On the order of 100,000 galaxies make up the Local Supercluster, and about 51 galaxies are in the Local Group (see list of nearest galaxies for a complete list). Everything in a galaxy moves around a centre of mass, which is also an effect of gravity. There are various types of galaxies: elliptical, spiral and lenticular galaxies, which can all be with or without bars. The Milky Way is an example of a spiral galaxy. In addition to shape, galaxies may be notable due to special properties, such as interacting with another galaxy, producing stars at an unusual rate, or having an active galactic nucleus. The shape of a galaxy tells scientists about how it was born, how and when it has formed stars, and how it has interacted with its neighbors. Examine never-before-seen galaxy images made by the James Webb Space Telescope and describe their attributes to help scientists study galaxy evolution. Galaxy, any of the systems of stars and interstellar matter that make up the universe. Many such assemblages are so enormous that they contain hundreds of billions of stars. If you are new to Galaxy start here or consult our help resources. You can install your own Galaxy by following the tutorial and choose from thousands of tools from the Tool Shed. Galaxies consist of stars, planets, and vast clouds of gas and dust, all bound together by gravity. The largest contain trillions of stars and can be more than a million light-years across. The smallest can contain a few thousand stars and span just a few hundred light-years. What Is a Galaxy? The Short Answer: A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems, all held together by gravity. We live on a planet called Earth that is part of our solar system. But where is our solar system? It’s a small part of the Milky Way Galaxy. Discover the latest in electronic & smart appliance technology with Samsung. Find the next big thing from smartphones & tablets to laptops & tvs & more. Shop Samsung Galaxy smartphones, from the latest foldable phones to everyday devices with Galaxy AI and innovative features. Find yours at Samsung US.