2023/07/12 by James S. Kuszlewicz, Marc Hon, Kuszlewicz, James S. +3 · 1 citation
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy and Astrophysical Research #FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR) #Stellar, planetary, and galactic studies
paper · pdf · doi:10.48550/arxiv.2307.06482
openalex publication_date 2023/07/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present measurements of the dipole mode asymptotic period spacing (ΔΠ1), the coupling factor between p- and g- modes (q), the g-mode phase offset (εg), and the mixed-mode frequency rotational splitting (δνrot) for 1,074 low-luminosity red giants from the Kepler mission. Using oscillation mode frequencies extracted from each star, we apply Bayesian optimization to estimate ΔΠ1 from the power spectrum of the stretched period spectrum and to perform the subsequent forward modelling of the mixed-mode frequencies. With our measurements, we show that the mode coupling factor q shows significant anti-correlation with both stellar mass and metallicity, and can reveal highly metal-poor stars. We present the evolution of εg up the lower giant branch up to before the luminosity bump, and find no significant trends in εg or δνrot with stellar mass and metallicity in our sample. Additionally, we identify six new red giants showing anomalous distortions in their g-mode pattern. Our data products, code, and results are provided in a public repository.