arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1910.00512astro-ph.SR
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HD27463的TESS光变曲线中的旋转和脉动变化

Rotational and pulsational variability in the TESS light curve of HD27463

V. Khalack, C. Lovekin, D. M. Bowman, O. Kobzar, A. David-Uraz, E. Paunzen, J. Sikora, P. Lenz, O. Kochukhov, D. L. Holdsworth, G. A. Wade

摘要:

本文分析了凌日系外行星巡天卫星(\textit{TESS})最近获得的脉动Ap星HD~27463的光度学新资料,以寻找其光度变化。我们的分析表明,HD~27463表现出两种类型的光度变化。周期为$P$ =~2.834274 $\pm$ 0.000008 d的低频变率可以用倾斜磁转子模型和表面丰度/亮斑的存在来解释,而探测到的高频变率则是$δ$ ~Scuti脉动的特征。通过对HD~27463的两个FEROS光谱中可见的巴耳末线轮廓的分析,我们导出了它的有效温度和表面重力,发现这些值与\textit{TESS}输入星表(TIC)中公布的该星的值接近。已知旋转周期和从巴耳末线轮廓的拟合估计的v $\sin{i}$值,我们发现旋转轴以$i=33\pm8°$的角度倾斜于视线。我们的最佳拟合模型的观测到的脉动模式的结果在一个过冲参数值$f_{ov} = 0.014$和全球恒星参数的值,在TIC中报告的数据和来自拟合巴耳末线轮廓的数据吻合得很好。该模型表明年龄为5.0 $\pm$ ~0.4 $\times 10^8$ ~yrs,这对应于核心氢分数为0.33。

英文摘要:

The new photometric data on pulsating Ap star HD~27463 obtained recently with the Transiting Exoplanet Survey Satellite (\textit{TESS}) are analysed to search for variability. Our analysis shows that HD~27463 exhibits two types of photometric variability. The low frequency variability with the period $P$ =~2.834274 $\pm$ 0.000008 d can be explained in terms of axial stellar rotation assuming the oblique magnetic rotator model and presence of surface abundance/brightness spots, while the detected high-frequency variations are characteristics of $δ$~Scuti pulsations. From the analysis of Balmer line profiles visible in two FEROS spectra of HD~27463 we have derived its effective temperature and surface gravity, finding values that are close to those published for this star in the \textit{TESS} Input Catalogue (TIC). Knowing the rotation period and the v$\sin{i}$ value estimated from the fitting of Balmer line profiles we found that the rotational axis is inclined to the line of sight with an angle of $i=33\pm8°$. Our best-fitting model of the observed pulsation modes results in an overshoot parameter value $f_{ov} = 0.014$ and values of global stellar parameters that are in good agreement with the data reported in the TIC and with the data derived from fitting Balmer line profiles. This model indicates an age of 5.0 $\pm$~0.4 $\times 10^8$~yrs, which corresponds to a core hydrogen fraction of 0.33.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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