Peculiar Comets Ejected Early In Solar System Formation

Abstract

<p>Comet C/2016 R2 PanSTARRS presents an unusually high N<sub>2</sub>/CO abundance ratio, as well as a heavy depletion in H<sub>2</sub>O, making it the only known comet to have this composition. Two studies have independently estimated the possible origin of this comet from building blocks formed in a peculiar region in the protoplanetary disk, near the ice line of CO and N<sub>2</sub>. Here we explore the potential fates of comets formed from these building blocks using a numerical simulation of early solar system formation and tracking the dynamics of these objects in the Jumping Neptune scenario. We find that objects formed in the region of the CO- and N<sub>2</sub>- icelines a are highly likely to be sent towards the Oort Cloud or ejected from the Solar System altogether on a relatively short timescale, thus offering a potential explanation for the scarcity of comets with R2’s unique composition.  </p>