Evidence of a Clear Atmosphere for WASP-62b: The Only Known Transiting Gas Giant in the JWST Continuous Viewing Zone
Evidence of a Clear Atmosphere for WASP-62b: The Only Known Transiting Gas Giant in the JWST Continuous Viewing Zone
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DOI：
10.3847/2041-8213/abd18e
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发表时间：
2020-11
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通讯作者：
M. Alam;M. López-Morales;R. MacDonald;N. Nikolov;J. Kirk;J. Goyal;D. Sing;H. Wakeford;A. Rathcke;D. Deming;J. Sanz-Forcada;N. Lewis;J. Barstow;T. Mikal-Evans;L. Buchhave
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作者：
M. Alam;M. López-Morales;R. MacDonald;N. Nikolov;J. Kirk;J. Goyal;D. Sing;H. Wakeford;A. Rathcke;D. Deming;J. Sanz-Forcada;N. Lewis;J. Barstow;T. Mikal-Evans;L. Buchhave
在透射光谱探测的压力下，具有无云、无雾大气的系外行星代表了详细的大气特征和精确的化学丰度限制的宝贵机会。我们提出了热木星WASP-62 b的第一个光学到红外（0.3−5 μm）透射光谱，由哈勃/STIS和斯皮策/IRAC测量。该光谱的特征是在0.59 μm处的Na i吸收为5.1σ，其中首次从空间观测到Na D线的压力展宽翼。在2.1σ置信度下，0.4 μm处的光谱特征初步归因于SiH。我们的检索分析是一致的无云大气没有显着的污染恒星的异质性。我们模拟詹姆斯·韦伯太空望远镜（JWST）的观测，仪器模式的组合，以评估WASP-62 b的大气特性的潜力。我们证明，JWST可以决定性地检测Na，H2O，FeH，NH3，CO，CO2，CH 4和SiH在其早期释放科学（ERS）计划的范围内。作为目前在JWST连续观测区中已知的唯一一颗凌日巨行星，WASP-62 b可以证明是詹姆斯·韦伯时代详细大气特征的基准巨系外行星。
Exoplanets with cloud-free, haze-free atmospheres at the pressures probed by transmission spectroscopy represent a valuable opportunity for detailed atmospheric characterization and precise chemical abundance constraints. We present the first optical to infrared (0.3−5 μm) transmission spectrum of the hot Jupiter WASP-62b, measured with Hubble/STIS and Spitzer/IRAC. The spectrum is characterized by a 5.1σ detection of Na i absorption at 0.59 μm, in which the pressure-broadened wings of the Na D-lines are observed from space for the first time. A spectral feature at 0.4 μm is tentatively attributed to SiH at 2.1σ confidence. Our retrieval analyses are consistent with a cloud-free atmosphere without significant contamination from stellar heterogeneities. We simulate James Webb Space Telescope (JWST) observations, for a combination of instrument modes, to assess the atmospheric characterization potential of WASP-62b. We demonstrate that JWST can conclusively detect Na, H2O, FeH, NH3, CO, CO2, CH4, and SiH within the scope of its Early Release Science (ERS) program. As the only transiting giant planet currently known in the JWST Continuous Viewing Zone, WASP-62b could prove a benchmark giant exoplanet for detailed atmospheric characterization in the James Webb era.