Exoplanets & Exomoons

A Quantitative Criterion for Defining Planets

By Keith Cowing
November 16, 2015
Filed under ,
A Quantitative Criterion for Defining Planets

A simple metric can be used to determine whether a planet or exoplanet can clear its orbital zone during a characteristic time scale, such as the lifetime of the host star on the main sequence.

This criterion requires only estimates of star mass, planet mass, and orbital period, making it possible to immediately classify 99% of all known exoplanets. All 8 planets and all classifiable exoplanets satisfy the criterion. This metric may be useful in generalizing and simplifying the definition of a planet.

Jean-Luc Margot
(Submitted on 22 Jul 2015 (v1), last revised 14 Oct 2015 (this version, v4))

Comments: Accepted for publication in the Astronomical Journal; 7 pages, 6 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:1507.06300 [astro-ph.EP] (or arXiv:1507.06300v4 [astro-ph.EP] for this version)
Submission history
From: Jean-Luc Margot
[v1] Wed, 22 Jul 2015 19:59:00 GMT (220kb,D)
[v2] Thu, 30 Jul 2015 16:56:02 GMT (210kb,D)
[v3] Mon, 14 Sep 2015 17:41:22 GMT (221kb,D)
[v4] Wed, 14 Oct 2015 18:55:04 GMT (221kb,D)

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