The constellation Lyra has become one of my favourite constellations in the sky. It is packed with some amazing sights that are easy to see for the beginner. The alpha star, Vega, is the fifth brightest star in the sky and typically the first one you see in a given evening. It forms a great triangle at your zenith (directly overhead) during the summer with Altair and Deneb, two other really bright stars. This asterism is known as the 'Summer Triangle'. Delta Lyrae is a binary star consisting of a blue and yellow star easily contrasted with one another. The famous Ring Nebula situates itself halfway between Beta and Gamma Lyrae and makes itself a very easy target to find in a telescope. Beta and Gamma Lyrae also act as a pointer to the globular cluster known as Messier 56 another great telescopic target. However, one of my favourite targets in Lyra is Epislon Lyrae, the famous double double.
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| Map to Epsilon Lyrae |
Epsilon Lyrae is one of the most exciting multiple star systems that can be viewed from Earth. When viewed through binoculars or a small telescope the pair is easily split. However, when viewed carefully with a larger telescope, each of the stars in the pairs are shown to be pairs as well. This is why the multiple star system is known as the double-double.
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| Epsilon Lyrae Observation Record |
Epsilon 1 Lyrae and Epsilon 2 Lyraes are separated by about 0.16 light years with an orbital period of several hundred thousand years. When viewed from Earth they have an angular separation of 3.6'. The pair of stars forming Epislon 1 Lyrae and Epsilon 2 Lyrae are approximately 120 times the distance between the Sun and the Earth apart. The angular separation visible from Earth is approximately 2.5" which is very close to the resolving limit of most backyard telescopes with good seeing. If you see the double double on a given night it means the atmospheric disturbance is quite low and you will have a great night of stargazing.
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