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Scattering And Absorption of Light in Planetary Regoliths
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0.8gcm(-3) の低い密度は,トロイの木馬のバイナリ小惑星617パトロクルスにある
Franck Marchis1, Daniel Hestroffer, Pascal Descamps
1Department of Astronomy, University of California, 601 Campbell Hall, Berkeley, California 94720, USA. fmarchis@berkeley.edu
Nature
|February 3, 2006
まとめ
バイナリー系である木星のトロイの木馬小惑星617 Patroclusは,その構成要素が円状の軌道で動いていることを明らかにする特定の軌道を持っています. この発見は,小惑星が多孔性または氷状であることを示唆しており,太陽系の外側で形成された可能性が高い.
科学分野:
- 天文学と天体物理学について
- 太陽系探査 太陽系探査
- 小惑星の研究.
背景:
- 木星のトロイの木馬は,安定したラグランジュ点 (L4およびL5) で木星の軌道を共有する小惑星です.
- 小惑星617パトロクルスは,これまでに特徴づけられなかった軌道動態を持つ,唯一の既知のバイナリトロイの木馬小惑星です.
研究 の 目的:
- バイナリ小惑星617パトロクルスの軌道特性を決定する.
- 617 パトロクルスの構成要素の物理的性質と起源を,その軌道と熱のデータに基づいて推論する.
主な方法:
- 観測天文学は,バイナリコンポーネントの動きを追跡する.
- 小惑星の構成要素の大きさを推定するための熱測定.
- システムの動態をモデル化するための軌道力学計算.
主要な成果:
- 617 パトロクルスの2つの構成要素は,およそ円形な軌道で,共通の質量の中心を680kmで回転し,分離しています.
- コンポーネントの密度は0.8gcm−3という非常に低い密度で得られた.
- 密度が低いことは,有意な多孔性または水氷に富んだ組成を示唆する.
結論:
- 617パトロクルスの軌道と物理的性質は,太陽系の外側で形成された可能性があることを示しています.
- このバイナリートロイの木馬は,木星のトロイの木馬集団の小惑星の構成と形成の洞察を提供します.
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