WASP-44b, WASP-45b and WASP-46b: three short-period, transiting extrasolar planets WASP-44b, WASP-45b and WASP-46b
WASP-44b, WASP-45b and WASP-46b: three short-period, transiting extrasolar planets WASP-44b, WASP-45b and WASP-46b
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WASP-44b、WASP-45b 和 WASP-46b：三颗短周期凌日系外行星 WASP-44b、WASP-45b 和 WASP-46b
DOI：
10.1111/j.1365-2966.2012.20635.x
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发表时间：
2012
影响因子：
4.8
通讯作者：
Anderson D
中科院分区：
文献类型：
--
作者：
Anderson D
我们报告发现了三颗太阳系外行星，它们的宿主恒星中等亮度（mV= 12-13）。WASP-44 b是一颗0.89兆质量的行星，围绕一颗G8 V星星运行2.42天。WASP-45 b是一颗1.03兆质量的行星，每3.13天经过其K2 V宿主星星的边缘。在WASP-45的光谱中看到的微弱的CaiH和K发射表明该星星是色球活跃的。WASP-46 b是一颗2.10兆质量的行星，围绕一颗G6 V星星运行1.43天。WASP-46的光变曲线的旋转调制和光谱中微弱的CaiH &K发射表明该星星是光球和色球活跃的。我们在分析中采用了圆形轨道，因为径向速度数据与（近）圆形轨道一致，这可以从经验和潮汐理论的角度来预期这种短周期，超小行星质量的行星。我们讨论了拟合偏心轨道的行星时，不支持的数据的影响。推导出的行星和恒星半径取决于拟合偏心率和这些参数通知激烈的理论努力，潮汐循环和加热，散装行星组成和观测到的系统误差行星和恒星半径。因此，我们建议在没有证据表明非圆性的情况下，用偏心模型拟合短周期、质量为1000亿颗行星的轨道时要谨慎。
We report the discovery of three extrasolar planets that transit their moderately bright (mV= 12–13) host stars. WASP-44b is a 0.89-MJupplanet in a 2.42-day orbit around a G8V star. WASP-45b is a 1.03-MJupplanet which passes in front of the limb of its K2V host star every 3.13 days. Weak CaiiH&K emission seen in the spectra of WASP-45 suggests that the star is chromospherically active. WASP-46b is a 2.10-MJupplanet in a 1.43-day orbit around a G6V star. Rotational modulation of the light curves of WASP-46 and weak CaiiH&K emission in its spectra show the star to be photospherically and chromospherically active.We imposed circular orbits in our analyses as the radial-velocity data are consistent with (near-)circular orbits, as could be expected from both empirical and tidal-theory perspectives for such short-period, ∼Jupiter-mass planets. We discuss the impact of fitting for eccentric orbits for such planets when not supported by the data. The derived planetary and stellar radii depend on the fitted eccentricity and these parameters inform intense theoretical efforts concerning tidal circularization and heating, bulk planetary composition and the observed systematic errors in planetary and stellar radii. As such, we recommend exercising caution in fitting the orbits of short-period, ∼Jupiter-mass planets with an eccentric model when there is no evidence of non-circularity.