Modelling δ Scuti pulsations: a new grid of p, g, and f modes across pre-main-sequence to post-main-sequence evolution
ABSTRACT Space-based photometry reveals regular high-frequency patterns in many young $\delta$ Scuti stars. These pulsations provide a powerful means of inferring stellar properties, particularly ages, for young $\delta$ Scuti stars for which traditional age-dating methods are poorly constrained. Realizing this potential requires theoretical models that capture the complexities of stellar structure and evolution. We present a comprehensive grid of 25 million stellar pulsation models, computed using the mesa stellar evolution code and the gyre stellar oscillation code, tailored to $\delta$ Scuti stars. The grid spans a wide range of masses, metallicities, and rotation velocities, and covers evolutionary phases from the early pre-main-sequence through the main sequence (MS) and into the post-main-sequence contraction phase. For each model, we computed adiabatic pulsation frequencies for degrees $\ell = 0$–3, capturing p modes, g modes, f modes, and their interactions through avoided crossings. We find that f and low-order g modes have mode inertias comparable to or lower than the fundamental radial mode during the late pre-MS and early MS, implying that these modes should be observable. We revisit $\delta$ Scuti scaling relations and map asteroseismic observables, including the large frequency separation ($\Delta \nu$) and phase offset parameter ($\varepsilon$), across age, mass, metallicity, and rotation. This new model grid, which is publicly available, improves upon previous such model grids by facilitating interpretation of $\delta$ Scuti pulsations, allowing for more reliable age estimates and tighter constraints on stellar evolutionary pathways, and planet formation in A- and F-type stars.
Authors
- T. R. Bedding (ORCID: https://orcid.org/0000-0001-5222-4661)
- Simon J Murphy
- Anuj Gatuam
Institutions
- The University of Sydney (AU)
- University of Southern Queensland (AU)
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society
- Published
- 2025-11-12
- DOI
- https://doi.org/10.1093/mnras/staf2001
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 0.00