小型の二重小惑星の起源としての回転分解
Kevin J Walsh1, Derek C Richardson, Patrick Michel
1UMR 6202 Cassiopée, University of Nice-Sophia Antipolis, CNRS, Observatoire de la Côte d'Azur, BP 4229, 06304 Nice Cedex 4, France. kwalsh@oca.eu
Nature
|July 11, 2008
まとめ
熱的なYORP効果は,小惑星が衛星を形成する方法を説明することができます. このメカニズムは,ゴミの堆積小惑星の回転を引き起こし,近軌道二次体を形成する質量を流す.
科学分野:
- 惑星科学は惑星科学である.
- 天文学 天文学
- 天体物理学 天体物理学
背景:
- 衛星を持つ小惑星は,近地小惑星のペアからカイパーベルトのオブジェクトまで,太陽系全体で観測されています.
- 小惑星のバイナリ群は,地球近くや内部のメインベルトの集団に多く見られ,素早く回転するプライマリー群と,近い円形の二次軌道を特徴としています.
- 直径10km未満の小惑星の約15%が衛星を持っているが,これらのバイナリーの形成メカニズムは不明のままである.
研究 の 目的:
- 小惑星のバイナリの形成メカニズムを調査する.
- 異なるダイナミックな集団における小惑星バイナリの共通の特徴を説明するために.
主な方法:
- 熱的なYORP効果を用いた"ゴミの山"小惑星のスピンアップをモデル化.
- 批判的に回転する天体からの質量流出と衛星増積条件を分析する.
- 観測された小惑星系とモデルで生成されたバイナリ属性を比較する.
主要な成果:
- 熱的YORP効果は,近地とメインベルトの両方の集団で小惑星のバイナリを形成するための統一されたメカニズムを提供します.
- ゆっくりと回転する長方形の小惑星から流れる質量は,特定の条件下で衛星に蓄積されます.
- このモデルは,小惑星のバイナリ群の観測された性質を,その軌道特性と1999 KWの例 (4) を含め,成功裏に再現しています.
結論:
- 熱的YORP効果は,小惑星のバイナリ群の形成に起因する主なメカニズムである.
- このメカニズムは,小惑星の周りの衛星の普及と特性を説明します.
- この発見は,異なるダイナミックな環境における小惑星バイナリの観測を調和させるものである.
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