According to an astronomical paper published in the British journal Nature on the 19th, by tracking the movement of more than 6 million stars in the Milky Way, the Gaia Telescope found that the stellar group travels around the center of the Milky Way according to different routes. This non-uniform rotation pattern It is believed that the 'small collision' that occurred when hundreds of millions of years ago a smaller satellite galaxies passed nearby stirred the Milky Way.
Most of the stars in the Milky Way are located in their disk area (silver plate), a flat area around the central bulge of the Milky Way. The internal structure of the silver plate is affected by various factors. For example, the central rod-like structure of the Milky Way and the spiral arm cause the path. Offset, the influence of satellite galaxies can change the motion of stars. However, when modeling galaxies, it is generally believed that the motion of stars in a silver disk is basically in dynamic equilibrium, and the plane of the Milky Way is symmetrical.
This time, the University of Barcelona research team used the data of the Asia-Pacific Space Telescope to analyze the motion and position of the stars in the silver plate, and generated a special position-speed map, allowing astronomers to classify the star motion, from the data. Various spiral patterns were found. This does not mean that the stars move along the spiral, but rather that there are stellar groups that cross the Milky Way along different paths while still participating in the overall rotation.
The research team believes that this movement was caused by the Sagittarius dwarf galaxies passing through from 300 million to 900 million years ago. The past related studies have limited precision and include fewer stars, so they do not resolve the above differences. Sports mode.
Launched in 2013, the Gaia Telescope accurately observes stars in the center of the Milky Way, its two optical telescopes and three sciences. instrument It can measure the brightness, temperature and composition of stars.
