Host-star and exoplanet composition: Polluted white dwarf reveals depletion of moderately refractory elements in planetary material

Fuente: arXiv
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Main Authors: Aguilera-Gómez, Claudia, Rogers, Laura K., Bonsor, Amy, Jofré, Paula, Blouin, Simon, Shorttle, Oliver, Buchan, Andrew M., Li, Yuqi, Xu, Siyi
Format: Preprint
Published: 2024
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author Aguilera-Gómez, Claudia
Rogers, Laura K.
Bonsor, Amy
Jofré, Paula
Blouin, Simon
Shorttle, Oliver
Buchan, Andrew M.
Li, Yuqi
Xu, Siyi
author_facet Aguilera-Gómez, Claudia
Rogers, Laura K.
Bonsor, Amy
Jofré, Paula
Blouin, Simon
Shorttle, Oliver
Buchan, Andrew M.
Li, Yuqi
Xu, Siyi
contents Planets form from the same cloud of molecular gas and dust as their host stars. Confirming if planetary bodies acquire the same refractory element composition as their natal disc during formation, and how efficiently volatile elements are incorporated into growing planets, is key to linking the poorly constrained interior composition of rocky exoplanets to the observationally-constrained composition of their host star. Such comparisons also afford insight into the planet formation process. This work compares planetary composition with host-star composition using observations of a white dwarf that has accreted planetary material and its F-type star wide binary companion as a reference for the composition of the natal molecular gas and dust. Spectroscopic analysis reveals abundances of Fe, Mg, Si, Ca, and Ti in both stars. We use the white dwarf measurements to estimate the composition of the exoplanetary material and the F-type companion to constrain the composition of the material the planet formed from. Comparing planetary material to the composition of its natal cloud, our results reveal that the planetary material is depleted in moderate refractories (Mg, Si, Fe) relative to the refractory material (Ca, Ti). Grouping elements based on their condensation temperatures is key to linking stellar and planetary compositions. Fractionation during formation or subsequent planetary evolution leads to the depletion of moderate refractories from the planetary material accreted by the white dwarf. This signature, as seen for bulk Earth, will likely be present in the composition of many exoplanets relative to their host-stars.
format Preprint
id arxiv_https___arxiv_org_abs_2411_03454
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Host-star and exoplanet composition: Polluted white dwarf reveals depletion of moderately refractory elements in planetary material
Aguilera-Gómez, Claudia
Rogers, Laura K.
Bonsor, Amy
Jofré, Paula
Blouin, Simon
Shorttle, Oliver
Buchan, Andrew M.
Li, Yuqi
Xu, Siyi
Solar and Stellar Astrophysics
Earth and Planetary Astrophysics
Planets form from the same cloud of molecular gas and dust as their host stars. Confirming if planetary bodies acquire the same refractory element composition as their natal disc during formation, and how efficiently volatile elements are incorporated into growing planets, is key to linking the poorly constrained interior composition of rocky exoplanets to the observationally-constrained composition of their host star. Such comparisons also afford insight into the planet formation process. This work compares planetary composition with host-star composition using observations of a white dwarf that has accreted planetary material and its F-type star wide binary companion as a reference for the composition of the natal molecular gas and dust. Spectroscopic analysis reveals abundances of Fe, Mg, Si, Ca, and Ti in both stars. We use the white dwarf measurements to estimate the composition of the exoplanetary material and the F-type companion to constrain the composition of the material the planet formed from. Comparing planetary material to the composition of its natal cloud, our results reveal that the planetary material is depleted in moderate refractories (Mg, Si, Fe) relative to the refractory material (Ca, Ti). Grouping elements based on their condensation temperatures is key to linking stellar and planetary compositions. Fractionation during formation or subsequent planetary evolution leads to the depletion of moderate refractories from the planetary material accreted by the white dwarf. This signature, as seen for bulk Earth, will likely be present in the composition of many exoplanets relative to their host-stars.
title Host-star and exoplanet composition: Polluted white dwarf reveals depletion of moderately refractory elements in planetary material
topic Solar and Stellar Astrophysics
Earth and Planetary Astrophysics
url https://arxiv.org/abs/2411.03454