Binary Stars

astronomy · gravity · stars · space

Two stars orbiting. Binary stars are pairs of stars held together by gravity, spinning around a point between them like a cosmic seesaw. They're some of the most important stars we study because watching them helps scientists measure how heavy stars actually are.

Invisible pairs revealed. Many binary stars look like a single dot of light to our eyes, but through a telescope they split into two separate stars. These are called visual binaries, and some take hundreds or even thousands of years to complete one full orbit around each other.

Stars that eclipse. When two stars orbit in just the right way, they pass in front of each other from our view on Earth, making their light flicker like a cosmic blink. These special pairs are called eclipsing binaries, and they help astronomers learn tons about how stars work.

Testing star science. Binary stars let scientists test their ideas about how stars are born, live, and eventually die. By watching how two stars interact with each other, researchers can understand the life story of stars better than studying single stars alone.