Define galaxy. In which galaxy our solar system falls?
1 Answer
Galaxy is a huge assembly of stars, dust and gases mutually held together by gravitational force. There are about 1011 galaxies and each galaxy contains about 1011 stars. Our solar system falls in milky way galaxy.
Galaxies differ from one another in shape, with variations resulting from the way in which the systems were formed and subsequently evolved. Galaxies are extremely varied not only in structure but also in the amount of activity observed. Some are the sites of vigorous star formation, with its attendant glowing gas and clouds of dust and molecular complexes. Nature has provided an immensely varied array of galaxies, ranging from faint, diffuse dwarf objects to brilliant spiral-shaped giants. Virtually all galaxies appear to have been formed soon after the universe began, and they pervade space, even into the depths of the farthest reaches penetrated by powerful modern telescopes. Galaxies usually exist in clusters, some of which in turn are grouped into larger clusters that measure hundreds of millions of light years across.
- A vast collection of billions of star, gases and dust particles in the universe is called galaxy.
- Galactic center a central point of the galaxy around which all stars and constellations move.
- The time taken by the sun to complete one revolution around the galactic center is called one cosmic year.
- The galaxy whose shape ranges from round to flattened disc is called elliptical galaxies.