宇宙级“乾坤大挪移”如何上演？天文学家揭秘热木星“奔赴”恒星之谜

Core Insights - The discovery of hot Jupiters, such as 51 Pegasi b, challenges traditional theories of planet formation and evolution, leading to a reevaluation of planetary systems [3][5][6] - Recent research indicates that approximately 60% of hot Jupiters migrate to their host stars within tens of millions of years, while about 40% appear over a timescale of millions to billions of years [7][8] Group 1: Hot Jupiter Characteristics - Hot Jupiters are gas giants similar in size to Jupiter but orbit very close to their host stars, resulting in extremely high surface temperatures [3][4] - The formation of hot Jupiters contradicts the classical "snow line" theory, which suggests that gas giants should form far from their stars [2][3] Group 2: Migration Theories - Three main hypotheses explain the migration of hot Jupiters: disk migration, scattering migration, and long-term chaotic evolution [5][6] - Disk migration suggests that gas giants lose energy and move closer to their stars within a few million years, while scattering migration occurs through interactions with other planets over about 100 million years [5][6] Group 3: Research Findings - The study analyzed 123 hot Jupiters and found a segmented decline in their occurrence rate as host star age increases, with a notable inflection point around 2 billion years [7][8] - The research team aims to create a comprehensive timeline of planetary system evolution and understand the underlying mechanisms driving the formation of various planetary populations [8][9]