Galaxies

Galaxies..

What is a Galaxy ? A galaxy is a massive, gravitationally bound system consisting of stars, an interstellar medium of gas and dust, and dark matter. Group means it can be around 100 billion stars. Our Galaxy is Milkyway, it is spiral galaxy in the form of disk in a spiral form. Milkyway contains around 200 billion stars. A light year is the distance that light travels in a year -- about 5.88 trillion miles (9.46 trillion kilometers). Means if one star is one light year away means. we are seeing the star as live but actually we are seeing it after one year.
There are many distinct types of galaxies, including ellipticals, spirals, Disk shaped and irregulars. The Milky Way is the galaxy which is the home of our Solar System together with at least 200 billion other stars (more recent estimates have given numbers around 400 billion) and their planets, and thousands of clusters and nebulae Milky Way galaxy, a large is a disk-shaped barred spiral galaxyAs a galaxy, the Milky Way is actually a giant, as its mass is probably between 750 billion and one trillion solar masses, and its diameter is about 100,000 light years.

Intergalactic space, or the space between the galaxies of the universe, is filled with an unsubstantiated plasma matter. This plasma has an average density less than one atom per cubic meter. There are believed to be more than one hundred billion galaxies within the total expanse of the universe. Many Galaxies contains dwarf satellite galaxies which forms a small group.

Andromeda Galaxy located at a distance of 2 million light years away is the nearest major galaxy and is of comparable size to our own galaxy. The Magellanic Clouds are irregular dwarf galaxies that are even nearer. The Small and Large Magellanic Clouds are located 165,000 light years and 195,000 light years away respectively. However, Andromeda is the nearest major galaxy and is the most distant celestial object still visible to the naked eye.