Composition of super-Earths, super-Mercuries, and their host stars

Adibekyan, V.; Santos, N. C.; Dorn, C.; Sousa, S. G.; Hakobyan, A. A.; Bitsch, B.; Mordasini, Ch.; Barros, S. C. C.; Delgado Mena, E.; Demangeon, O. D. S.; Faria, J. P.; Figueira, P.; Soares, B. M. T. B.; Israelian, G.
Referencia bibliográfica

Communications of the Byurakan Astrophysical Observatory

Fecha de publicación:
12
2021
Número de autores
14
Número de autores del IAC
1
Número de citas
5
Número de citas referidas
4
Descripción
Because of their common origin, it was assumed that the composition of planet building blocks should, to a first order, correlate with stellar atmospheric composition, especially for refractory elements. In fact, information on the relative abundance of refractory and major rock-forming elements such as Fe, Mg, Si has been commonly used to improve interior estimates for terrestrial planets. Recently Adibekyan et al. (2021) presented evidence of a tight chemical link between rocky planets and their host stars. In this study we add six recently discovered exoplanets to the sample of Adibekyan et al and re-evaluate their findings in light of these new data. We confirm that i) iron-mass fraction of rocky exoplanets correlates (but not a 1:1 relationship) with the composition of their host stars, ii) on average the iron-mass fraction of planets is higher than that of the primordial f star iron, iii) super-Mercuries are formed in disks with high iron content. Based on these results we conclude that disk-chemistry and planet formation processes play an important role in the composition, formation, and evolution of super-Earths and super-Mercuries.