[vsnet-grb-info 13271] GRB 130427A: Ten nights of Skynet/PROMPT/GORT observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14608
SUBJECT: GRB 130427A: Ten nights of Skynet/PROMPT/GORT observations
DATE:    13/05/08 19:14:43 GMT
FROM:    Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet  <atrotter at physics.unc.edu>

A. Trotter, D. Reichart, J. Haislip, A. LaCluyze, K. McLin, L. Cominsky, 
T. Berger, H. T. Cromartie, R. Egger, A. Foster, N. Frank, K. Ivarsen, 
M. Maples, J. Moore, M. Nysewander, E. Speckhard, and J. A. Crain report:

Skynet continued observing the Swift/XRT localization of GRB 130427A 
(Maselli et al., GCN 14448, Swift trigger #554620) with four 16" 
telescopes of the PROMPT array at CTIO, Chile (BVRI bands), and with the 
14" GLAST Optical Robotic Telescope (GORT) at the Hume Observatory in 
California (RcIc bands). Our observations span 10 nights, from t=0.65 to 
10.8 days post-trigger. Skynet has taken 2684 160-second exposures on 
the 4 PROMPT telescopes, and 360 160-second exposures on GORT, or a 
total of over 135 hours on source. We performed photometry on each 
exposure, calibrated to two SDSS stars in the field. We stacked 
exposures to improve sensitivity, in groups ranging from 3 exposures on 
night 1, to 60 exposures on night 10.

We detect a fading afterglow in BVRI at the position reported by Elenin 
et al. (GCN 14450), which is ~50" south of the initial XRT localization.