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土星の最大のリングである
Anne J Verbiscer1, Michael F Skrutskie, Douglas P Hamilton
1Department of Astronomy, University of Virginia, Charlottesville, Virginia 22904-4325, USA. verbiscer@virginia.edu
Nature
|October 9, 2009
まとめ
土星には,これまでに発見されていない巨大なリングシステムが存在し,既知のリングをはるかに超えて,その衛星のフィービーと結びついています. この巨大な塵の輪は,フィービーへの衝突によって維持され,惑星から前例のない距離に達します.
科学分野:
- 惑星科学は惑星科学である.
- 天体物理学 天体物理学
- 太陽系ダイナミクス 太陽系ダイナミクス
背景:
- 惑星環は,通常,衛星形成を阻害する重力により,宿主惑星の近くに閉じ込められています.
- 木星のゴッサマーリングや土星のEリングのような例外は,惑星半径5〜10まで広がる広い塵のシートです.
- これらの既知の拡張リングは,源衛星からの塵によって継続的に供給されています.
研究 の 目的:
- 土星の周りの広大な,これまで未知のリングシステムの発見と特徴を報告するために.
- 月のフィーベに関連したこの広大なリング構造の起源とダイナミクスを調査する.
主な方法:
- 観測データを分析して,新しいリングシステムの範囲を特定し,定義する.
- 粒子の分布,軌道動力学,環の維持機構を理解するためのダイナミック・モデリング.
主要な成果:
- 土星の周りの巨大なリングを発見し,土星の半径128から207まで広がった.
- リングの垂直厚さ (40R(S)) は,フィーベの軌道垂直運動と相関しています.
- リングの光学的な深さは低く,木星の最も薄いゴッサマーリングに匹敵するが,粒子の密度は低い.
- リング粒子は,おそらくフィービーへの衝撃から発生し,内側に移動し,一部はイアペタスに到達します.
結論:
- 土星は,外側の衛星のフィービーと関連付けられている例外的に大きなリングシステムを所有しています.
- フィービーへの衝撃は,この広大なリングの材料の潜在的な源である.
- リング粒子は,惑星間距離にまで及ぶ土星のシステムの動力学に役割を果たしています.
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