HD 46375：年轻太阳的地震和光谱偏振分析，拥有一颗类似土星的行星
HD 46375: seismic and spectropolarimetric analysis of a young Sun hosting a Saturn-like planet
摘要：
HD 46375是一颗类似土星的系外行星，距离主星0.04天文单位。在2008年11月获得的34天CoRoT运行中初步确定了行星反射的星光。我们约束的磁场的HD 46375的光谱偏振观测与NARVAL光谱仪在Pic du Midi天文台的基础上的属性。此外，我们还利用高分辨率的NARVAL通量谱来控制大气参数。有了这些限制，我们执行的HD 46375使用从CoRoT光变曲线提取的频率的asteroseisic分析和建模。我们使用塞曼多普勒成像来重建恒星表面的磁图。在光谱分析中，我们使用一维LTE大气模型拟合孤立线。该分析用于限制恒星的有效温度，表面重力和化学成分。为了提取关于p模式振荡的信息，我们使用了基于包络自相关函数（EACF）的技术。从塞曼多普勒成像观测，我们观察到一个磁场~5高斯。根据光谱分析，HD 46375是一颗未演化的K 0型恒星，金属丰度[Fe/H]=+0.39。由于恒星相对较暗（m_hip=8.05），信噪比太低，无法识别单个模式。然而，我们测量到p模式过剩功率和大分离Δ nu_0=153.0 +/-0.7 muHz。由于光谱和地震分析，我们能够限制恒星的基本参数。我们得出结论，HD 46375类似于Alpha-CenB的年轻版本。这项工作具有特殊意义，因为它结合了系外行星科学和星震学，而这两个学科是目前开普勒任务和拟议的PLATO任务的主题。
英文摘要：
HD 46375 is known to host a Saturn-like exoplanet orbiting at 0.04 AU from its host star. Stellar light reflected by the planet was tentatively identified in the 34-day CoRoT run acquired in October-November 2008. We constrain the properties of the magnetic field of HD 46375 based on spectropolarimetric observations with the NARVAL spectrograph at the Pic du Midi observatory. In addition, we use a high-resolution NARVAL flux spectrum to contrain the atmospheric parameters. With these constraints, we perform an asteroseismic analysis and modelling of HD 46375 using the frequencies extracted from the CoRoT light curve. We used Zeeman Doppler imaging to reconstruct the magnetic map of the stellar surface. In the spectroscopic analysis we fitted isolated lines using 1D LTE atmosphere models. This analysis was used to constrain the effective temperature, surface gravity, and chemical composition of the star. To extract information about the p-mode oscillations, we used a technique based on the envelope autocorrelation function (EACF). From the Zeeman Doppler imaging observations, we observe a magnetic field of ~5 gauss. From the spectral analysis, HD 46375 is inferred to be an unevolved K0 type star with high metallicity [Fe/H]=+0.39. Owing to the relative faintness of the star (m_hip=8.05), the signal-to-noise ratio is too low to identify individual modes. However, we measure the p-mode excess power and large separation Delta nu_0=153.0 +/- 0.7 muHz. We are able do constrain the fundamental parameters of the star thanks to spectrometric and seismic analyses. We conclude that HD 46375 is similar to a young version of Alpha-CenB. This work is of special interest because of its combination of exoplanetary science and asteroseismology, which are the subjects of the current Kepler mission and the proposed PLATO mission.
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。
