THE ORBITAL PHASES AND SECONDARY TRANSITS OF KEPLER-10b. A PHYSICAL INTERPRETATION BASED ON THE LAVA-OCEAN PLANET MODEL
THE ORBITAL PHASES AND SECONDARY TRANSITS OF KEPLER-10b. A PHYSICAL INTERPRETATION BASED ON THE LAVA-OCEAN PLANET MODEL
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KEPLER-10b 的轨道相位和二次凌星。
DOI：
10.1088/2041-8205/741/2/l30
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
Alain L'eger
中科院分区：
文献类型：
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作者：
D. Rouan;H. Deeg;O. Demangeon;B. Samuel;C. Cavarroc;B. Fegley;Alain L'eger
开普勒使命进行了一项重要的观测：通过观测类地行星的相位曲线（开普勒-10 b），首次探测到来自类地行星的光子。这为系外行星科学开辟了一个新的领域：获得有关岩石行星的大气和表面信息的可能性，这是人们最感兴趣的物体。在这封信中，我们应用Lava海洋模型来解释观测到的相位曲线。该模型是一个没有大气层和部分由熔融岩石组成的行星，已被提出用于CoRoT-7 b类行星，即，非常接近它们的星星（在几个恒星半径处）的岩石行星。开普勒-10b是这个家族的典型成员。它预测，来自行星的光除了反射的光之外，还有一个重要的发射成分，即使在开普勒光谱带中也是如此。假设行星表面的光的各向同性反射（类朗伯近似），我们发现，一个0.50%的邦德反射率可以解释所观察到的相位曲线的振幅，而不是第一次尝试，一个异常高的值被发现。未来可以用詹姆斯·韦伯太空望远镜或系外行星表征天文台等仪器对整体解释进行测试。我们的模型预测的光谱依赖性，这是明显区别于纯反射光，从一个行星在一个统一的温度。
The Kepler mission has made an important observation: the first detection of photons from a terrestrial planet by observing its phase curve (Kepler-10b). This opens a new field in exoplanet science: the possibility of obtaining information about the atmosphere and surface of rocky planets, objects of prime interest. In this Letter, we apply the Lava-ocean model to interpret the observed phase curve. The model, a planet without atmosphere and a surface partially made of molten rocks, has been proposed for planets of the class of CoRoT-7b, i.e., rocky planets very close to their star (at a few stellar radii). Kepler-10b is a typical member of this family. It predicts that the light from the planet has an important emission component in addition to the reflected one, even in the Kepler spectral band. Assuming an isotropical reflection of light by the planetary surface (Lambertian-like approximation), we find that a Bond albedo of ∼50% can account for the observed amplitude of the phase curve, as opposed to a first attempt where an unusually high value was found. We propose a physical process to explain this still large value of the albedo. The overall interpretation can be tested in the future with instruments such as the James Webb Space Telescope or the Exoplanet Characterization Observatory. Our model predicts a spectral dependence that is clearly distinguishable from that of purely reflected light and from that of a planet at a uniform temperature.