Activity and magnetic field structure of the Sun-like planet-hosting star HD 1237
Activity and magnetic field structure of the Sun-like planet-hosting star HD 1237
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类太阳行星主恒星 HD 1237 的活动和磁场结构
DOI：
10.1051/0004-6361/201525771
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发表时间：
2015
影响因子：
6.5
通讯作者：
Alvarado-Gómez J
中科院分区：
文献类型：
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作者：
Alvarado-Gómez J
我们利用HARPS光谱偏振时间序列数据分析了类太阳恒星HD 1237的磁活动特征。我们发现磁场纵向测量的旋转调制的证据与我们的ZDI分析一致，为期7天。我们研究了根据观测光谱的线深定制LSD掩模的效果，发现它对提取的stokesv轮廓的形状影响很小，但确实导致S/N的小幅增加（~7%）。我们发现用Milne-Eddington解来描述局域线轮廓可以更好地拟合这颗慢旋转恒星的LSD轮廓，这也影响了恢复的ZDI场分布。我们还引入了基于ZDI地图解集信息含量（熵）的拟合停止准则。恢复的磁场图显示出一个强（+90 G）的环形方位场分布和一个复杂的径向场在中纬度（~45度）占主导地位。从相隔5个月的数据中恢复了类似的磁场图。未来的工作将研究这种表面磁场分布如何影响这颗行星宿主恒星周围的日冕磁场和扩展环境。
We analyse the magnetic activity characteristics of the planet-hosting Sun-like star, HD 1237, using HARPS spectro-polarimetric time-series data. We find evidence of rotational modulation of the magnetic longitudinal field measurements that is consistent with our ZDI analysis with a period of 7 days. We investigate the effect of customising the LSD mask to the line depths of the observed spectrum and find that it has a minimal effect on the shape of the extracted StokesVprofile but does result in a small increase in the S/N (~7%). We find that using a Milne-Eddington solution to describe the local line profile provides a better fit to the LSD profiles in this slowly rotating star, which also affects the recovered ZDI field distribution. We also introduce a fit-stopping criterion based on the information content (entropy) of the ZDI map solution set. The recovered magnetic field maps show a strong (+90 G) ring-like azimuthal field distribution and a complex radial field dominating at mid latitudes (~45 degrees). Similar magnetic field maps are recovered from data acquired five months apart. Future work will investigate how this surface magnetic field distribution affeccts the coronal magnetic field and extended environment around this planet-hosting star.