Lambda Boo Abundance Patterns: Accretion from Orbiting Sources

TL;DR

This paper proposes that lambda Boo stars may acquire their peculiar abundance patterns through accretion of material from the winds of hot Jupiters, offering a new explanation for their anomalies.

Contribution

It introduces a novel hypothesis that hot Jupiter winds could explain lambda Boo star abundance patterns, contrasting with previous interstellar accretion models.

Findings

Radiation pressure may allow selective accretion of certain elements.

Accretion from hot Jupiter winds could account for observed abundance anomalies.

The proposed mechanism does not require dust in the accreted material.

Abstract

The abundance anomalies in lambda Boo stars are popularly explained by element-specific mass inflows at rates that are much greater than empirically-inferred bounds for interstellar accretion. Therefore, a lambda Boo star's thin outer envelope must derive from a companion star, planet, analogs to Kuiper Belt Objects or a circumstellar disk. Because radiation pressure on gas-phase ions might selectively allow the accretion of carbon, nitrogen, and oxygen and inhibit the inflow of elements such as iron, the source of the acquired matter need not contain dust. We propose that at least some lambda Boo stars accrete from the winds of hot Jupiters.