Exocomets in the 47 UMa System: Theoretical Simulations Including Water Transport

Abstract

Motivated by ongoing discoveries of features (most likely) attributable to exocomets in various systems, this study examines the dynamics of possible comets around 47 UMa. Based on the assumption that most systems hosting planets should also harbor leftovers from planet formation processes, comets are thus also expected to exist in the system of 47 UMa. This system is known to host three Jupiter-type planets; however, based on stability analyses, additional terrestrial planets in stable orbits might also be able to exist, including planets in 47 UMa's habitable zone. Furthermore, we also consider a possible 'Hilda'-planet. The aim of our study is to explore the interaction of exocomets with the Jupiter-type planets in the system and examine the probability of cometary collisions with the planets, including possible Earth-mass planets located in the habitable zone. Moreover, we investigate the transport of water onto the Earth-mass planets, including quantitative estimates. It is found that the Earth-mass planets would be able to receive some water, but much less than currently present on Earth. We also checked if the comets form families, but no families were found. Finally, the capture of comets in close orbits and the possibility of small clouds formed when comets come too close to the star and disintegrate are also part of our work.

Water transport throughout the TRAPPIST-1 system: the role of planetesimals

“…However, in the latter scenario, the water on some TRAPPIST-1 planets would likely be lost due to an XUV emission from Ultra Cold Dwarf star (Bolmont et al 2017) through whole lifetime of planetary system. Still, water on them could be delivered after disk phase, at even later stages of evolution of the planetary system, during impacts of planetesimals originating outside of the snow line, thus containing volatile materials (Kral et al 2018;Cuntz, Loibnegger & Dvorak 2018).…”

On the dynamics of comets in extrasolar planetary systems

“…Comets which plunge into the system in the plane of the planetary orbits are also more likely to experience orbitchanging encounters caused by one of the planets. Further results have been given by Cuntz et al [2018].…”

Are there long‐living Hilda‐like asteroids between Jupiter and Saturn?

“…For reasons of comparison, we also tested the difference of the results from a model I to a dynamical model II where we included all four big planets of the outer Solar System. As an integrator, we used the Lie‐integrator, a method with an adaptive step‐size which we used in many of our investigations (e.g., Dvorak et al 2010; Dvorak et al 2017; Cuntz et al 2018; Dvorak et al 2019). A detailed description is given in the original papers by Hanslmeier & Dvorak (1984), Lichtenegger (1984) and Delva (1985), and especially Eggl & Dvorak (2010) where the method is also compared to other ones.…”