论文标题
用苔丝观察到脉动缺乏氢的白色矮人和白色矮人 - iv。发现两个新的GW Vir Star：TIC0403800675和TIC1989122424
Pulsating hydrogen-deficient white dwarfs and pre-white dwarfs observed with TESS -- IV. Discovery of two new GW Vir stars: TIC0403800675 and TIC1989122424
论文作者
论文摘要
我们提出了两个新的GW纯型白矮星星，TIC \，0403800675（WD \，J115727.68-280349.64）和TIC \，1989122424（WD J211738.38.38-552801.18） 数据。对于这两颗恒星，苔丝光曲线揭示了振荡的存在，周期为400至410 \ s的周期，这与典型的重力（$ g $） - 模式相关。后续地面光谱法表明，这两颗恒星具有相似的有效温度（$ t_ \ mathrm {eff} = 110,000 \ pm 10,000 $ \，k）和表面引力（$ \ log G = 7.5 \ pm 0.5 $），但He/c组成（质量分数）不同TIC \，0403800675，He \，= \，0.50和C \，= \，0.50，用于TIC \，1989122424。通过对其光谱能量分布进行拟合，我们发现了$ r = 0.019 \ pm0.002 \，r_ \ odot $和$ \ log（l/l_ \ odot）= 1.68^{+0.15} _ {+0.15} _ { - 0.24} $。通过采用PG〜1159星的进化轨道，我们发现这两颗星的质量均为$ 0.56 \ pm0.18 m _ {\ odot} $，来自$ \ log g $ g $ - $ t_ \ $ t_ \ mathrm {eff} $ {eff} $图，$ 0.60^{+0.11} $ 0.11} $ 0.11} $ _ { - 0.09} m__罗素图。
We present two new GW Vir-type pulsating white dwarf stars, TIC\,0403800675 (WD\,J115727.68-280349.64) and TIC\,1989122424 (WD J211738.38-552801.18) discovered in the Transiting Exoplanet Survey Satellite (TESS) photometric data. For both stars, the TESS light curves reveal the presence of oscillations with periods in a narrow range between 400 and 410\,s, which are associated with typical gravity ($g$)-modes. Follow-up ground-based spectroscopy shows that both stars have similar effective temperature ($T_\mathrm{eff} = 110,000 \pm 10,000$\,K) and surface gravity ($\log g = 7.5 \pm 0.5$), but different He/C composition (mass fractions): He\,=\,0.75 and C\,=\,0.25 for TIC\,0403800675, and He\,=\,0.50 and C\,=\,0.50 for TIC\,1989122424. By performing a fit to their spectral energy distributions, we found for both stars radii and luminosities of $R=0.019\pm0.002\,R_\odot$ and $\log(L/L_\odot)=1.68^{+0.15}_{-0.24}$, respectively. By employing evolutionary tracks of PG~1159 stars, we find the masses of both stars to be $0.56\pm0.18 M_{\odot}$ from the $\log g$-$T_\mathrm{eff}$ diagram and $0.60^{+0.11}_{-0.09} M_{\odot}$ from the Hertzsprung Russell diagram.
