Tidal Processes in Planetary and Stellar Systems

行星和恒星系统中的潮汐过程

• 批准号: RGPIN-2018-05886
• 负责人: Wu, Yanqin
• 金额: $ 2.99万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=668996
• 关键词: Tidal; Processes; Planetary; Stellar; Systems

Tides are experienced daily here on Earth, they also occur widely in the celestial realm. Here, I propose to study two of their manifestations.******Hot Jupiters. the first-known population of extra-solar planets, orbit their stars at implausibly close ranges. They are often suggested to be the products of dynamical migration: formed much further away than their current locations, angular momentum exchange with their neighbours (either stellar or planetary ones) may gradually squeeze their original round orbits into very narrow ellipses; strong tides are raised on these planets as they sway by their stars periodically. If the tidal sloshing can be dissipated into heat, the planet orbit will decay and a hot Jupiter is born. Such a theory of dynamical migration, while neatly explaining many of the observed features of hot Jupiters, contains a number of major weaknesses -- all related to our lack of understandings on the tidal process. So in order to firmly establish the origin of hot Jupiters, I propose to study the tidal process in detail. At the end of such a study, we should be able to explain the current orbits and sizes of these planets. It will be satisfying to finally understand this class of exotic objects that nature produces.******Another very extreme tidal process occurs when a small planet passes very close from the surface of a massive body (a planet or a star). The former body can be shredded into millions of little debris, with some of them escaping the gravitational pull of the destroyer and eventually re-conglomerating into larger clumps. Such a catastrophic event, we propose, may be responsible for producing the many bright dusty disks we see around stars, the so-called debris disks. This breaks away from the conventional picture of debris disk formation, where it is hypothesized that quantities of planetesimals, unable to be incorporated into planets at early days, remain behind and gradually grind down to dust over billions of years. I propose to study the details of the tidal disruption event, in order to predict the frequency and the appearance of debris disks this can give rise to. Such a work also have applications for the Kuiper belt objects in our own solar system.

潮汐每天在地球上每天都有潮流，它们也在天体领域中广泛发生。在这里，我建议研究它们的两种表现。******热木星。超极行星的第一个已知种群在令人难以置信的接近范围内绕恒星绕。通常建议它们是动态迁移的产物：与目前的位置相比，与邻居（恒星或行星的角度）交流更远的地方，可能会逐渐将其原始的圆形轨道挤入非常狭窄的椭圆机；当它们周期性地摇摆着恒星时，这些行星在这些行星上浮出水面。如果将潮汐晃动散发到热量中，则行星轨道将腐烂，并诞生热木星。这种动态迁移的理论，同时用整齐地解释了热木星的许多特征，其中包含许多主要弱点 - 这与我们对潮汐过程的理解不足有关。因此，为了牢固地建立热木星的起源，我建议详细研究潮汐过程。在这项研究的结尾，我们应该能够解释这些行星的当前轨道和大小。最终了解自然产生的这类外来物体将是令人满意的。前身体可以被切成数百万个小碎片，其中一些逃避了驱逐舰的引力，并最终重新质量重新构成更大的团块。我们提出，这样的灾难性事件可能是为了产生我们在恒星，即所谓的碎屑磁盘周围看到的许多明亮的尘土飞扬的磁盘。 这从碎片盘形成的传统图片中脱颖而出，在这种情况下，假设在早期无法将行星纳入行星中，落后于行星，并逐渐磨碎到数十亿年的灰尘。我建议研究潮汐破坏事件的细节，以预测可能引起的碎屑磁盘的频率和外观。 这样的工作还为我们自己的太阳系中的Kuiper带对象提供了应用。