A.Trotter, D. Reichart, J. Haislip, N. Frank, A. LaCluyze, J. Moore, T.
Berger, H. T. Cromartie, R. Egger, A. Foster, K. Ivarsen, M. Maples, M.
Nysewander, and J. A. Crain report:
Skynet observed the Swift/XRT localization of GRB 131117A (Page et al.,
GCN 15490, Swift trigger 577968) with four 14" telescopes of the PROMPT
array at Cerro Tololo, Chile, beginning 91s after the trigger,
simultaneously in the BVRI bands. We detect a fading optical source in
V, R and I bands at:
Dec -31:45:44.4 (J2000.0)
which is within the error circle reported by the Swift XRT. The
afterglow fades from R~17.2 at t=1.5min to R~19.7 at t=24min.
Photometry is calibrated to six APASS-DR7 stars in the field, and has
not been corrected for Galactic foreground extinction.
A preliminary light curve is at: http://skynet.unc.edu/grb/grb131117a.png
Skynet observations are ongoing.