| 报告摘要： |
In 2020, we reported the discovery of a young (only 30-40 Myr) snake-like structure (dubbed a stellar “snake”) in the solar neighborhood from Gaia DR2. The average distance of this structure is about 310 pc from us. Both the length and width are over 200pc, but the thickness is only about 80pc. The “snake” has one tail and two dissolving cores, which can be clearly distinguished in the 6D phase space. The whole structure includes thousands of members with a total mass of larger than 2000 M⊙ in a uniform population. The population is so young that it cannot be well explained with the classical theory of tidal tails. We therefore suspect that the “snake” is hierarchically primordial, rather than the result of dynamically tidal stripping, even if the “snake” is probably expanding. This finding will provide us an ideal test-bench to study the history of the stellar formation and environmental evolution.
Recently, we extend the structure of the “snake” by a factor of more than 2, and make the number of its member candidates beyond ten thousand, interestingly, most of which are the pre-main sequence stars. In this talk, I will present the panoramic structure and properties of the stellar “snake”. |
