Discovery and Seismic Analysis of an EL CVn-type Binary with Hybrid δ Sct-γ Dor Pulsations

doi:10.3847/1538-4357/ab3fa9

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	Discovery and Seismic Analysis of an EL CVn-type Binary with Hybrid δ Sct-γ Dor Pulsations
	Zhang,X. B.1; Wang,K.2; Chen,X. H.3; Luo,C. Q.1; Zhang,C. G.1
刊名	The Astrophysical Journal
	2019-10-20
卷号	884 期号:2
关键词	asteroseismology binaries: eclipsing stars: individual (KIC 8113154)
ISSN号	0004-637X
DOI	10.3847/1538-4357/ab3fa9
英文摘要	Abstract We report the discovery of an EL CVn-type binary consisting of a low-mass, pre-helium white dwarf and the first detection of hybrid δ Sct-γ Dor pulsations in such binary systems. Based on the four years Kepler data, we determined comprehensive photometric solution of the eclipsing binary KIC 8113154. The light-curve modeling reveals that it is a detached system containing a thermally bloated, low-mass, pre-He white dwarf with the mass of 0.26?±?0.02 M⊙ and the radius of 0.13?±?0.01 R⊙. After removal of the binary model from the observed Kepler data, multiple frequency analysis is applied to the light residuals. The Fourier spectrum shows low-order p-modes and high-order g-mode pulsations that very likely stem from the F-type primary component star, which could be classified as a new δ Sct-γ Dor hybrid. We detected 111 frequencies with signal-to-noise amplitude ratios larger than 4.0. From these frequencies, we identified 17 high-order quadrupole (l?=?2) g modes, including eight zonal (m?=?0) and nine prograde (m?=?2) ones, on the basis of which we derived the asymptotic period spacing of the g modes and the internal rotation rate of the convective core. This is significantly smaller than the orbital frequency, indicating that the core and envelope of the primary star in KIC 8113154 rotate differentially.
语种	英语
出版者	The American Astronomical Society
WOS记录号	IOP:0004-637X-884-2-AB3FA9
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/28425]
专题	中国科学院国家天文台
作者单位	1.Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, People’s Republic of China xzhang@bao.ac.cn 2.Department of Astronomy, China West Normal University, Nanchong 637002, People’s Republic of China 3.Yunnan Observatories, Chinese Academy of Sciences, P.O. Box 110, Kunming 650216, People’s Republic of China
推荐引用方式 GB/T 7714	Zhang,X. B.,Wang,K.,Chen,X. H.,et al. Discovery and Seismic Analysis of an EL CVn-type Binary with Hybrid δ Sct-γ Dor Pulsations[J]. The Astrophysical Journal,2019,884(2).
APA	Zhang,X. B.,Wang,K.,Chen,X. H.,Luo,C. Q.,&Zhang,C. G..(2019).Discovery and Seismic Analysis of an EL CVn-type Binary with Hybrid δ Sct-γ Dor Pulsations.The Astrophysical Journal,884(2).
MLA	Zhang,X. B.,et al."Discovery and Seismic Analysis of an EL CVn-type Binary with Hybrid δ Sct-γ Dor Pulsations".The Astrophysical Journal 884.2(2019).