Companion of Sirius

Astronomers discovered a companion star to Sirius, indicating that some stars have dark companions which are not luminous enough to be visible. This discovery suggested that stars can be influenced by gravitational pull from unseen objects, a concept which extended our understanding of stellar systems and their components.
 Friedrich Wilhelm Bessel Germany 1844 Companion of Sirius

Astronomers discovered a companion star to Sirius, indicating that some stars have dark companions which are not luminous enough to be visible. This discovery suggested that stars can be influenced by gravitational pull from unseen objects, a concept which extended our understanding of stellar systems and their components.