银河系[Milky Way Galaxy] - 达人(其实～我是卧底，来自外星)

2005/04/21 | 银河系[Milky Way Galaxy]
类别(¤〖天文〗) | 评论(2) | 阅读(177) | 发表于 15:15: The spiral galaxy which the Sun and our solar system inhabit. The center of the Milky Way is located in the direction of the constellation Sagittarius, and the Sun is moving in its orbit towards the constellation Cygnus. The distance from the Earth to the center of the galaxy is 30,000 ly, and the orbital period of the Sun about the galactic center is 250 million years. There are approximately stars in the Galaxy. The Galaxy's dimensions are 100,000 ly in diameter and ly thick. According to three recent independent studies, the Sun lies ly north of the galactic plane, towards the constellation Coma Berenices (Sky & Telescope 1996).; 0