论文标题
未分辨磁点对高精度径向速度测量的影响
The impact of unresolved magnetic spots on high precision radial velocity measurements
论文作者
论文摘要
外球星的多普勒方法非常成功，但遭受了恒星活动的噪声污染。在这项工作中，提出了带有磁场的旋转恒星模型，该模型基于K2星Epsilon Eridani的几何形状，并用于估计其对模拟径向速度测量值的影响。在观察到的八年的光谱观测中获得的大规模磁图的顶部模拟了许多不同分布的未解决磁场。由于磁场而引起的径向速度信号的幅度最高为10 m s $^{ - 1} $，足够高以防止在太阳能恒星的温带区域中检测到20个地球质量以下的行星。我们表明径向速度在很大程度上取决于点分布。我们的结果强调，了解恒星磁活动和斑点分布对于检测地球类似物至关重要。
The Doppler method of exoplanet detection has been extremely successful, but suffers from contaminating noise from stellar activity. In this work a model of a rotating star with a magnetic field based on the geometry of the K2 star Epsilon Eridani is presented and used to estimate its effect on simulated radial velocity measurements. A number of different distributions of unresolved magnetic spots were simulated on top of the observed large-scale magnetic maps obtained from eight years of spectropolarimetric observations. The radial velocity signals due to the magnetic spots have amplitudes of up to 10 m s$^{-1}$, high enough to prevent the detection of planets under 20 Earth masses in temperate zones of solar type stars. We show that the radial velocity depends heavily on spot distribution. Our results emphasize that understanding stellar magnetic activity and spot distribution is crucial for detection of Earth analogues.
