Discovery of Two Pulsating Extremely Low-mass Pre-white Dwarf Candidates in the TESS Eclipsing Binaries

doi:10.3847/1538-4357/ab584c

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	Discovery of Two Pulsating Extremely Low-mass Pre-white Dwarf Candidates in the TESS Eclipsing Binaries
	Wang,Kun 2,3; Zhang,Xiaobin 1; Dai,Min 3
刊名	The Astrophysical Journal
	2020
卷号	888 期号:1
关键词	Eclipsing binary stars White dwarf stars Delta Scuti variable stars
ISSN号	0004-637X
DOI	10.3847/1538-4357/ab584c
英文摘要	Abstract We report the discovery of two new pulsating extremely low-mass pre-white dwarf (pre-ELMV) candidates in the Transiting Exoplanet Survey Satellite (TESS) eclipsing binaries, TIC 149160359 and TIC 416264037. Their light curves show a typical feature of EL CVn-type binaries. The light-curve modeling indicates that they are both detached systems with very low-mass ratios (q???0.1). Based on the photometric solutions, the masses and radii of the two main-sequence primary components are estimated, and those of the secondaries are deduced. The results show that the less-massive components of the two binaries are both probably thermally bloated, pre-ELMVs. Apart from the eclipsing light changes, short-period light variations are clearly shown in their residual light curves. We have made the Fourier analysis of their light-curve residuals with the Period04 program. TIC 149160359 was found to pulsate in 21 independent frequencies, 17 of which are between 21 and 35 day?1 and the others are between 63 and 77 day?1. The Fourier amplitude spectrum of TIC 416264037 also shows two frequency concentration ranges. Out of nine independent frequencies, seven reside within the low-frequency range of 12.5–19.9 day?1. Two pulsating signals, f4?=?122.2698 day?1 and f10?=?112.3603 day?1, were detected in the high-frequency region. These low-frequency signals that are detected on TIC 149160359 and TIC 416264037 are probably due to the intrinsic pulsations of their δ Sct-type primary components. However, the high-frequency signals are likely to come from the pulsations of the pre-ELM WD components. This brings the number of pre-ELMV candidates to 12.
语种	英语
出版者	The American Astronomical Society
WOS记录号	IOP:0004-637X-888-1-AB584C
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/28733]
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, 20A Datun Road, Chaoyang District, Beijing 100012, People's Republic of China 2.Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife, Spain 3.Department of Astronomy, China West Normal University, 1 Shida Road, Shunqing District, Nanchong 637002, People's Republic of China; kwang@bao.ac.cn
推荐引用方式 GB/T 7714	Wang,Kun,Zhang,Xiaobin,Dai,Min. Discovery of Two Pulsating Extremely Low-mass Pre-white Dwarf Candidates in the TESS Eclipsing Binaries[J]. The Astrophysical Journal,2020,888(1).
APA	Wang,Kun,Zhang,Xiaobin,&Dai,Min.(2020).Discovery of Two Pulsating Extremely Low-mass Pre-white Dwarf Candidates in the TESS Eclipsing Binaries.The Astrophysical Journal,888(1).
MLA	Wang,Kun,et al."Discovery of Two Pulsating Extremely Low-mass Pre-white Dwarf Candidates in the TESS Eclipsing Binaries".The Astrophysical Journal 888.1(2020).