Bright star in the night sky. The most is a fixed star. The fixed star means the star that twinkles voluntarily like the sun. The fixed star on the outline in the appearance exists little shifting position on the celestial globe. The fixed star was examined from various angles.
The sun is a fixed star that exists in the shortest distance to the earth.
There are 6000℃ temperature, and the main atmosphere is made of hydrogen and helium. Please look at the page of the sun in detail.
Galaxyis a large population from such stellar and interstellar material.
The size is overcrowded within the range of the diameter several hundred thousand light-year wide in the most basic object of space following the fixed star.
※Light-year … Unit that shows distance to fixed star
……Light is a distance in one year advanced in the vacuum. Because the speed of light is about 300,000km/s, it becomes one light-year = about 9.4 trillion km.
It is one of the classifications of galaxy in the fixed star who is a large group. It is distinguished from whirlpool [jouginga] and the irregular galaxy. This elliptical galaxy is made from an old star in a young star and exist in no content of the gas and Chile.
It has the whirl structure, the fixed star and the interstellar matter gather in discoid, and the swirling galaxy is made. Concentration by gravity balances the centrifugal force by the rotation of the disk, and shape can be kept.
It is a gas that consists of the cosmic dust and the interstellar gas, etc. with the settlement in gravity it is tossed about space. It is distinguished now though it seems to have been thought that the Milky Way was one of the nebulas before.
（The right picture is Great Nebula of Orion.）
The rose nebula is a nebula where it is in 4600 light-years, and is born the fixed star. It is red and called the rose nebula as if the flower.