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熱い木星の惑星WASP-18bbの軌道周期は0.94日です
Coel Hellier1, D R Anderson, A Collier Cameron
1Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK. ch@astro.keele.ac.uk
Nature
|August 29, 2009
まとめ
我々はWASP-18bを発見し,極端な潮相互作用を持つ熱い木星である. その急速な内向きの渦巻きは,珍しい恒星状態か,または以前に想定されたよりもはるかに弱い熱い木星における潮の消去を示唆しています.
科学分野:
- 外惑星科学とは,外惑星科学のこと.
- 天体物理学 天体物理学
- 惑星のダイナミクス
背景:
- ホットジュピターは,宿主星に近い軌道に回っているガス巨星です.
- 内部への移動は,円盤の相互作用や惑星対惑星の散乱に起因する.
- 近くにある熱い木星は,強い潮力を経験し,潮の消去に関する洞察を提供します.
研究 の 目的:
- 新しいホットジュピター,WASP-18b.の発見を報告するためです.
- その極度の軌道パラメータが,潮分散理論に及ぼす影響を調査する.
- 恒星系における潮分散パラメータ (Q) をテストするために.
主な方法:
- 観測天文学によるWASP-18bの発見.
- 軌道周期と質量の分析 (木星の10質量).
- 潮の相互作用と内向きのスパイラル時間スケールのモデリング.
主要な成果:
- WASP-18bの軌道周期は0.94日である.
- これは,以前研究されたシステムよりも,数倍も強い潮相互作用を示しています.
- 標準的な仮定 (Q ~ 10 ^ 6) の下では,WASP-18bは,恒星の寿命の1000分の1未満で内側へ渦巻く.
結論:
- WASP-18bの急速な内向きのスパイラルは,現在の潮消散モデルに挑戦しています.
- システムは,希少で短命な進化段階を表しているかもしれません.
- また,熱い木星における潮の消散は,太陽系の天体よりも著しく弱くなる可能性があります.
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