RedDots: a temperate 1.5 Earth-mass planet candidate in a compact multiterrestrial planet system around GJ 1061
RedDots: a temperate 1.5 Earth-mass planet candidate in a compact multiterrestrial planet system around GJ 1061
复制标题
DOI：
10.1093/mnras/staa248
复制
发表时间：
2020-03-01
影响因子：
4.8
通讯作者：
Anglada-Escude, G.
中科院分区：
文献类型：
--
作者：
Dreizler, S.;Jeffers, S., V;Anglada-Escude, G.
小的低质量恒星是探测岩石宜居行星的有利目标。特别是，在太阳附近的行星系统是有趣的，适合于精确的表征。RedDots活动旨在发现围绕附近低质量恒星运行的岩石行星。2018年的活动针对的是GJ 1061，这是距离太阳最近的第20颗星星。连续三个月，我们获得了夜间，高精度的径向速度测量与HARPS摄谱仪。我们分析了这些数据与档案HARPS数据。我们报告了三颗候选行星的探测结果，它们的周期分别为3.204 +/- 0.001、6.689 +/- 0.005和13.03 +/- 0.03 d，接近于1：2：4的周期比。在考虑了噪声和采样的性质之后，我们得出结论，第四个信号最有可能是由恒星旋转解释的，尽管它可能是由于行星。提出的三行星系统（以及潜在的四行星解决方案）是长期动态稳定的。行星与行星之间的引力相互作用低于我们目前的探测阈值。这三颗行星的最小质量范围为1.4 +/- 0.2至1.8 +/- 0.3 M-圈。行星d的msin i = 1.64 +/- 0.24 M-circle plus，接收到的能量与地球从太阳接收到的能量相似。因此，它位于星星的液态水适居带内，并且具有与地球相似的平衡温度。GJ 1061的性质与比邻星非常相似，但活动指数表明恒星活动水平较低。
Small low-mass stars are favourable targets for the detection of rocky habitable planets. In particular, planetary systems in the solar neighbourhood are interesting and suitable for precise characterization. The RedDots campaigns seek to discover rocky planets orbiting nearby low-mass stars. The 2018 campaign targeted GJ 1061, which is the 20th nearest star to the Sun. For three consecutive months we obtained nightly, high-precision radial velocity measurements with the HARPS spectrograph. We analysed these data together with archival HARPS data. We report the detection of three planet candidates with periods of 3.204 +/- 0.001, 6.689 +/- 0.005, and 13.03 +/- 0.03 d, which are close to 1:2:4 period commensurability. After several considerations related to the properties of the noise and sampling, we conclude that a fourth signal is most likely explained by stellar rotation, although it may be due to a planet. The proposed three-planet system (and the potential four-planet solution) is long-term dynamically stable. Planet-planet gravitational interactions are below our current detection threshold. The minimum masses of the three planets range from 1.4 +/- 0.2 to 1.8 +/- 0.3 M-circle plus. Planet d, with msin i = 1.64 +/- 0.24 M-circle plus, receives a similar amount of energy as Earth receives from the Sun. Consequently it lies within the liquid-water habitable zone of the star and has a similar equilibrium temperature to Earth. GJ 1061 has very similar properties to Proxima Centauri but activity indices point to lower levels of stellar activity.