

We detect a fading afterglow in B, V and I bands at the position 
reported by Nicuesa Guelbenzu et al. (GCN 14774), at:
RA   08:50:08.6
Dec -33:27:40.3

 From t=1.7m to t=9m, the afterglow fades with an approximate temporal 
index alpha~-0.7, after which it steepens to alpha~-1.4.  A preliminary 
light curve is at:
http://www.skynet.unc.edu/grb/grb130605a.png

Magnitudes are in the Vega system, calibrated to 3 APASS stars in the 
field, and are not corrected for the expected Milky Way extinction of 
E(B-V)=1.12 (Schlegel et al. 1998), which, assuming R_V=3.1, corresponds to:
band      B       V       I
A_lambda  1.57    1.17    0.71

No further Skynet observations are scheduled.