by Dave Blane

The Epsilon Lyrae system is a remarkable multiple star system. It is a must see object in the night sky and arguably the finest example of its type.

As a result epsilon Lyrae is one of the most observed multiple star system and makes for a great view in almost any telescope or binoculars, even under the most polluted skies. The two stars, epsilon1 and epsilon2 are separated by 200 arcsec and so are easily resolved with binoculars and it has even been reported that under ideal condition they have been resolved with the naked eye!

But more is in store when 75mm or larger telescope is focused on this pair. It will be seen that each of the pairs is double. ϵ1 consists of two stars of magnitudes 4.7 and 6.2 while ϵ2 has 5.1 and 5.5 magnitude components.

Although the separations are similar, ϵ2 is more easily resolved than ϵ1 because the magnitude difference is smaller for 2 than 1 ( 0.4 vs 1.5mag). Using a 150mm refractor at 240x there was black sky between the components of ϵ2 and, while ϵ1 was also resolved, the image was not as clean.

In 2013 the writer, using a 150mm refractor and Astrometric eyepiece, measured the separation and position angle of epsilon1 to be 2.4”and 340deg and epsilon2 to be 2.4”and 80deg.

                    Sketch of Epsilon Lyrae