NASAのジェイムズ・ウェッブ宇宙望遠鏡を使用した天文学者らが、摂氏約80度という温暖な環境にある、希少な土星サイズの惑星「TOI-199b」の大気を調査した。今回の発見は、温暖な巨大系外惑星の詳細な観測として初の事例となる。
この惑星は地球から330光年以上離れた恒星の周りを公転しており、約100日で1周する。研究チームは、合計20時間の観測のうち7時間のトランジット（恒星面通過）中に透過分光法を用い、その大気中にメタンが存在することを検出した。
Astronomers using the James Webb Space Telescope have detected an unusually metal-poor atmosphere on the Jupiter-sized exoplanet TOI-5205 b, which orbits a small, cool star. The planet's atmospheric metallicity is lower than that of its host star, challenging theories of giant planet formation. The findings come from a study led by researchers at NASA's Goddard Space Flight Center and Carnegie Science.
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Astronomers used the James Webb Space Telescope to study the atmosphere of WASP-94A b, a tidally locked gas giant 690 light-years away. The observations revealed cloudy mornings and clear evenings on the planet. The findings were published in Science.
Astronomers at the University of Warwick have used a new AI system called RAVEN to confirm more than 100 exoplanets from NASA's Transiting Exoplanet Survey Satellite (TESS) data. The discoveries include 31 newly identified worlds, many orbiting close to their stars, along with thousands of candidates. The findings reveal rare planet types and precise measurements of planetary occurrence rates around Sun-like stars.
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New research indicates that hidden oceans on icy moons around outer planets may boil due to tidal heating, explaining unusual surface features. The study, published in Nature Astronomy, focuses on smaller moons like Enceladus, Mimas, and Miranda. Lead author Max Rudolph from UC Davis highlights the processes shaping these worlds over millions of years.
About 65 percent of Saturn's moon Titan consists of uniform flat plains likely coated in up to a meter of fluffy organic material from its atmosphere. Researchers analyzing radar data from NASA's Cassini spacecraft propose a two-layer surface model. This finding could inform future missions to the hazy moon.