That's the way the comet crumbles: Splitting Jupiter-family comets

摘要

Our current understanding of split, Jupiter-family comets is reviewed. Thefocus is on what recent studies of comets have told us about the nature of thesplitting phenomenon. The goal is to not repeat the information given in recentreviews of split comets, but to build upon it. In particular, we discuss cometsthat have suffered splitting or fragmentation events in the past few years.These include comets (a) 57P/du Toit-Neujmin-Delporte, observed with a longtrain of fragments in 2002; (b) 73P/Schwassmann-Wachmann 3, which split in 1995and was extensively studied during its relatively close passage to Earth in2006, during which dozens of fragments were discovered and studied; and (c)174P/Echeclus, a Centaur and potentially future JFC, which split in late 2005and was the first such Centaur observed to do so. We also discuss recentobservations by SOHO of split comets that are likely of short-period. TheSpitzer Space Telescope has observed many JFCs and provided us withunprecedented detailed views of cometary debris trails, which may be thought ofas a middle ground between "normal" ejection of micron-sized dust grains andthe cleaving off of meter-to-kilometer sized fragments. We will also discusspotential breakthroughs in studying splitting JFCs that may come from futuresurveys.