Embedded Files
A galaxy is a system made up of stars, stellar remnants, gas, dust, and dark matter, all held together by gravity. The term "galaxy" comes from the Greek word galaxias, meaning "milky," which refers to the Milky Way galaxy that includes our Solar System. Galaxies vary widely in size, from small dwarf galaxies containing fewer than a thousand stars to enormous supergiant galaxies that can have up to one hundred trillion stars. Each star orbits the galaxy's center of mass. The majority of a galaxy’s mass is in the form of dark matter, with only a small fraction visible as stars and nebulae. Most galaxies also have a supermassive black hole at their center.
The Milky Way Galaxy
The Milky Way is the galaxy that contains our Solar System, along with billions of other stars, planets, and celestial objects. It is a spiral galaxy, meaning it has a flat, rotating disk with several distinct arms that radiate out from a central bulge. The Milky Way spans about 100,000 light-years in diameter and contains an estimated 200-400 billion stars, including the Sun.
Google Sites
Report abuse