Did Kepler-444 have a long-lived convective core?

Author:

Winther Mark Lykke1ORCID,Aguirre Børsen-Koch Víctor2,Rørsted Jakob Lysgaard1ORCID,Stokholm Amalie341ORCID,Verma Kuldeep15ORCID

Affiliation:

1. Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University , Ny Munkegade 120, DK-8000 Aarhus C , Denmark

2. DARK, Niels Bohr Institute, University of Copenhagen , Jagtvej 128, DK-2200 Copenhagen , Denmark

3. Dipartimento di Fisica e Astronomia, Università degli Studi di Bologna , Via Gobetti 93/2, I-40129 Bologna , Italy

4. INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna , Via Gobetti 93/3, I-40129 Bologna , Italy

5. Department of Physics, Indian Institute of Technology (BHU) , Varanasi 221005 , India

Abstract

ABSTRACT With the greater power to infer the state of stellar interiors provided by asteroseismology, it has become possible to study the survival of initially convective cores within stars during their main-sequence evolution. Standard theories of stellar evolution predict that convective cores in subsolar mass stars have lifetimes below $1\, {\rm Gyr}$. However, a recent asteroseismic study of the star Kepler-444 concluded that the initial convective core had survived for nearly $8\, {\rm Gyr}$. The goal of this paper is to study the convective-core evolution of Kepler-444 and to investigate its proposed longevity. We modify the input physics of stellar models to induce longer convective-core lifetimes and vary the associated parameter across a dense grid of evolutionary tracks. The observations of metallicity, effective temperature, mean density, and asteroseismic frequency ratios are fitted to the models using the basta pipeline. We explore different choices of constraints, from which a long convective-core lifetime is only recovered for a few specific combinations: mainly from the inclusion of potentially unreliable frequencies and/or excluding the covariances between the frequency ratios, whereas for the classical parameters, the derived luminosity has the largest influence. For all choices of observables, our analysis reliably constrains the convective-core lifetime of Kepler-444 to be short, with a median around $0.6\, {\rm Gyr}$ and a 1σ upper bound around $3.5\, {\rm Gyr}$.

Funder

Carlsberg Foundation

Danish National Research Foundation

European Research Council

European Space Agency

Publisher

Oxford University Press (OUP)

Subject

Space and Planetary Science,Astronomy and Astrophysics

Cited by 1 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

1. A grid of 200 000 models of young δ Scuti stars using mesa and GYRE;Monthly Notices of the Royal Astronomical Society;2023-09-25

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3