赤い矮星の星冠からの放射線の地上からの観測
1Universität Hamburg, Hamburger Sternwarte, Germany. jschmitt@hs.uni-hamburg.de
Nature
|August 3, 2001
まとめ
現在,地上望遠鏡で恒星のコロナを研究することができ,CN Leonisの鉄放射線を明らかにしています. これは,太陽に似た恒星の冠状熱メカニズムを理解するための新しい窓を開きます.
科学分野:
- 天文学と天体物理学について
- 恒星物理学 恒星物理学
- プラズマ物理学 プラズマ物理学
背景:
- 太陽のような星には,106 Kを超える磁気的に閉じ込められたプラズマのコロナがあります.
- 恒星の冠状の加熱メカニズムは,太陽でさえ,まだ十分に理解されていません.
- 以前は,恒星の冠は主に宇宙からのX線放射によって研究されていました.
研究 の 目的:
- 地上からの光学観測を用いて赤矮星のコロナからの放射を検出・分析する.
- 観測と太陽現象を比較することによって,恒星のコロナの加熱機構を調査する.
- 恒星のコロナ研究のための新しい,アクセシブルな方法を確立すること.
主な方法:
- 地上望遠鏡を使って赤矮星CN Leonisの観測.
- 高イオン化鉄 (Fe XIII 3,388.1 A) の放射を検出する.
- プラズマの性質を推論するために,スペクトル線幅の分析.
主要な成果:
- CN Leonisのコロナから鉄の排出線が検出されました.
- 推論されたX線流は,以前の宇宙ベースの測定と一致しています.
- 18.4 km s-1 の非熱線幅は,太陽と恒星の環境の冠状熱の類似性を示唆しています.
結論:
- 地上からの光学観測は,恒星のコロナへの新しい,高度にアクセス可能な窓を提供します.
- この発見は,太陽のような星々における類似の磁気冠状の加熱機構の仮説を裏付けている.
- 地上機器によるスペクトル解像度の向上は,宇宙からのX線観測に比べ,大きな利点をもたらします.
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