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On the Fate of Interstellar Objects Captured by our Solar System

Napier, Kevin J. and Adams, Fred C. and Batygin, Konstantin (2021) On the Fate of Interstellar Objects Captured by our Solar System. Planetary Science Journal, 2 (6). Art. No. 217. ISSN 2632-3338. doi:10.3847/PSJ/ac29bb.

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With the recent discoveries of interstellar objects `Oumuamua and Borisov traversing the solar system, understanding the dynamics of interstellar objects is more pressing than ever. These detections have highlighted the possibility that captured interstellar material could be trapped in our solar system. The first step in rigorously investigating this question is to calculate a capture cross section for interstellar objects as a function of hyperbolic excess velocity, which can be convolved with any velocity dispersion to compute a capture rate (Napier et. al. 2021). Although the cross section provides the first step toward calculating the mass of alien rocks residing in our solar system, we also need to know the lifetime of captured objects. We use an ensemble of N-body simulations to characterize a dynamical lifetime for captured interstellar objects and determines the fraction of surviving objects as a function of time (since capture). We also illuminate the primary effects driving their secular evolution. Finally, we use the resulting dynamical lifetime function to estimate the current inventory of captured interstellar material in the solar system. We find that capture from the field yields a steady state mass of only ∼10⁻¹³ M_⊕, whereas the mass remaining from capture events in the birth cluster is roughly 10⁻⁹ M_⊕.

Item Type:Article
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URLURL TypeDescription Paper
Napier, Kevin J.0000-0003-4827-5049
Adams, Fred C.0000-0002-8167-1767
Batygin, Konstantin0000-0002-7094-7908
Additional Information:© 2021. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2021 August 3; revised 2021 September 13; accepted 2021 September 22; published 2021 November 1. We thank two anonymous referees for providing useful feedback. This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. NNX17AF21G issued through the SSO Planetary Astronomy Program and by the National Science Foundation under Grant No. AST-2009096.
Funding AgencyGrant Number
Subject Keywords:Solar system (1528), Dynamical evolution (421), Small solar system bodies (1469), Kuiper belt (893), Oort cloud (1157)
Issue or Number:6
Classification Code:Unified Astronomy Thesaurus concepts: Solar system (1528); Dynamical evolution (421); Small Solar System bodies (1469); Interstellar objects (52); Kuiper belt (893); Oort cloud (1157)
Record Number:CaltechAUTHORS:20211018-185317459
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Official Citation:Kevin J Napier et al 2021 Planet. Sci. J. 2 217
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:111534
Deposited By: George Porter
Deposited On:03 Nov 2021 19:48
Last Modified:03 Nov 2021 20:59

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