During the summer months, we tend to miss the views of Saturn, Jupiter and other heavenly bodies. But it can be a great time to look for others, like globular star clusters, open star clusters, and double stars!

What Are Double Stars?
If you have seen any movies or read any books that refer to having two suns in the sky, that would be a double star system. These star systems typically come in two types – binary and optical doubles. Binary stars are two stars that are gravitationally bound and orbit each other, and optical double stars only appear to be close together when viewed from Earth, but in reality, are not affected by each other’s gravity. Deciphering whether a pair is optical or binary requires observation, and sometimes astronomers aren’t sure whether a pair is one or the other. With a small telescope, even in moderately light polluted skies, summer offers great views of these stellar groupings from the Northern Hemisphere:

• Double Double: also known as Epsilon Lyrae, appears near the constellation Lyra. But with a small telescope, it can be split into ‘two’ stars. A large telescope reveals Epsilon Lyrae’s secret – each of those has a double, plus a fifth star that was discovered in the 1980s!

• Albireo: also known as Beta Cygni, is a gorgeous, likely optical, double star set – one blue, one yellow – in the constellation Cygnus.

• Polaris: while technically a multiple star system, our North Star can easily be separated from one star to two with a modest telescope.

• Mizar and Alcor: located in the handle of the Big Dipper, this pair can be seen with the naked eye. Mizar is actually a double star too, each with a double, and Alcor is also a double!

Aside from looking incredible in a telescope or binoculars, double stars help astronomers learn about measuring the mass of stars and stellar evolution. Overall, these celestial bodies make for excellent targets and are simple crowd pleasers.