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Cosmology, Astronomy and Abstract Mathematics

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Elsilon Lyrae

epsilon lyrae

Epsilon Lyrae is a nice easy double star you can view in binoculars all year round in northern latitudes. It sits high in the southern sky very close to the bright star Vega, so is relatively easy to find.

Viewed with the naked eye, it’s just a normal looking 5th magnitude star, but point some binoculars at it and it splits into two clearly separated stars. Things get even more interesting if you train a telescope on the pair, as they’ll split again, revealing a pair of double stars!

The main pair are gravitationally bound and orbit each other every 1200 years with a separation of 160AU (or 160 times the distance from Earth to our Sun). The system is approximately 170 light years away.

Double star systems are the norm in our galaxy with over 60% of star systems containing double or multiple stars orbiting each other at various distances. Our Sun, so far as we know, is a lone wanderer.

Simulations of quadruple star systems suggest they’re relatively unstable, and easily disturbed from their rotating reels by the passing tug of galactic neighbours.

Double double.PNG

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The Andromeda Galaxy


Why not try looking at another galaxy? M31, our nearest companion galaxy, is well placed in northern skies, sitting in the East between the W shape of Cassiopeia and the great square of Pegasus.

Under dark skies and away from significant street lighting, you might just be able to see an oval smudge unaided, but pull up a good pair of binoculars and you’ll see much more. A definite central core and perhaps suggestions of surrounding gas and dust lanes.

Although fuzzy and indistinct the appeal of viewing an object like this is the sheer enormity of the distances and time involved. Andromeda is over 2.5 million light years away, and home to billions and billions of stars and companion worlds.

To find it follow the chart below. From the star Mirak in the constellation Andromeda, simply follow a line upwards in the direction of Cassiopeia. As you sweep this area of the sky in binoculars a bright fuzzy patch should glide into view – that’s M31.


Spotting it for the first time can be tricky, so don’t get too frustrated. It might take you a few attempts over several nights.