RESEARCH
<< back
A compositional link between rocky exoplanets and their host stars

V. Zh. Adibekyan, C. Dorn, S. G. Sousa, N. C. Santos, B. Bitsch, G. Israelian, C. Mordasini, S. C. C. Barros, E. Delgado Mena, O. Demangeon, J. P. Faria, P. Figueira, A. A. Hakobyan, M. Oshagh, B. Soares, M. Kunitomo, Y. Takeda, E. Jofré, R. Petrucci, E. Martioli

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.

Notes
Read full article here.

Science
Volume 374, Number 6565, Page 330
2021 October

>> ADS>> DOI

Faculdade de Ciências da Universidade de Lisboa Universidade do Porto Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Fundação para a Ciência e a Tecnologia COMPETE 2020 PORTUGAL 2020 União Europeia