基礎科学の立場から、自然環境と人間活動にかかわる教育・研究を行っています
神戸大学 発達科学部 人間環境学科 自然環境論コース TOP > 自然環境論セミナー
＜Last update : 2019.12.11＞
第258回 「自然環境論セミナー」
| 題目 | Protostellar and Protoplanetary Disks |
|---|---|
| 講演者 | James Noboru Imamura（オレゴン大学教授） |
| 日時 | 2019年12月12日（木）15:10-16:40 |
| 場所 | 神戸大学人間発達環境学研究科 G302教室（鶴甲第二キャンパス） 詳しくはこちら |
| 要旨 | A fundamental question in astronomy first posed in ancient times, is that of the origin of the Solar System. Today it is accepted that the collapse of dense cores in giant molecular clouds leads to the formation of stars (e.g., see Armitage 2011). In most proposed scenarios, the cores do not collapse directly to stars, they first pass through an intermediate phase where a nascent star forms surrounded by a circumstellar disk because of the large specific angular momentum of the cloud; the formation of stars and planetary systems results after mass and angular momentum are redistributed within these massive disks. This scenario had its origins in the 18th century when Swedenborg (1734), Kant (1755) and Laplace (1796) put forth, without observational support, the Nebular theory for the formation of the Solar System wherein planets formed in a massive disk orbiting about the young Sun (e.g., Woolfson 1993). Today, although aspects of the process remain elusive, the original vision has been firmly established. The mechanism, however, by which Jupiter-like planets are produced is not settled. Currently, it is thought that Jupiter-like planets form either through: (i) the core-accretion scenario where planet growth starts from the coalescence of dust particles in the disk and concludes with the gravitational capture of gas from the disk; and/or (ii) direct gravitational collapse driven by disk instabilities. No singular piece of evidence establishes which theory is the most plausible mechanism for the formation of Jovian planets. In my talk, I review observations of planets and planet forming regions, and the current state of modeling of planet formation mechanisms. 連絡先：伊藤真之（人間環境学専攻 環境基礎論講座） |
