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超海王星の天体UB313は冥王星より大きい
F Bertoldi1, W Altenhoff, A Weiss
1Argelander Institute for Astronomy, University of Bonn, Auf dem Hügel 71, D-53121 Bonn, Germany. bertoldi@astro.uni-bonn.de
Nature
|February 3, 2006
まとめ
遥かなる物体2003 UB313は,冥王星を上回る最大の既知の超海王星物体である. その高い反射性は,冥王星に似た,メタン豊富な氷の表面を示唆しています.
科学分野:
- 天文学と天体物理学について
- 惑星科学は惑星科学である.
- 太陽系ダイナミクス 太陽系ダイナミクス
背景:
- 2003年 遠い太陽系天体UB313がアフェリオン近くで発見された.
- その軌道の特徴 (高離心率,傾き) は,それを"散らばった円盤"物体として分類する.
- 散らばった円盤の物体は,おそらく,海王星の向こうにある氷の体の領域であるカイパーベルトから発生しています.
研究 の 目的:
- 2003 UB313.の実際のサイズと表面特性を決定するために.
- 2003 UB313を冥王星や他の超海王星の天体と比較する.
- 遠い太陽系天体の組成と反射力を理解する.
主な方法:
- 1.2mmの波長での熱放射の観測.
- 光学的な明るさ測定と組み合わせた熱放出データ.
- 観測データに基づいて直径とアルベドを計算し,測定の不確実性とオブジェクトの方向性を考慮します.
主要な成果:
- 2003 UB313の直径は3,000 +/- 300 +/- 100kmで,冥王星 (2300km) よりも大きい.
- オブジェクトのアルベドは0.60 +/- 0.10 +/- 0.05で,非常に反射する表面を示しています.
- アルベドは冥王星に似ており,メタンが誘発した氷の表面構成を示唆しています.
結論:
- 2003 UB313は,既知の最大の超海王星天体である.
- その表面の組成は,おそらく氷と非常に反射的なもので,冥王星に似ています.
- この発見は,太陽系外部のオブジェクトの多様性と性質の理解に貢献します.
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