A PLANETARY SYSTEM AROUND THE NEARBY M DWARF GJ 667C WITH AT LEAST ONE SUPER-EARTH IN ITS HABITABLE ZONE
A PLANETARY SYSTEM AROUND THE NEARBY M DWARF GJ 667C WITH AT LEAST ONE SUPER-EARTH IN ITS HABITABLE ZONE
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DOI：
10.1088/2041-8205/751/1/l16
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发表时间：
2012-05-20
影响因子：
7.9
通讯作者：
Jenkins, James S.
中科院分区：
文献类型：
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作者：
Anglada-Escude, Guillem;Arriagada, Pamela;Jenkins, James S.
我们重新分析了附近M1.5矮星GJ 667 C的4年HARPS光谱，这些光谱可通过欧洲南方天文台公共档案获得。新的径向速度（RV）的测量获得了使用一种新的数据分析技术，推导出多普勒测量和其他仪器的影响，使用最小二乘法。将这些新的143个测量结果与来自麦哲伦/行星巡天光谱仪和凯克/高分辨率中阶梯光谱仪光谱仪的41个额外的RV相结合，揭示了先前报道的7.2天候选者之外的三个额外信号，周期为28天，75天，以及与气体巨星存在一致的长期趋势（周期类似于10年）。28天的信号意味着一颗最小质量为4.5M的行星候选者。在星星的液态水适居带（HZ）的规范定义范围内运行，也就是说，在星星周围的区域，类地行星可以在其表面维持液态水。尽管如此，这个候选者的最终水支持能力取决于未知的属性，如它的大气组成，大气成分和内部动力学。75天的信号不太确定，受到潜在的91天信号之间的混叠相互作用的显著影响，以及在两个活动指数中检测到的星星的可能旋转周期为105天。GJ 667 C是GJ 667 AB的共同自行伴星，与太阳相比，GJ 667 AB是贫金属的。在一个三重星星系统中，一个贫金属M矮星的HZ中存在一个超级地球，这支持了这样的世界在银河系中应该无处不在的证据。
We re-analyze 4 years of HARPS spectra of the nearby M1.5 dwarf GJ 667C available through the European Southern Observatory public archive. The new radial velocity (RV) measurements were obtained using a new data analysis technique that derives the Doppler measurement and other instrumental effects using a least-squares approach. Combining these new 143 measurements with 41 additional RVs from the Magellan/Planet Finder Spectrograph and Keck/High Resolution Echelle Spectrometer spectrometers reveals three additional signals beyond the previously reported 7.2 day candidate, with periods of 28 days, 75 days, and a secular trend consistent with the presence of a gas giant (period similar to 10 years). The 28 day signal implies a planet candidate with a minimum mass of 4.5M. orbiting well within the canonical definition of the star's liquid water habitable zone (HZ), that is, the region around the star at which an Earth-like planet could sustain liquid water on its surface. Still, the ultimate water supporting capability of this candidate depends on properties that are unknown such as its albedo, atmospheric composition, and interior dynamics. The 75 day signal is less certain, being significantly affected by aliasing interactions among a potential 91 day signal, and the likely rotation period of the star at 105 days detected in two activity indices. GJ 667C is the common proper motion companion to the GJ 667AB binary, which is metal-poor compared to the Sun. The presence of a super-Earth in the HZ of a metal-poor M dwarf in a triple star system supports the evidence that such worlds should be ubiquitous in the Galaxy.