Asteroseismology of the High-amplitude δ Scuti Star EH Librae
7 affiliations
- 1Beijing Normal University
- 2Chinese Academy of Sciences
- 3Universidad Nacional Autónoma de México
- 4Taiyuan Normal University
- 5China West Normal University
- 6International Centre of Supernovae
- 7School of Physics, Nankai University, Tianjin 300071,
Abstract
A subclass of intermediate mass variables δ Scuti stars, known as high-amplitude δ Scuti (HADS) stars, exhibits pronounced radial pulsations. We used ground- and space-based observations to perform an asteroseismic analysis of the HADS star EH Lib. Following the reduction of light curves, the frequency analysis reveals the dominant frequency as f ₀ = 11.3105 d ⁻¹ and two newly detected significant frequencies f ₁ and f ₂ , in addition to the harmonics of f ₀ and a linear combination. The period change rate is determined as (1/ P ₀ )( dP ₀ / dt ) = (5.4 ± 0.5) × 10 ⁻⁹ yr ⁻¹ derived from an O − C diagram, which is constructed from 342 times of maximum light spanning over 70 yr. Using these observational constraints, along with the metallicities reported in the literature, we construct theoretical models using the stellar evolution code MESA and calculate the theoretical frequencies of the eigenmodes using the oscillation code GYRE. The appropriate models are selected by matching f ₀ , (1/ P ₀ )( dP ₀ / dt ), and luminosity within their respective uncertainties. The results indicate that the observed period change of EHLib can be attributed to stellar evolutionary effects. The stellar parameters of EHLib are derived as the mass of 1.555 ± 0.015 M ⊙ , the luminosity of log ( L / L ⊙ ) = 1.26 ± 0.02 , and the age of (1.46 ± 0.05) × 10 ⁹ yr. EH Lib is classified as a single-radial-mode HADS star, located in the subgiant branch, with a helium core and hydrogen-burning shell. This work expands the asteroseismological sample of HADS stars and establishes a foundation for future investigations into their commonalities and specific properties, thereby advancing our understanding of these variables.
Related
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- TESS Observations of Seven Newly Identified High-amplitude δ Scuti Stars
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BibTeX
@article{xie2026asteroseismology,
title = {{Asteroseismology of the High-amplitude δ Scuti Star EH Librae}},
author = {Xiran Xie and Jianning Fu and Gang Meng and Lester Fox Machado and Raúl Michel and Huifang Xue and Nian Liu and Zhongyang Liu and Jie Su and Mingfeng Qin},
journal = {The Astrophysical Journal},
year = {2026},
month = oct,
doi = {10.3847/1538-4357/aea6c5},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/aea6c5},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Asteroseismology of the High-amplitude δ Scuti Star EH Librae
AU - Xiran Xie
AU - Jianning Fu
AU - Gang Meng
AU - Lester Fox Machado
AU - Raúl Michel
AU - Huifang Xue
AU - Nian Liu
AU - Zhongyang Liu
AU - Jie Su
AU - Mingfeng Qin
PY - 2026
DA - 2026/10/21
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/aea6c5
UR - https://iopscience.iop.org/article/10.3847/1538-4357/aea6c5
AB - A subclass of intermediate mass variables δ Scuti stars, known as high-amplitude δ Scuti (HADS) stars, exhibits pronounced radial pulsations. We used ground- and space-based observations to perform an asteroseismic analysis of the HADS star EH Lib. Following the reduction of light curves, the frequency analysis reveals the dominant frequency as f ₀ = 11.3105 d ⁻¹ and two newly detected significant frequencies f ₁ and f ₂ , in addition to the harmonics of f ₀ and a linear combination. The period change rate is determined as (1/ P ₀ )( dP ₀ / dt ) = (5.4 ± 0.5) × 10 ⁻⁹ yr ⁻¹ derived from an O − C diagram, which is constructed from 342 times of maximum light spanning over 70 yr. Using these observational constraints, along with the metallicities reported in the literature, we construct theoretical models using the stellar evolution code MESA and calculate the theoretical frequencies of the eigenmodes using the oscillation code GYRE. The appropriate models are selected by matching f ₀ , (1/ P ₀ )( dP ₀ / dt ), and luminosity within their respective uncertainties. The results indicate that the observed period change of EHLib can be attributed to stellar evolutionary effects. The stellar parameters of EHLib are derived as the mass of 1.555 ± 0.015 M ⊙ , the luminosity of log ( L / L ⊙ ) = 1.26 ± 0.02 , and the age of (1.46 ± 0.05) × 10 ⁹ yr. EH Lib is classified as a single-radial-mode HADS star, located in the subgiant branch, with a helium core and hydrogen-burning shell. This work expands the asteroseismological sample of HADS stars and establishes a foundation for future investigations into their commonalities and specific properties, thereby advancing our understanding of these variables.
SN - 0004-637X
SN - 1538-4357
ER -