TOI-2119: a transiting brown dwarf orbiting an active M-dwarf from NASA's TESS mission
TOI-2119: a transiting brown dwarf orbiting an active M-dwarf from NASA's TESS mission
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TOI-2119：来自 NASA TESS 任务的一颗凌日棕矮星，围绕一颗活跃的 M 矮星运行
DOI：
10.1093/mnras/stac1666
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发表时间：
2022
影响因子：
4.8
通讯作者：
Carmichael T
中科院分区：
文献类型：
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作者：
Carmichael T
我们报告TOI-2119b的发现，这是一颗凌日褐矮星（BD），它围绕一颗活跃的em -矮星运行，并被它完全遮蔽。利用凌日系外行星巡天卫星任务的光曲线数据和后续的高分辨率多普勒光谱观测，我们发现BD的半径为rb = 1.08±0.03RJ，质量为mb = 64.4±2.3MJ，轨道周期为p = 7.200865±0.00002 d，偏心率为e= 0.337±0.002。主星质量为m - - - = 0.53±0.02M⊙，半径为r - - - = 0.50±0.01R⊙，有效温度为teff = 3621±48K，金属丰度为。TOI-2119b加入了一个新兴的围绕m矮星主星的过境北斗系统，TOI-2119是第九个这样的系统。这些M矮星-褐矮星系统的质量比通常接近q=Mb/M -≈0.1−0.2，这将它们与典型的质量比区分开来，这些质量比是由凌日的亚恒星物体和围绕更大质量恒星运行的巨大系外行星组成的系统。根据这颗恒星对双星的二次日食的性质，我们可以估计出这颗恒星下天体的有效温度为2030±84K，这与恒星演化模型的预测一致。
We report the discovery of TOI-2119b, a transiting brown dwarf (BD) that orbits and is completely eclipsed by an activeM-dwarf star. Using light-curve data from the Transiting Exoplanet Survey Satellite mission and follow-up high-resolution Doppler spectroscopic observations, we find the BD has a radius ofRb= 1.08 ± 0.03RJ, a mass ofMb= 64.4 ± 2.3MJ, an orbital period ofP= 7.200865 ± 0.00002 d, and an eccentricity ofe= 0.337 ± 0.002. The host star has a mass ofM⋆= 0.53 ± 0.02M⊙, a radius ofR⋆= 0.50 ± 0.01R⊙, an effective temperature ofTeff= 3621 ± 48K, and a metallicity of. TOI-2119b joins an emerging population of transiting BDs around M-dwarf host stars, with TOI-2119 being the ninth such system. These M-dwarf–brown dwarf systems typically occupy mass ratios nearq=Mb/M⋆≈ 0.1−0.2, which separates them from the typical mass ratios for systems with transiting substellar objects and giant exoplanets that orbit more massive stars. The nature of the secondary eclipse of the BD by the star enables us to estimate the effective temperature of the substellar object to be 2030 ± 84K, which is consistent with predictions by substellar evolutionary models.