Radial velocity confirmation of K2-100b: a young, highly irradiated, and low-density transiting hot Neptune
Radial velocity confirmation of K2-100b: a young, highly irradiated, and low-density transiting hot Neptune
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DOI：
10.1093/mnras/stz2569
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发表时间：
2019-11-01
影响因子：
4.8
通讯作者：
Tamura, M.
中科院分区：
文献类型：
--
作者：
Barragan, O.;Aigrain, S.;Tamura, M.
本文详细分析了K2-100的HARPS-N径向速度观测结果。K2-100是Praesepe星系团中一颗年轻活跃的星星，它拥有一颗周期为1.7 d的凌日行星。我们用多维高斯过程框架模拟了主星星的活动引起的径向速度变化，并检测到一个10.6 +/- 3.0 m s（-1）的行星信号，这与凌日星历相匹配，并转换为21.8 +/- 6.2 M-圆加的行星质量。我们执行一系列验证测试，以确认我们检测到的信号是真实的。这是第一次对年轻疏散星团中的凌日行星进行质量测量。这颗行星的密度相对较低，为2.04（-0.61）（+0.66）g cm（-3），这意味着K2- 100 b保持着一个显著的挥发性包层。我们估计这颗行星正在以10（11）-10（12）g s（-1）的速度失去大气层，这是由于它从其宿主星星接收到的高水平辐射。
We present a detailed analysis of HARPS-N radial velocity observations of K2-100, a young and active star in the Praesepe cluster, which hosts a transiting planet with a period of 1.7 d. We model the activity-induced radial velocity variations of the host star with a multidimensional Gaussian Process framework and detect a planetary signal of 10.6 +/- 3.0 m s(-1), which matches the transit ephemeris, and translates to a planet mass of 21.8 +/- 6.2 M-circle plus. We perform a suite of validation tests to confirm that our detected signal is genuine. This is the first mass measurement for a transiting planet in a young open cluster. The relatively low density of the planet, 2.04(-0.61)(+0.66) g cm(-3), implies that K2-100b retains a significant volatile envelope. We estimate that the planet is losing its atmosphere at a rate of 10(11)-10(12) g s(-1) due to the high level of radiation it receives from its host star.