KIC 8462852's Unusual Light Curve is From a Large Comet Family

KIC 8462852: Transit of a Large Comet Family

Authors:

Bodman et al

Abstract:

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 transit dips of order 10−3 having a duration of less than a day which are much smaller and shorter than the largest dip observed (∼20% for ∼3 days) but a large (greater than 10), closely traveling cluster of comets can fit the observed depths and durations. We find that a series of large comet clusters with all but one on the same orbit provides a good fit for the KIC 8462852 data during Quarters 16 and 17 but not the large dip observed during Quarter 8. However, the transit dips only loosely constrain the orbits and can be fit by clusters with periastrons differing by an order of magnitude. To reach a transit depth of ∼0.2, the comets need to be in a close group of ∼30 if ∼100 km in radius or in a group of ∼300 if ∼10 km. The total number of comets required to fit all the dips is 73 ∼100 km or 731 ∼10 km comets. A single comet family from a large completely disrupted progenitor explains the last ∼60 days of the unusual KIC 8462852 light curve.