250K~430Kの温度を持つ,通過する巨大惑星です
H J Deeg1, C Moutou, A Erikson
1Instituto de Astrofísica de Canarias, C. Via Lactea S/N, E-38205 La Laguna, Tenerife, Spain. hdeeg@iac.es
Nature
|March 19, 2010
まとめ
研究者らは,大きな軌道を持つ温帯系外惑星CoRoT-9bを発見した. その特徴は,標準的な惑星進化モデルと一致し,ガス巨人の組成に関する新しい洞察を提供します.
科学分野:
- 天文学と天体物理学について
- エクソプラネット科学 エクソプラネット科学
背景:
- 400以上の系外惑星が発見されており,約70個が通過行動を示しています.
- トランジットの系外惑星は,詳細なパラメータの導出と大気の研究を可能にします.
- 以前の発見は,CoRoT-7b.のような地上の惑星を含む,短期間惑星に焦点を当てていた.
研究 の 目的:
- CoRoT-9b.b系外惑星の通過観測を報告する.
- CoRoT-9bの軌道パラメータと温度を特徴付けるために.
- CoRoT-9bの性質を,既存の惑星進化モデルと比較するために.
主な方法:
- CoRoT-9bの通過観測が行われました.
- 軌道周期,離心率,および周辺星からの距離を決定した.
- 光球の温度は,軌道と恒星の性質に基づいて推定されました.
主要な成果:
- CoRoT-9bは,周期が95.274日,離心率が低い (0.11 +/- 0.04) 太陽のような恒星を周回しています.
- この惑星は,既知の通過惑星の中で,最も大きな周辺星距離 (0.36AU) を保持しています.
- 惑星の推定光球温度は250〜430Kの範囲で,温帯気候を示しています.
- CoRoT-9bの大きさは,周期が短い惑星とは異なり,潮による加熱に大きく影響されない.
結論:
- CoRoT-9bの性質は,標準的な惑星進化モデルと一致しています.
- その内部の構成は木星と土星の内部の構成と似ています.
- この発見は,広い軌道を持つ温帯系外惑星を理解するためのユニークなケーススタディを提供します.
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