A Quantitative Criterion for Defining Planets

Abstract

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.

Accepted for publication in the Astronomical Journal; 7 pages, 6 figures

References in corpus (5)

• The Mass-Radius Relation for 65 Exoplanets Smaller than 4 Earth Radii
• Advances in exoplanet science from Kepler
• Planetary chaotic zone clearing: destinations and timescales
• What is a planet?
• The Potato Radius: a Lower Minimum Size for Dwarf Planets

Cited by in corpus (7)

• The Planet Nine Hypothesis
• Solar System Physics for Exoplanet Research
• The IAU Working Definition of an Exoplanet
• Towards a Classification Scheme for the Rocky Planets based on Equilibrium Thermodynamic Considerations
• Takeout and Delivery: Erasing the Dusty Signature of Late-stage Terrestrial Planet Formation
• Quantitative Criteria for Defining Planets
• Long-term Dynamical Stability in the Outer Solar System I: The Regular and Chaotic Evolution of the 34 Largest Trans-Neptunian Objects