HAT-P-11b: A SUPER-NEPTUNE PLANET TRANSITING A BRIGHT K STAR IN THE KEPLER FIELD
HAT-P-11b: A SUPER-NEPTUNE PLANET TRANSITING A BRIGHT K STAR IN THE KEPLER FIELD
复制标题
DOI：
10.1088/0004-637x/710/2/1724
复制
发表时间：
2010-02-20
影响因子：
4.9
通讯作者：
Sari, P.
中科院分区：
文献类型：
--
作者：
Bakos, G. A.;Torres, G.;Sari, P.
我们报告了HAT-P-11b的发现，这是从地面发现的最小半径的凌日系外行星（TEP），也是迄今为止通过凌日搜索发现的第一颗热海王星。HAT-P-11b围绕明亮（V = 9.587）和富含金属（[Fe/H] = +0.31 +/- 0.05）的K4矮星GSC 03561-02092运行，P = 4.8878162 +/- 0.0000071天，并产生深度为4.2 mma的凌日信号，这是凌日搜索中发现的由确认的行星引起的最浅的信号。我们提出了可用的光度和径向速度（RV）数据的全球分析，这些数据导致恒星和行星参数，同时处理系统变化。这颗行星，像它的近双星gj436b一样，比海王星稍大（17 M-circle +, 3.8 R-circle +），质量M-p = 0.081 +/- 0.009 M-J (25.8 +/- 2.9 M-circle +)，半径R-p = 0.422 +/- 0.014 R-J （4.73 +/- 0.16 R-circle +）。HAT-P-11b在偏心轨道上运行，e = 0.198 +/- 0.046, ω = 355°2 +/- 17°3，引起其母星的反射运动，振幅为11.6 +/- 1.2 ms(-1)，由于其母星的色球活动水平很高，这是一个具有挑战性的探测。我们的星历表为T-c = 2454605.89132 +/- 0.00032 (BJD)，持续时间为0.0957 +/- 0.0012天，次日食历元为2454608.96 +/- 0.15天（BJD）。主恒星的基本恒星参数为M-star = 0.809(-0.027)(+0.020) m -圆点，R-star = 0.752 +/- 0.021 r -圆点，T-eff star = 4780 +/- 50 K。重要的是，HAT-P-11将位于即将到来的开普勒任务的一个探测器上；这将使对行星及其母恒星的详细物理特性进行卓有成效的研究成为可能，其精确度将达到前所未有的水平。我们讨论了凌日光曲线和恒星参数对系统偏心率的一个有趣约束。这对于开普勒磁场中具有低振幅RV变化的偏心TEPs将特别有用。我们还提出了混合分析，这是第一次处理混合凌日热木星模仿凌日热海王星的情况，并证明HAT-P-11b不是这样的混合。
We report on the discovery of HAT-P-11b, the smallest radius transiting extrasolar planet (TEP) discovered from the ground, and the first hot Neptune discovered to date by transit searches. HAT-P-11b orbits the bright (V = 9.587) and metal rich ([Fe/H] = +0.31 +/- 0.05) K4 dwarf star GSC 03561-02092 with P = 4.8878162 +/- 0.0000071 days and produces a transit signal with depth of 4.2 mmag, the shallowest found by transit searches that is due to a confirmed planet. We present a global analysis of the available photometric and radial velocity (RV) data that result in stellar and planetary parameters, with simultaneous treatment of systematic variations. The planet, like its near-twin GJ 436b, is somewhat larger than Neptune (17 M-circle plus, 3.8 R-circle plus) both in mass M-p = 0.081 +/- 0.009 M-J (25.8 +/- 2.9 M-circle plus) and radius R-p = 0.422 +/- 0.014 R-J (4.73 +/- 0.16 R-circle plus). HAT-P-11b orbits in an eccentric orbit with e = 0.198 +/- 0.046 and omega = 355.degrees 2 +/- 17.degrees 3, causing a reflex motion of its parent star with amplitude 11.6 +/- 1.2 ms(-1), a challenging detection due to the high level of chromospheric activity of the parent star. Our ephemeris for the transit events is T-c = 2454605.89132 +/- 0.00032 (BJD), with duration 0.0957 +/- 0.0012 days, and secondary eclipse epoch of 2454608.96 +/- 0.15 days (BJD). The basic stellar parameters of the host star are M-star = 0.809(-0.027)(+0.020) M-circle dot, R-star = 0.752 +/- 0.021 R-circle dot, and T-eff star = 4780 +/- 50 K. Importantly, HAT-P-11 will lie on one of the detectors of the forthcoming Kepler mission; this should make possible fruitful investigations of the detailed physical characteristic of both the planet and its parent star at unprecedented precision. We discuss an interesting constraint on the eccentricity of the system by the transit light curve and stellar parameters. This will be particularly useful for eccentric TEPs with low-amplitude RV variations in Kepler's field. We also present a blend analysis, that for the first time treats the case of a blended transiting hot Jupiter mimicking a transiting hot Neptune, and proves that HAT-P-11b is not such a blend.