What are binary stars?

Binary stars are defined as pairs of stars that share a common gravitational center, meaning they are bound together by gravity and move in relation to one another. This relationship can lead to interesting dynamics, such as the exchange of material between the two stars or the observation of eclipsing binaries, where one star passes in front of the other from our viewpoint, causing variations in brightness.

Understanding binary stars is essential in the study of stellar formation and evolution, as these systems can provide critical information regarding the masses and compositions of stars. Additionally, binary systems can help astronomers measure distances within our galaxy, as well as refine our understanding of stellar lifecycles, aggregation, and the effects of gravitational interactions over time.

Other choices do not accurately define binary stars. While varying brightness could refer to variable stars, it does not specifically relate to binary systems. Stars that orbit around a gas cloud pertain more to aspects of star formation rather than binary relationships. Finally, being located in the same constellation refers to a visual grouping in the night sky rather than any physical connection between the stars involved.