Solar-like oscillations in accreting pre-main sequence stars: Insights and prospects

TL;DR

This paper provides theoretical predictions for solar-like oscillations in accreting pre-main sequence stars, exploring how accretion influences their internal structures and oscillation frequencies, with implications for future observations by the ESA PLATO mission.

Contribution

It introduces detailed evolutionary models of accreting pre-main sequence stars and analyzes the impact of accretion on their oscillation properties, which is a novel approach.

Findings

Characteristic frequencies > 500 μHz in models

Accretion affects buoyancy and Lamb profiles

Frequency differences up to 20 μHz across accretion histories

Abstract

We present theoretical predictions for solar-like oscillators in the pre-main sequence phase of stellar evolution. Our pre-main sequence models start from a stellar seed of 0.01 solar masses that gains mass through accretion, offering an alternative description to the classical approach segmented into the Hayashi and Henyey tracks. Evolutionary models are calculated using the \mesa stellar evolution code with a custom accretion routine and pulsation properties are investigated using the \GYRE oscillation code. We present evolutionary tracks and internal structures for accreting pre-main sequence solar-like stars in the mass range from 0.7 to 1.6 solar masses, adopting 35 mass accretion histories previously extracted from two-dimensional magneto-hydrodynamical simulations. Atmospheric parameters of our models constrain characteristic frequencies of pre-main sequence solar-like oscillators to be generally greater than 500 $\mu\text{Hz}$. We highlight the imprint of accretion on the buoyancy and Lamb profiles and illustrate the effects on the small- and large frequency separations. We additionally quantify individual frequency differences across the 35 accretion histories at the zero-age main-sequence, showcasing differences no larger than $20 \ \mu\text{Hz}$ for an exemplary model. Finally, we discuss the potential of detecting solar-like oscillations in pre-main sequence stars with the upcoming ESA PLATO mission.