熱い木星の大気中の太陽C/Oと太陽下金属性
Michael R Line1,2, Matteo Brogi3,4,5, Jacob L Bean6
1School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA. mrline@asu.edu.
Nature
|October 28, 2021
まとめ
この研究では,熱い木星のWASP-77Abで大気中の炭素と酸素を測定し,太陽に近い炭素と酸素の比率を明らかにしました. これらの発見は,惑星の形成と移住の歴史を決定するのに役立ちます.
科学分野:
- 外惑星科学
- 大気化学
- 天体化学
背景:
- 熱い木星の大気組成は その形成と移動のヒントを与えてくれます
- 以前の研究では,熱い木星の大気中の炭素 (C) と酸素 (O) の同時測定が欠けていました.
- この制限は,炭素と酸素の比率 (C/O) と全体的な金属性の正確な決定を妨げました.
研究 の 目的:
- 熱い木星WASP-77AbのC/O比率と金属性を決定する.
- 惑星の形成位置と 移動経路を推測するために
主な方法:
- 熱い木星WASP-77Abを観測した.
- 大気中の水 (H2O) と一酸化炭素 (CO) の量混合比の制限値
- C/HとO/Hの太陽値に対する大気濃度.
主要な成果:
- H2Oの濃度が9.5×10−51.5×10−4とCOの濃度が1.2×10−42.6×10−4に制限されている.
- 計算された大気C/O比率は0.59 ±0.08,太陽値 (0.55) に近い.
- 亜太陽 (C+O) /Hの豊富さが見つかりました 金属が少ない大気を示唆しています
結論:
- WASP-77Abの太陽に近いC/O比は,円盤のない移動とC豊富な大気を含むシナリオと矛盾しています.
- この結果は惑星が原惑星円盤を移動するモデルを 支持している.
- この研究は,外惑星の大気中のC/Oを正確に測定する能力を示しています.
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