A compositional link between rocky exoplanets and their host stars
Abstract
Stars and planets both form by accreting material from a surrounding disk. Because they grow from the same material, theory predicts that there should be a relationship between their compositions. In this study, we search for a compositional link between rocky exoplanets and their host stars. We estimate the iron-mass fraction of rocky exoplanets from their masses and radii and compare it with the compositions of their host stars, which we assume reflect the compositions of the protoplanetary disks. We find a correlation (but not a 1:1 relationship) between these two quantities, with a slope of >4, which we interpret as being attributable to planet formation processes. Super-Earths and super-Mercuries appear to be distinct populations with differing compositions, implying differences in their formation processes.
Cite
@article{arxiv.2102.12444,
title = {A compositional link between rocky exoplanets and their host stars},
author = {Vardan Adibekyan and Caroline Dorn and Sérgio G. Sousa and Nuno C. Santos and Bertram Bitsch and Garik Israelian and Christoph Mordasini and Susana C. C. Barros and Elisa Delgado Mena and Olivier D. S. Demangeon and João P. Faria and Pedro Figueira and Artur A. Hakobyan and Mahmoudreza Oshagh and Barbara M. T. B. Soares and Masanobu Kunitomo and Yoichi Takeda and Emiliano Jofré and Romina Petrucci and Eder Martioli},
journal= {arXiv preprint arXiv:2102.12444},
year = {2021}
}
Comments
Authors' version of the manuscript. Published in Science