Exploiting tidal asteroseismology in binary populations from combined space photometry and time-resolved high-resolution spectroscopy

TL;DR

The paper addresses exploiting tidal asteroseismology in binary populations by combining space-based photometry with time-resolved high-resolution spectroscopy to constrain fundamental stellar and binary physics. It notes that space photometry has increased the detection of pulsating stars in binaries by more than four orders of magnitude ($>10^4$), underscoring the need for phase-resolved spectroscopy to test close-binary asteroseismic models. It advocates a unified modelling framework that simultaneously fits light curves, radial velocities, and line-profile variations, supported by spectral synthesis of both binary components, and calls for a large-scale population-level survey enabled by a dedicated multi-object spectrograph with $R \ge 50{,}000$, $\mathrm{S/N} \ge 300$, and $m_V \approx 15$. The work outlines key open science questions for the 2040s and emphasizes the potential to rigorously test models of stellar structure, rotation, mixing, and binary evolution. It also highlights the need for robust data pipelines and standards to ensure long-term accessibility and interoperability of the results.

Abstract

Space-based photometry has substantially increased the number of pulsating stars found in binary systems by more than four orders of magnitude. Combined with high-resolution spectroscopy, high-precision photometry offers model-independent constraints on stellar parameters and internal processes. The advent of space-based photometric surveys has given us access to populations of tidally perturbed pulsators, which offer a unique and demanding set of constraints on tidal physics and stellar interiors. However, we lack the ability to undertake multi-epoch, high-resolution spectroscopy at large scale. The ability to obtain phase-resolved, high-resolution spectra would allow us to place precise, model-independent constraints on the stellar properties of pulsators in binary systems that will truly test our close binary asteroseismic modelling techniques, leading to much-needed constraints on fundamental stellar and binary physics. The need to properly cover the large parameter-space of binary stars demands a large-scale, population-level analysis in order to understand the complex landscape of binary stellar evolution. To enable this population-level analysis, we need a dedicated multi-fibre spectrograph (30--200 fibres) with high spectral resolution ($R\geq 50000$), high signal-to-noise ratio ($\mathrm{S/N\geq 300}$), and a limiting magnitude of approximately 15. Such a spectrograph would be capable of efficiently resolving the pulsation variability on the order of minutes and orbit motion on the order of days to years for many targets.

Figures (1)

• Figure : Illustrative schematic of a close binary system with pulsating stellar components (pulsation modes: $l=2,\,m=0$ and $l=4,\,m=2$). Credit: J. Vandersnickt