A Simple Analytical Model for Rocky Planet Interiors

作者：Zeng Li; Jacobsen Stein B

来源：Astrophysical Journal, 2017, 837(2): 164.

DOI：10.3847/1538-4357/aa6218

• Earth
• planets and satellites: composition
• planets and satellites: fundamental parameters
• planets and satellites: interiors
• planets and satellites: terrestrial planets

This work aims to explore the scaling relations among rocky exoplanets. The assumption that the internal gravity increases linearly in the core and stays constant in the mantle is tested against numerical simulations, and a simple model is constructed, applicable to rocky exoplanets of CMF (core mass fraction) = 0.2-0.35 and mass = 0.1-30 M.. Various scaling relations are derived: (1) CMF approximate to CRF2 (core radius fraction squared), (2) P-typical similar to g(s)(2) (typical interior pressure scales as surface gravity squared), (3) energy released in core formation is similar to 1/10 the total gravitational energy, (4) effective heat capacity of the mantle approximate to (M-p/M(empty set)) x 7.5 x 10(27) J K-1, ( 5) moment of inertia approximate to 1/3M(p)R(p)(2). These relations, though approximate, are handy for quick use owing to their simplicity and lucidity, and provide insights into the interior structures of those exoplanets.

• 出版日期2017-3-10