Surfing the photon noise: New techniques to find low-mass planets around M dwarfs
Surfing the photon noise: New techniques to find low-mass planets around M dwarfs
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驾驭光子噪声：寻找 M 型矮星周围低质量行星的新技术
DOI：
10.1002/asna.201211775
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发表时间：
2013
影响因子：
0.9
通讯作者：
Anglada-Escudé G
中科院分区：
文献类型：
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作者：
Anglada-Escudé G
目前用于探测 M 矮星中低质量行星的精确径向速度技术很快得到了回顾。这包括在光学和近红外区域进行的高分辨率光谱观测。我们讨论的是，考虑到当前的仪器性能，光学 RV 仍然远远领先于其他方法。然而，随着具有红色/近红外功能的新型光谱仪的出现，这种情况可能很快就会改变。我们回顾了一种新开发的方法，用于在稳定的摄谱仪上获得精确的 RV 测量，以及如何将其应用于档案 HARPS 观测。除了更接近光子噪声之外，这种方法还使我们能够识别并滤除与波长相关的噪声源，从而在 G、K、特别是 M 矮星上实现前所未有的精度。我们展示了红色/红外观测对于有效、明确地检测冷光谱类型周围的极低质量行星至关重要。作为示例，我们展示了对巴纳德星的新测量结果，表明该恒星在 4 年的时间跨度内稳定低至 0.9 cm s–1，以及当使用 HARPS 波长范围最红的一半时，与活动指数相关的 RV 信号如何消失。总之，我们提出了新的结果、探测结果，并描述了冷恒星周围行星/多行星丰度的影响。 （© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA，魏因海姆）
The current precision radial velocities techniques to detect low mass planets in M dwarf are quickly reviewed. This includes high resolution spectroscopic observations made both in the optical and in the near infrared. We discuss that, given the current instrumental performance, optical RVs are still far ahead over other approaches. However, this situation might change soon with the advent of new spectrographs with red/nIR capabilities. We review a newly developed method to obtain precision RV measurements on stabilized spectrographs and how it is implemented to archival HARPS observations. In addition to get much closer to the photon noise, this approach allows us to identify and filter out wavelength dependent noise sources achieving unprecedented accuracy on G, K and specially M dwarfs. We show how including red/infrared observations is of paramount importance to efficiently and unambiguously detect very low mass planets around cool spectral types. As examples, we show new measurements on Barnard's star indicating that the star is stable down to 0.9 cm s–1over a time‐span of 4 years and how RV signals correlated with activity indices disappear when using the reddest half of the HARPS wavelength range. To conclude, we present new results, detections and describe the implications in terms of planet/multi‐planet abundances around cool stars. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)