ハッブル宇宙望遠鏡で紫外線で観測された木星の驚くべきオーロライベント

J C Gérard, D Grodent, V Dols

Science (New York, N.Y.)

|December 9, 1994

まとめ

紫外線画像を用いて観測された木星の強烈なオーロラ弧は,地球のオーロラに似た惑星の電流システムとのつながりを示唆する急速な変化を示しています. この激しい電子の降雨は木星の大気を著しく加熱する.

科学分野:

惑星科学は惑星科学である.
宇宙物理学宇宙物理学
大気科学大気科学

背景:

木星のオーロラは,エネルギッシュな粒子の降水によって引き起こされるダイナミックな現象です.
木星のオーロラからの放射を理解することは,磁気圏の過程を理解する上で鍵となるものです.

研究の目的:

ハッブル宇宙望遠鏡によって撮影された木星の北極光の紫外線画像を分析するために.
分離的なオーロラ弧の特徴と時間的変動を調査する.

主な方法:

ハッブル宇宙望遠鏡のフェイントオブジェクトカメラを使用して,紫外線画像の2セットを取得しました.
オーロラ・アークの明るさと放射率の分析.

主要な成果:

木星とほぼ相交する強烈な分離したオーロラ・アークが観測されました.
最大の電子降水量は約1W/m2に達し,太陽熱を大幅に上回りました.
弧の輝度は,20時間以内に1度以上の大きさで減少した.

結論:

木星のオーロラの明るさの急速な変化は,木星の現在のシステムにおける大規模な変動とのつながりを示唆しています.
この振る舞いは,地球上で観測される離散的なオーロラに類似しています.
オーロラの粒子の降水は,木星の上層大気を加熱し,熱圏風を駆動する上で重要な役割を果たしています.

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