A Catalog of Exoplanets with Equilibrium Temperature less than 600 K

David G. Russell

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arXiv · 2303.06214

A Catalog of Exoplanets with Equilibrium Temperature less than 600 K

David G. Russell

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Abstract

The NASA Exoplanet Archive was searched for planets with an equilibrium temperature below 600 K, mass uncertainty less than 27 percent, and radius uncertainty less than 8 percent. This search produced 93 planets with mass from 0.3 to 1680 ME; and 101 planets if the Solar System planets are included. The characteristics of the sample in this catalog are: (1) 94 percent of the Terrestrial planets have mass less than 2.9 ME and radius less than 1.4 RE, (3) The sample has a small drop in population consistent with the previously identified radius gap from 1.5 to 2.0 RE, (4) Planets in the radius range 1.50 to 2.25 RE are consistent with either a gas-rich Terrestrial composition or a rock-ice Terrestrial composition with a supercritical hydrosphere and water mass fraction less than 20 percent, (5) A super-Neptune radius desert is observed for the radius range 4.5 to 7.5 RE, (6) Saturn composition planets have masses from 15 to 170 ME and radii from 7.9 to 10.1 RE, (7) A nearly barren sub-Saturn mass-radius desert is found in the sample as indicated by a lack of planets with mass exceeding 20 ME and radii in the range 4.0 to 7.5 RE, (8) Most Jupiter composition planets have radii between 10.9 and 12.4 RE and mass exceeding 200 ME, (9) With few exceptions, planet radius can be used as a proxy for planet composition classification into Terrestrial, gas-rich Terrestrial or supercritical hydrosphere Terrestrial, Rock-Ice Giant, and Gas Giant composition classes for this sample of Teq less than 600 K planets. The characteristics of this sample are consistent with several predictions of the core accretion model including the predicted values for the critical core mass for gas accretion and runaway accretion, the pebble isolation mass, and the Saturn mass desert.

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David G. Russell. 2023-03-10. A Catalog of Exoplanets with Equilibrium Temperature less than 600 K. https://arxiv.org/abs/2303.06214

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