Program: GN-2017B-Q-69

Centaurs reside on unstable orbits between Jupiter and Neptune, and are regarded as transition objects between their source in the Kuiper Belt (KB) and Jupiter family comets (JFCs). About 10% of the population shows comet-like activity even far beyond the orbit of Jupiter, the source of which is not yet fully understood. Jewitt (2009) proposed that crystallization of amorphous ice could be the process driving observed mass loss, because they are too cold for the sublimation of water ice, and too hot to retain large supplies of supervolatiles. Only a limited sample of active Centaurs have been studied so far (Jewitt 2009, 2015, Mazzotta Epifani et al. 2017), and the results suggest an apparent lack of activity beyond R~13 AU, which is the farthest distance for the crystallization of amorphous ice as calculated by Jewitt (2009). We propose to use the Gemini North telescope to search for activity in 15 Centaurs discovered by the Pan-STARRS survey in order to investigate whether this theory is valid, i.e., whether there are no active Centaurs beyond 13 AU.