文章基本信息

标题：A Second Terrestrial Planet Orbiting the Nearby M Dwarf LHS 1140
本地全文：下载
作者：Kristo Ment ; Jason A. Dittmann ; Nicola Astudillo-Defru 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2019
卷号：157
期号：1
页码：1-13
DOI：10.3847/1538-3881/aaf1b1
语种：English
出版社：American Institute of Physics
摘要：LHS 1140 is a nearby mid-M dwarf known to host a temperate rocky super-Earth (LHS 1140 b) on a 24.737-day orbit. Based on photometric observations by MEarth and Spitzer as well as Doppler spectroscopy from the High Accuracy Radial velocity Planet Searcher, we report the discovery of an additional transiting rocky companion (LHS 1140 c) with a mass of 1.81±0.39M ⊕ and a radius of 1.282±0.024 R ⊕ on a tighter, 3.77795-day orbit. We also obtain more precise estimates for the mass and radius of LHS 1140 b, which are 6.98±0.89 M ⊕ and 1.727±0.032 R ⊕ . The mean densities of planets b and c are 7.5±1.0 gcm −3 and 4.7±1.1 gcm −3 , respectively, both consistent with the Earth’s ratio of iron to magnesium silicate. The orbital eccentricities of LHS 1140 b and c are consistent with circular orbits and constrained to be below 0.06 and 0.31, respectively, with 90% confidence. Because the orbits of the two planets are coplanar and because we know from previous analyses of Kepler data that compact systems of small planets orbiting M dwarfs are commonplace, a search for more transiting planets in the LHS 1140 system could be fruitful. LHS 1140 c is one of the few known nearby terrestrial planets whose atmosphere could be studied with the upcoming James Webb Space Telescope.
关键词：planets and satellites: detection;planets and satellites: terrestrial planets;techniques: photometric;techniques: radial velocities