Strong H2O and CO Emission Features in the Spectrum of KELT-20b Driven by Stellar UV Irradiation
Strong H2O and CO Emission Features in the Spectrum of KELT-20b Driven by Stellar UV Irradiation
复制标题
恒星紫外辐射驱动的 KELT-20b 光谱中强烈的 H2O 和 CO 发射特征
DOI：
10.3847/2041-8213/ac4968
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
J. Bean
中科院分区：
文献类型：
--
作者：
Guangwei Fu;D. Sing;J. Lothringer;D. Deming;Jegug Ih;E. Kempton;M. Malik;T. Komacek;M. Mansfield;J. Bean
了解你的星星，了解你的行星大气。每一颗有大气测量的系外行星都绕着一颗星星运行，恒星环境直接影响行星大气。在这里，我们展示了超热木星KELT-20 b的发射光谱，它提供了宿主恒星特性和行星大气热结构之间的观测联系。它是目前唯一一颗热辐射测量值在T eq = 2200 K范围内的行星，围绕早期A型星星运行。通过将它与FGK恒星周围的其他类似的超热彗星进行比较，我们可以更好地了解不同的宿主恒星类型如何影响行星大气。发射光谱覆盖0.6-4.5 μm，数据来自TESS、HST WFC 3/G141和Spitzer 4.5 μm通道。KELT-20 B具有SH 2 O = −0.097 ± 0.02的1.4 μm水特征强度度量，并且在WFC 3/G141（T B = 2402 ± 14 K）和Spitzer 4.5 μm通道（T B = 2930 ± 59 K）之间具有528 K的黑体亮度温度差。这些非常大的H2O和CO排放特征与A型宿主星星相结合，使KELT-20 b在其他类似的热彗星中成为一颗独特的行星。根据PHOENIX模型的计算，来自其宿主星星（Teff = 8720 ± 250 K）的丰富的FUV、NUV和光辐射是驱动其强烈的热反转和突出的发射特征的关键。
Know thy star, know thy planetary atmosphere. Every exoplanet with atmospheric measurements orbits around a star, and the stellar environment directly affects the planetary atmosphere. Here we present the emission spectrum of ultra-hot Jupiter KELT-20b which provides an observational link between host-star properties and planet atmospheric thermal structure. It is currently the only planet with thermal emission measurements in the T eq ∼ 2200 K range that orbits around an early A-type star. By comparing it with other similar ultra-hot Jupiters around FGK stars, we can better understand how different host-star types influence planetary atmospheres. The emission spectrum covers 0.6–4.5 μm with data from TESS, HST WFC3/G141, and Spitzer 4.5 μm channel. KELT-20b has a 1.4 μm water feature strength metric of SH2O = −0.097 ± 0.02 and a blackbody brightness temperature difference of 528 K between WFC3/G141 (T b = 2402 ± 14 K) and Spitzer 4.5 μm channel (T b = 2930 ± 59 K). These very large H2O and CO emission features combined with the A-type host star make KELT-20b a unique planet among other similar hot Jupiters. The abundant FUV, NUV, and optical radiation from its host star (Teff = 8720 ± 250 K) is expected to be the key that drives its strong thermal inversion and prominent emission features based on previous PHOENIX model calculations.
热木星全球环流模型中使用的辐射方案的精度测试
影响因子：
6.5
作者：
Amundsen D
通讯作者：
Amundsen D