Another of my favourite constellations for observation, is the northern constellation of Cygnus.
It is known as “the Swan” because of its distinctive cross-shape in the sky. You can imagine it as a flying swan, with wings outstretched.
Cygnus has a declination of 29 degrees so it can be seen high in the sky to the south during the summer, from northerly latitudes. It is also visible to southern hemisphere observers.
Deneb
The brightest star, alpha-Cygni, is called Deneb (“the tail” from the Arabic).
Deneb is one of the brightest stars in our sky, having a magnitude of 1.2, in spite of it being 2000 light years away. Its absolute (or actual) magnitude is -7, which means it is 30,000 times brighter than our Sun.
Deneb is the most distant, first magnitude star.
Albireo
The double star Albireo (beta-Cygni), marks the head of the swan and it is a showpiece of the sky.
Look at it through a small telescope and you will see a pair of stars in contrasting colours. There is an amber star of magnitude 3, together with a blue-green star of magnitude 5. Beautiful!
The Milky Way
Cygnus lies in a particularly rich area of the sky for stars and clusters because we are looking here, into our own galaxy, the Milky Way.
On a dark and clear night, you can see with the unaided eye a “gap” in the Milky Way, to the side of Cygnus, called the “Cygnus Rift” or “Northern Coalsack”. It is not in fact a gap in the stars, but actually a dark area of dust produced by stellar explosions, that obscures our view of stars in this area.
Veil Nebula
Below the left arm (for northern observers) is an area of gas called the Veil Nebula. This is the remains of a supernova, or exploding star, from 30,000 years ago.
It is tricky to see without imaging the area, although you can see it under good conditions using a low-power telescope.
61-Cygni
This is a pair of orange dwarf stars, that are some of the closest stars to us (just 11 light years away). A good target for a small telescope.
The Coathanger
Below Albireo, towards the constellation of Aquila, is another good target for binoculars and small telescopes. It is not technically in Cygnus, but in the constellation of Vulpecula.
The Coathanger is a cluster of stars and the brightest ones, look just like an inverted coathanger.
Summary
For observers in the Northern hemisphere, the constellation of Cygnus make an interesting observation area. It is high in the sky, so you can see nice sights, even if the sky is not particularly dark.
