Status Report

Probabilistic Constraints on the Mass and Composition of Proxima b

By SpaceRef Editor
February 8, 2017
Filed under ,

Alex Bixel, Dániel Apai
(Submitted on 8 Feb 2017)

Recent studies regarding the habitability, observability, and possible orbital evolution of the indirectly detected exoplanet Proxima b have mostly assumed a planet with M∼1.3 M⊕, a rocky composition, and an Earth-like atmosphere or none at all. In order to assess these assumptions, we use previous studies of the radii, masses, and compositions of super-Earth exoplanets to probabilistically constrain the mass and radius of Proxima b, assuming an isotropic inclination probability distribution. We find it is ~90% likely that the planet’s density is consistent with a rocky composition; conversely, it is at least 10% likely that the planet has a significant amount of ice or an H/He envelope. If the planet does have a rocky composition, then we find expectation values and 95% confidence intervals of ⟨M⟩rocky=1.63+1.66−0.72 M⊕ for its mass and ⟨R⟩rocky=1.07+0.38−0.31 R⊕ for its radius.

Comments:    6 pages, 3 figures, 1 table. Accepted for publication in ApJL
Subjects:    Earth and Planetary Astrophysics (astro-ph.EP)
Cite as:    arXiv:1702.02542 [astro-ph.EP] (or arXiv:1702.02542v1 [astro-ph.EP] for this version)
Submission history
From: Alex Bixel
[v1] Wed, 8 Feb 2017 17:52:53 GMT (321kb,D)

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