炭素大気を有する白矮星
P Dufour1, J Liebert, G Fontaine
1Department of Astronomy and Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, Arizona 85721, USA. dufourpa@as.arizona.edu
Nature
|November 23, 2007
まとめ
天文学者は,炭素豊富な大気を持つ新しい白矮星を発見し,既存の恒星の進化モデルに挑戦しました. これらの発見は,アシンプトティック・ジャイアント・ブランチ・フェーズ後の恒星の新たな進化経路の可能性を示唆している.
科学分野:
- 天文学 (astronomy) 天文学 (astronomy) とは,天文学 (astronomy) とは,天文学 (astronomy) とは,天文学 (astronomy) とは
- 恒星の進化について
- ホワイト・ダワーフの研究
背景:
- 白い矮星は,太陽の8〜10倍の質量を持つ恒星の恒星進化の終点である.
- ほとんどの白矮星は,ヘリウムおよび/または水素の外層を持つ炭素-酸素の核を持っています.
- 伝統的に,白矮星は,大気成分によって分類される:水素に富んだ (DA) またはヘリウムに富んだ (非DA).
研究 の 目的:
- 異常な大気組成を持つ白矮星を発見したことを報告するために.
- これらの新しい恒星物体の進化的意味を調査するために.
- これらの発見が現在の恒星の進化論に合っているかどうかを判断する.
主な方法:
- 白い矮星を特定し分析するための観測天文学.
- 大気組成を決定するスペクトル分析.
- 観測された大気のパラメータと,恒星の進化の理論モデルを比較する.
主要な成果:
- 大気は主に炭素で構成されているいくつかの白矮星を発見した.
- これらの炭素に富んだ白矮星は,水素やヘリウムの痕跡がほとんどない.
- 観測された大気のパラメータは,アシンプトシズム後の巨大な枝の進化に関する既存の理論と一致しません.
結論:
- 新しく発見された炭素大気を持つ白矮星は,新しい恒星の進化のシーケンスを表しているかもしれない.
- これらの天体は,PG 1159の恒星H1504+65.5のより冷たい対称である可能性があります.
- これらのユニークな白矮星の進化を完全に理解するには,さらなる研究が必要です.
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