Is it possible to detect planets around young active G and K dwarfs
Is it possible to detect planets around young active G and K dwarfs
复制标题
是否有可能探测到年轻活跃的 G 矮星和 K 矮星周围的行星
DOI：
10.1093/mnras/stt1950
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发表时间：
2014
影响因子：
4.8
通讯作者：
H. R. A
中科院分区：
文献类型：
--
作者：
Jeffers;Barnes;H. R. A
理论预测表明，行星在非常年轻的恒星中的分布可能与在Gyr旧系统中观察到的典型分布非常不同，Gyr旧系统是目前径向速度测量的重点。然而，与年轻恒星相关的恒星活动增加阻碍了对年轻恒星周围行星的探测，这些恒星的特征可能会对行星的探测产生偏差。在这篇文章中，我们对探测年轻活跃的G和K矮星周围的行星的可能性施加了现实的限制。基于G矮星HD 141943和K1矮星AB Dor的断层成像的恒星活动模型也包括了斑块和许多小的随机恒星黑子的贡献。我们的结果表明，年轻的太阳型恒星上恒星活动水平的增加强烈地影响了对地球质量和木星质量行星的探测，活动抖动的程度与恒星活动的程度直接相关。我们还表明，对于G矮星和K矮星，作为光谱类型的函数，单个恒星的活动分布比诱导径向速度的差异更重要。我们的结论是，在快速旋转的年轻活跃恒星周围可以近距离探测到木星质量的行星，在中等自转恒星周围可以探测到海王星质量的行星，而超级地球只能在旋转速度很慢的恒星周围探测到。通过观察年轻恒星而增加的恒星活动抖动的影响，可以通过将观测基线延长到至少100个纪元来补偿。
Theoretical predictions suggest that the distribution of planets in very young stars could be very different to that typically observed in Gyr old systems that are the current focus of radial velocity surveys. However, the detection of planets around young stars is hampered by the increased stellar activity associated with young stars, the signatures of which can bias the detection of planets. In this paper, we place realistic limitations on the possibilities for detecting planets around young active G and K dwarfs. The models of stellar activity based on tomographic imaging of the G dwarf HD 141943 and the K1 dwarf AB Dor also include contributions from plage and many small random starspots. Our results show that the increased stellar activity levels present on young solar-type stars strongly impacts the detection of Earth-mass and Jupiter-mass planets and that the degree of activity jitter is directly correlated with stellarvsini. We also show that for G and K dwarfs, the distribution of activity in individual stars is more important than the differences in induced radial velocities as a function of spectral type. We conclude that Jupiter-mass planets can be detected close-in around fast-rotating young active stars, Neptune-mass planets around moderate rotators and that Super-Earths are only detectable around very slowly rotating stars. The effects of an increase in stellar activity jitter by observing younger stars can be compensated for by extending the observational base-line to at least 100 epochs.