Modeling stellar abundance patterns resulting from the addition of earthlike planetary material

TL;DR

This paper models how adding Earth-like planetary material to a star's convection zone affects its observed stellar abundance patterns, aiding interpretation of chemical signatures related to exoplanetary systems.

Contribution

It introduces a quantitative model for differential stellar abundances resulting from accretion of Earth-like material, considering variable convection zone masses and composition effects.

Findings

Differential abundances depend on the amount of accreted material.

The model accounts for convection zone mass variability.

Volatility and condensation temperature influence abundance patterns.

Abstract

The literature on precision differential abundances (PDAs) in stars is extensive. Surveys include sun-like stars in the solar neighborhood, binary systems, and Galactic clusters. Numerous references as well as a discussion of relevant mechanisms may be found in papers by Ramirez, et al. (2019) and Nagar, et al. (2020). A strong impetus for this work is the probability that the abundances have been influenced by exoplanetary systems and their evolution. We calculate the resulting differential abundances ([El/H]) assuming a given amount of material with the composition of the bulk earth (Wang, et al. 2018) was added to the stellar convection zone of a dwarf G-type star. The mass of the convection zone is uncertain and variable, depending on the spectral type. Here, we assume a mass of $5\cdot 10^{31}$ gm for the stellar convection zone (SCZ). This is 0.025 $M_\odot$ (Pinsonneault, et al. 2001, Chambers, 2010). For other SCZ masses, the parameters must be adjusted accordingly. In general, the sunlike star will not have exactly the solar composition. This contingency is roughly taken into account in our model. An appendix discusses issues of volatility and condensation temperature.