Program: GN-2015B-Q-41

To date, four active asteroids have been suspected of rotational disruption. Our data obtained with Keck II in August 2014 show that one of these objects, P/2012 F5 (Gibbs), has a very short rotation period of 3.24 hr and recently ejected at least four sizable fragments. Given that the rotation period has not been robustly measured for any other fragmented object in the solar system, P/2012 F5 is a unique laboratory for detailed tests of the rotational break-up scenario. We request 7 hr of GMOS-N time in December 2015 to quantify the separations and brightness of the fragments and measure the rotational light curve of the main nucleus at a new epoch. When combined with our earlier Keck II data, these new measurements will provide unprecedented insights into the disruption of this object. In particular, we will be able to quantify the ejection times and speeds of the fragments, estimate their lifetimes, and obtain additional information on the nucleus shape. Given that we have no access to an adequate national facility, our only chance of continuing this research is by taking advantage of NSF's open skies policy and requesting Gemini time through NOAO.