Epsilon Lyrae

Epsilon Lyrae (ε Lyr, ε Lyrae), also known as the Double Double, is a multiple star system approximately 162 light-years away in the constellation of Lyra.

Star System

The widest two components of the system are easily separated when viewed through binoculars, or even with the naked eye under excellent conditions. The northern component is called ε¹ and the southern one is called ε²; they both lie around 162 light years from Earth and orbit each other. When viewed at higher magnifications, both stars of the binary can be further split into binaries; that is, the system contains two sets of binary stars orbiting each other. Being able to view the components of each is a common benchmark for the resolving power of telescopes, since the individual doubles are so close together: the stars of ε¹ were 2.35 arc-seconds apart in 2006, those of ε² were separated by about the same amount in that year. Since the first high-precision measurements of their orbit in the 1980s, both binaries have moved only a few degrees in position angle.