Seeing Double – Epsilon Lyrae

Seeing Double – Epsilon Lyrae

Seeing Double - Epsilon Lyrae
Image via Janusz Krysiak/Astronomy Sketch of the Day.

 

Seeing Double – Epsilon Lyrae

While working on the Astronomical League Double Star observing program, one of the more challenging objects is Epsilon Lyrae, the famous “Double Double” star. A good pair of binoculars, say around 10 x 50, will show you Epsilon Lyrae as two stars in one. But a telescope reveals that each of the two stars in the Epsilon Lyrae system is, in itself, a double star. That’s why… Epsilon Lyrae is famous for being the Double Double star, a single point of light to the eye that’s really four stars in one. One stellar pair circles around the other stellar pair in an intricate gravitational dance.

Epsilon Lyrae Double-Double
Epsilon Lyrae Double-Double

On the night of 3 September 2013 from a local dark site, I was able to split all four star with my 120mm f/8.3 refractor operating at 167x. You can view the log entry here.

How to find Epsilon Lyrae. Epsilon Lyrae is wonderfully easy to find. It’s not as bright as Vega, the constellation Lyra’s brightest star. It’s not far from Vega on the sky’s dome, though, and Lyra’s brightness, plus the distinctive shape of the constellation Lyra can help you spot Epsilon Lyra.

With the eye, the gap between Vega and Epsilon Lyrae only amounts to the width of your little finger at an arm length away. As a fun bonus, you can see Vega and Epsilon Lyrae in a single binocular field.

Observing double stars gives us the opportunity to observe even when sky conditions are not so perfect. You don’t need the darkest or clearest skies and many double stars can be observed under moderate light pollution.

 

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