Asteroseismic Analyses of Slowly Pulsating B Star KIC 8324482: Ultraweak Element Mixing beyond the Central Convective Core

Author:

Wu TaoORCID,Li YanORCID,Deng Zhen-min,Lin Gui-fangORCID,Song Han-fengORCID,Jiang ChenORCID

Abstract

Abstract Asteroseismology is a powerful tool for probing the inner structure and determining the evolutionary status and the fundamental parameters of stars. The oscillation spectra of slowly pulsating B (SPB) stars show almost uniform period spans, whose pattern is sensitive to the structure of the μ-gradient shell beyond the central convective core and hence can be used to efficiently describe their shapes and constrain the convective core. The SPB star KIC 8324482 was observed by Kepler for over 1470 days with a long-cadence pattern. Nearly equidistant period spacing patterns are found for the 14 connective dipolar modes that are extracted from the oscillation spectrum by Zhang et al. In the present work, we analyze them in depth with the χ 2-matching method and determine their χ 2-minimization models (CMMs). Based on those calculated CMMs, we find that KIC 8324482 is a young ( Myr), metal-poor ( dex), and intermediate-mass ( ) star with a convective core of in mass and in radius and with a surface rotation velocity . The central hydrogen abundance is of . Asteroseismic analyses indicate that the “propagation time” of g-mode in KIC 8324482 is of μHz. To well match with the observed period spacing pattern, an extra diffusion mixing ( ) should be considered, but the normal core overshooting f ov must be fixed as zero in the best-fitting model. Such ultraweak mixing beyond the convective core corresponds to a fast rotation that is about 20–30 times the asteroseismic suggested rotation Ωrot ≃ 0.2 μHz, if it is thought of as shear mixing induced completely by differential rotation.

Funder

NSFC of China

Yunnan Applied Basic Research Projects

B-type Strategic Priority Program of the Chinese Academy of Sciences

Publisher

American Astronomical Society

Subject

Space and Planetary Science,Astronomy and Astrophysics

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