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arXiv 2401.01465astro-ph.EP
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超热木星WASP-121b的大气是否存在变化?

Is the atmosphere of the ultra-hot Jupiter WASP-121b variable?

Quentin Changeat, Jack W. Skinner, James Y-K. Cho, Joonas Nättilä, Ingo P. Waldmann, Ahmed F. Al-Refaie, Achrène Dyrek, Billy Edwards, Thomas Mikal-Evans, Max J… 展开作者

Quentin Changeat, Jack W. Skinner, James Y-K. Cho, Joonas Nättilä, Ingo P. Waldmann, Ahmed F. Al-Refaie, Achrène Dyrek, Billy Edwards, Thomas Mikal-Evans, Max Joshua, Giuseppe Morello, Nour Skaf, Angelos Tsiaras, Olivia Venot, Kai Hou Yip

AI总结:

针对超热木星WASP-121b的大气是否存在变化这一问题,研究通过统一处理哈勃观测数据并结合大气反演与动力学模拟,证实其存在准周期性天气模式,时变信号源于风暴和锋面活动。

摘要:

我们对哈勃太空望远镜观测到的超热木星WASP-121b大气进行了综合分析。通过统一方法处理凌日、食和相位曲线观测数据,并解决仪器系统偏差后,我们使用复杂的大气反演方法提取了大气热结构、化学组成和云特性的可靠约束。分析表明,观测结果与日间从约0.1巴开始的强热逆温、太阳到亚太阳金属丰度Z(即-0.77 < log(Z) < 0.05)以及超太阳碳氧比(即0.59 < C/O < 0.87)一致。更重要的是,利用该行星高信噪比的重复观测数据,我们识别出以下明确的时变信号:i)两条相位曲线之间假定热点偏移的变化;ii)凌日和食过程中光谱特征的变化。通过高分辨率模拟WASP-121b大气的全球动力学,我们发现识别出的信号与准周期性天气模式(即大气变化)一致,其特征在观测探测水平(约5%至约10%)上以约5个行星日的时间尺度变化;在模拟中,天气模式源于风暴和锋面的形成与移动,导致大气的热(和冷)斑块随时间变形、分离和混合。

英文摘要:

We present a comprehensive analysis of the Hubble Space Telescope observations of the atmosphere of WASP-121 b, a ultra-hot Jupiter. After reducing the transit, eclipse, and phase-curve observations with a uniform methodology and addressing the biases from instrument systematics, sophisticated atmospheric retrievals are used to extract robust constraints on the thermal structure, chemistry, and cloud properties of the atmosphere. Our analysis shows that the observations are consistent with a strong thermal inversion beginning at ~0.1 bar on the dayside, solar to subsolar metallicity Z (i.e., -0.77 < log(Z) < 0.05), and super-solar C/O ratio (i.e., 0.59 < C/O < 0.87). More importantly, utilizing the high signal-to-noise ratio and repeated observations of the planet, we identify the following unambiguous time-varying signals in the data: i) a shift of the putative hotspot offset between the two phase-curves and ii) varying spectral signatures in the transits and eclipses. By simulating the global dynamics of WASP-121 b atmosphere at high-resolution, we show that the identified signals are consistent with quasi-periodic weather patterns, hence atmospheric variability, with signatures at the level probed by the observations (~5% to ~10%) that change on a timescale of ~5 planet days; in the simulations, the weather patterns arise from the formation and movement of storms and fronts, causing hot (as well as cold) patches of atmosphere to deform, separate, and mix in time.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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