Back in April we looked at the sky’s most famous double star, the pair of Mizar and Alcor in the bend of the Big Dipper’s Handle. They’re still out and make a good place to start for some summer star splitting. Most people find it relatively easy to split the two. First locate the Big Dipper high in the northwestern sky after 10 o’clock. Now stare directly at Mizar, the brighter of the two stars. Just above it you’ll catch sight of its fainter companion, Alcor.
First find Vega, Lyra’s brightest star. Face east around 10:30 p.m. and look way up high, about six outstretched fists above the horizon. Vega is the standout, bright white star. You can’t miss it.
Vega is high in the eastern sky during late twilight. Look for a faint star to the left of Vega. That’s Epsilon. — created with Stellarium
If the sky is dark enough to see the little parallelogram of four faint stars that form the harp, you’re ready to find our double star challenge, Epsilon Lyrae. Epsilon lies just to the left and slightly below Vega. At first glance, it’s a dim, ordinary star but point your binoculars at it and you’ll easily split it into a neat little pair of pearls — Epsilon 1 and Epsilon 2.
Epsilon, while dim, is easy to find next to the bright star Vega in Lyra. The inset shows
a high power view of Epsilon in a 3" telescope. Each of the Epsilon stars is double again. — Illustration by Bob King
Now the challenge. Can you split Epsilon 1 and 2 with just your naked eye? It’s more than three times closer than Mizar and Alcor. First thing to do is get in a relaxed position. I recommend a lawn chair or just laying on the grass. Once again, stare directly at the star and concentrate. Can you see two yet — one to the upper left, the other lower right?
I’ll never forget the first time I split them. My daughter Maria and I were huddled together on the ground next to a campfire we built on a trip to the Boundary Waters. It was mid-August and the night was getting cold under a pitch black sky. Lyra was overhead so I asked her if she could split Epsilon in two. Her young eyes had no problem. She correctly told me their positions. Well, what the heck. If she could see it that easily, maybe I could. With some effort, I finally saw the two dim points of light nestled together like close-set eyes.
Epsilon Lyrae holds an additional surprise. If you look at it in a small telescope at around 200x, each star is double again! This has earned Epsilon the nickname "The Double Double" among amateur astronomers. On a calm night, the two close, ant-like pairs are nothing short of stunning.
Epsilon is about 162 light years away. The Epsilon 1 pair revolves around one another in 1,200 years, while Epsilon 2 takes 585 years. The two pairs also orbit about each other’s center of gravity in an achingly long time — about half a million years.
The moon visits the Pleiades tomorrow morning June 30 at dawn — created with Stellarium
The weather forecast calls for clear skies tonight. Ideal for splitting Epsilon Lyrae. For the even more adventurous, the moon will tickle the Seven Sisters star cluster (Pleiades) tomorrow morning (June 30) at dawn. Face northeast in the early dawn light to find the delicate crescent moon. The Pleiades will be just to the moon’s right. I think this pairing will be most enjoyable through binoculars and a great way to start the day.