[vsnet-grb-info 18188] GRB 160630A: Skynet PROMPT-CTIO observations of the optical afterglow

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19636
SUBJECT: GRB 160630A: Skynet PROMPT-CTIO observations of the optical afterglow
DATE:    16/06/30 18:42:41 GMT
FROM:    Adam S. Trotter at UNC-Chapel Hill/PROMPT/Skynet  <atrotter at physics.unc.edu>

A. Trotter, D. Reichart, J. Haislip, J. Moore, N. Frank, M. Maples, D. Dutton, R. Gao, R. Joyner, J. Martin, M. Paggen, J. A. Crain, K. Ivarsen, A. LaCluyze, and M. Nysewander report:

Skynet observed the Swift BAT/XRT localization of GRB 160630A (Krimm et al., GCN 19624, Swift trigger=702252) with with two 16" telescopes (P5, P6), and two 24" telescopes (P1, P8) of the PROMPT array at CTIO, Chile. Starting at 2016-06-30 04:05 UT and continuing until 07:02 UT (t=60s-3h post-trigger), Skynet took a total of 452 2.5-160s exposures in the I band (P1, P5), V band (P6) and B band (P8).  

We detect a fading optical afterglow in stacked I-band images at the OT position reported by Kann et al. (GCN 19625) and Melandri et al. (GCN 19627), with I~17.4 at t=5m and I~18.6 at t=23m. 

A preliminary light curve is at:
http://www.skynet.unc.edu/grb/grb160630a.png

Preliminary magnitudes are in the Vega System, calibrated to 9 APASS DR9 stars in the field.  Magnitudes have not been corrected for line-of-sight Milky Way dust extinction, with expected E(B-V)=0.43 (Schlafly & Finkbeiner 2011).

No further Skynet observations are scheduled.