Properties and asteroseismological analysis of a new ZZ ceti discovered by TMTS

作者：Jincheng Guo, Yanhui Chen, Xiaofeng Wang, Jie Lin, Gaobo Xi, Jun Mo, A. V. Filippenko, Thomas G. Brink, Xiao-Yu Ma, Weikai Zong, Yong Yang, Jingkun Zhao, Xiangyun Zeng, Zhihao Chen, Ali Esamdin, Fangzhou Guo, Abdusamatjan Iskandar, Xiaojun Jiang, Wenxiong Li, Cheng Liu, Jianrong Shi, Xuan Song, Letian Wang, Danfeng Xiang, Shengyu Yan, Jicheng Zhang, Yonghui Yang · 发表于：Monthly Notices of the Royal Astronomical Society · 年份：2023 · DOI：10.1093/mnras/stad1545 · 被引用次数：8 · 研究领域：Stellar, planetary, and galactic studies、Astronomy and Astrophysical Research、Gamma-ray bursts and supernovae

ABSTRACT Tsinghua University-Ma Huateng Telescope for Survey (TMTS) aims to discover rapidly evolving transients by monitoring the northern sky. The TMTS catalogue is cross-matched with the white dwarf (WD) catalogue of Gaia EDR3, and light curves of more than a thousand WD candidates are obtained so far. Among them, the WD TMTS J23450729+5813146 is one interesting common source. Based on the light curves from the TMTS and follow-up photometric observations, periods of 967.113, 973.734, 881.525, 843.458, 806.916, and 678.273 s are identified. In addition, the TESS observations suggest a 3.39-h period but this can be attributed to the rotation of a comoving M dwarf located within 3 arcsec. The spectroscopic observation indicates that this WD is DA type with Teff = 11 778 ± 617 K, log g = 8.38 ± 0.31, mass = 0.84 ± 0.20 M⊙, and age = 0.704 ± 0.377 Gyr. Asteroseismological analysis reveals a global best-fitting solution of Teff = 12 110 ± 10 K and mass = 0.760 ± 0.005 M⊙, consistent with the spectral fitting results, and oxygen and carbon abundances in the core centre are 0.73 and 0.27, respectively. The distance derived from the intrinsic luminosity given by asteroseismology is 93 parsec, which is in agreement with the distance of 98 parsec from Gaia DR3. Additionally, kinematic study shows that this WD is likely a thick-disc star. The mass of its zero-age main sequence is estimated to be 3.08 M⊙ and has a main sequence plus cooling age of roughly 900 Myr.