Detection of titanium oxide in the atmosphere of a hot Jupiter
Detection of titanium oxide in the atmosphere of a hot Jupiter
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DOI：
10.1038/nature23651
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发表时间：
2017-09
期刊：
影响因子：
64.8
通讯作者：
E. Sedaghati;H. Boffin;R. MacDonald;S. Gandhi;N. Madhusudhan;N. Gibson;M. Oshagh;A. Claret;H. Rauer
中科院分区：
文献类型：
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作者：
E. Sedaghati;H. Boffin;R. MacDonald;S. Gandhi;N. Madhusudhan;N. Gibson;M. Oshagh;A. Claret;H. Rauer
当一颗系外行星经过它的宿主星星时，来自星星的一些光被行星大气中的原子和分子吸收，导致行星看起来更大;绘制行星的观测尺寸作为光波长的函数，产生透射光谱。测量透射光谱的微小变化，再加上大气建模，就可以为系外行星大气的性质提供线索。由轻元素组成的化学物质，如氢、氧、碳、钠和钾，已经以这种方式在几个热的巨型系外行星的大气中被探测到，但由重元素组成的分子迄今为止被证明是难以捉摸的。尽管如此，已经预测，金属氧化物，如氧化钛（TiO）和氧化钒，出现在非常热的系外行星大气的可观测区域，导致昼侧的热反转。在这里，我们报告了在热木星行星WASP-19 b的大气中检测到TiO。我们的组合光谱具有广泛的光谱覆盖范围，揭示了TiO的存在（置信水平为7.7σ），强烈散射的烟雾（7.4σ）和钠（3.4σ），并证实了大气中存在水（7.9σ）。
As an exoplanet transits its host star, some of the light from the star is absorbed by the atoms and molecules in the planet’s atmosphere, causing the planet to seem bigger; plotting the planet’s observed size as a function of the wavelength of the light produces a transmission spectrum. Measuring the tiny variations in the transmission spectrum, together with atmospheric modelling, then gives clues to the properties of the exoplanet’s atmosphere. Chemical species composed of light elements—such as hydrogen, oxygen, carbon, sodium and potassium—have in this way been detected in the atmospheres of several hot giant exoplanets,,,, but molecules composed of heavier elements have thus far proved elusive. Nonetheless, it has been predicted that metal oxides such as titanium oxide (TiO) and vanadium oxide occur in the observable regions of the very hottest exoplanetary atmospheres, causing thermal inversions on the dayside,. Here we report the detection of TiO in the atmosphere of the hot-Jupiter planet WASP-19b. Our combined spectrum, with its wide spectral coverage, reveals the presence of TiO (to a confidence level of 7.7σ), a strongly scattering haze (7.4σ) and sodium (3.4σ), and confirms the presence of water (7.9σ) in the atmosphere,.