KIC 8462852: Transit of a Large Comet Family

We investigate the plausibility of a cometary source of the unusual transits observed in the KIC 8462852 light curve. A single comet of similar size to those in our solar system produces a transit depth of the order of 10(-3) lasting less than a day which is much smaller and shorter than the largest dip observed (similar to 20% for similar to 3 days), but a large, closely traveling cluster of comets can fit the observed depths and durations. We find that a series of large comet swarms, with all except one on the same orbit, provides a good fit for the KIC 8462852 data during Quarters 16 and 17, but does not explain the large dip observed during Quarter 8. However, the transit dips only loosely constrain the orbits and can be fit by swarms with periastrons differing by a factor of 10. To reach a transit depth of similar to 0.2, the comets need to be in a close group of similar to 30, if they are similar to 100 km in radius or in a group of similar to 300 if they are similar to 10 km in radius. The total number of comets required to fit all of the dips is similar to 70 similar to 100 km or similar to 700 similar to 10 km comets. A single comet family from a tidally disrupted Ceres-sized progenitor or the start of a Late Heavy Bombardment period explains the last similar to 60 days of the unusual KIC 8462852 light curve.