GALAXY
- November 1, 2020
- Posted by: OptimizeIAS Team
- Category: DPN Topics
No Comments
Subject: Science & tech
Context: Spiral galaxy bars may prevent new stars.
Concept:
- A galaxy is a sprawling space system which is composed of stars, dust, interstellar gas, stellar remnants, and dark matter and all held together by gravity.
- The universe has many galaxies, and each carries millions of stars which are bounded by a unique force known as gravitational force. The solar system where our earth exists is in the Milky Way Galaxy.
- Galaxies differ from each other in shape, size, colour and composition. There are three types of galaxies that we find in the universe.
Types of Galaxies:
Elliptical Galaxies
- These type of galaxies are like flattened balls of old stars and contain very little gas. It also includes the most massive galaxies containing a trillion stars.
Spiral Galaxies
- Spiral galaxies have a flattened the shape. They have a bulge in the centre composed of old stars surrounded by a disk of young stars and are arranged in spiral arms.
Irregular Galaxies
- As its name suggests, Irregular Galaxies have no particular shape. There are billions of galaxies in the universe, the centre of the galaxy releases a huge amount of heat, radiation, radio waves and x-rays.