Showing posts with label galaxy. Show all posts
Showing posts with label galaxy. Show all posts

Wednesday, March 27

Galaxy Definition

Introduction to galaxy definition:

We always observes that there are infinite numbers of stars in the sky. The question arises hat how are the stars distributed in the space. Astronomers have found that the starts are arranged in the huge groups. These groups are called the galaxies. The stars in the galaxy are held together by the gravitational attraction between them. Here we discuss about the galaxy.

A few points about Galaxy

Generally, a galaxy is the clusters of stars in the large amount. A component of the universe that has a huge group of stars and other celestial bodies bound together by the force of gravitation is called a galaxy. Apart from stars, a galaxy also has huge clouds of gases from which the new stars are born. A galaxy may have planets, moons, asteroids, comets and another celestial bodies. The number of stars in a galaxy can range about a million to hundred of billions. It is also estimated that there are over 100 billions galaxies in the universe and astronomers are discovering more every day. The galaxy in which our sun is located is called the Milky Way galaxy or Akashganga.

Types of galaxies

Galaxies have different shapes. Based on the shapes, mainly, three types of the galaxies are there, which are  Spiral galaxies, elliptical galaxies and irregular galaxies. In a spiral galaxy the stars forms a big spiral pinwheel. The Milky Way galaxy is a spiral galaxy. In an elliptical galaxy the stars are confined mainly in ellipsoid volume. An irregular galaxy does not have any particular shape.

Conclusion to galaxy

Most of the stars of the Milky Way galaxy lie in the disc shaped region, this region is called the galactic disc. The central part of the disc is thicker and bulges on both the sides. The density of stars in the bulge is much higher than that in the outer region of the galaxy. Milky Way galaxy is a large galaxy. The diameter of the galactic disc is about 100, 000 light years and its average thickness is about 70 light years.