The Planet around 51 Pegasi
The Planet around 51 Pegasi
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飞马座 51 周围的行星
DOI：
10.1086/304088
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
G. Jernigan
中科院分区：
文献类型：
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作者：
Geoffrey W. R. Paul;L. Bildsten;J. Graham;A. Ghez;G. Jernigan
从1995年10月到1996年8月对飞马座51进行了多普勒测量，精度为5米/秒。我们发现其周期为4.231天，速度振幅为56±1米/秒，速度曲线基本呈正弦曲线，所有这些都与马约尔和奎洛兹的结果高度吻合。唯一合理的解释是存在一个伴星，其最小质量$m\sin i = 0.45$倍木星质量，位于半径为0.051天文单位的圆形轨道上，偏心率小于0.01。涉及恒星表面现象（如脉动或黑子）的其他解释都被排除。恒星缺乏潮汐加速这一现象限制了伴星质量小于15倍木星质量。如果行星的潮汐Q值小于约$10^6$（接近木星的假定值），那么内部耗散足以使轨道圆形化并使行星自转同步。在减去最佳拟合的开普勒速度曲线后，在10个月期间，残差在5米/秒的水平上没有明显变化。没有进一步的反射运动，再加上红外散斑观测的限制，排除了在质量和轨道半径的大部分参数空间中存在其他伴星的可能性，包括在2.0天文单位内所有大于1倍木星质量的情况。
Doppler measurements of 51 Pegasi have been made from 1995 October through 1996 August, with a precision of 5 m s-1. We find a period of 4.231 days, a velocity amplitude of 56 ± 1 m s-1, and a velocity curve that is essentially sinusoidal, all in excellent agreement with Mayor & Queloz. The only viable interpretation is a companion having minimum mass, m sin i = 0.45 MJupiter, in a circular orbit of radius of 0.051 AU, with an eccentricity less than 0.01. Alternative explanations involving stellar surface phenomena such as pulsation or spots are ruled out. The lack of tidal spin-up of the star constrains the mass of the companion to be less than 15 MJupiter. If the tidal Q-value is less than ~106 for the planet (close to Jupiter's presumed value), then internal dissipation is adequate to circularize the orbit and synchronize the planet's rotation. After subtracting the best-fit Keplerian velocity curve, the residuals exhibit no apparent variations at a level of 5 m s-1 during 10 months. The absence of further reflex motion along with limits from IR speckle observations rule out additional companions in a large portion of the parameter space of mass and orbital radius, including all masses greater than 1 MJupiter within 2.0 AU.