Cygnus Constellation Facts

The area highlighted in yellow is the asterism known as The Northern Cross.

Cygnus is one the most easily recognizable and brightest constellations in the night sky.
The constellation is prominent in the Northern hemisphere but can also be viewed in the Southern hemisphere.
In the Northern hemisphere the constellation can be seen from June to December.
In the Southern hemisphere Cygnus can be viewed low on the northern horizon in the winter months.
The super-giant Deneb is the brightest star in the constellation.
The Northern Cross asterism is a prominent feature of the constellation.
Deneb also features in the Summer Triangle, a bright asterism formed with the stars Vega and Altair.
The North America Nebula is located within the boundaries of the constellation and can be viewed with the naked eye in some areas.
Many exoplanets have been discovered within the boundaries of Cygnus, amongst these is the planet Kepler-22b which may possibly enjoy Earth like conditions.
The star KIC 8462852, also known as Tabby's Star, exists within the constellation of Cygnus. This star exhibits very strange and irregular dimming patterns that have yet to be explained, it has been theorized that a large structure built by an advanced alien civilization is absorbing light from the star although a less exciting explanation is more likely.
Cygnus is the Latin word for swan.

Cygnus Mythology

The constellation is a mythological representation of the swan.

There are several different stories associated with the Cygnus constellation. One story involves the Greek mythological character of Leda who was the Queen of Sparta. As with many ancient Greek myths the amorous advances of the King of Gods Zeus plays a major part in the story. Zeus would often disguise himself as an animal in order to win favour or trick the objects of his affections and this story is no different.

This time his eye was drawn to Leda and he took his chance when one day when she was attacked by an eagle, Zeus disguised himself as a swan and took the queen under his wings. Leda later produced two eggs, with a set of twins being born from each, from each egg one sibling was fathered by Zeus, the other by the King of Sparta. From one egg the brothers Castor and Pollux emerged and from the other the twin sisters Helen of Troy and Clytemnestra were born. To celebrate the births Zeus placed the swan amongst the stars.

Main Stars in the Cygnus Constellation

The number next to each star is its apparent magnitude, its brightness from our point of view on Earth, the lower the number the brighter the star in the night sky.

Deneb
Also known as Alpha Cygni, Deneb lies around 2,500 light years from Earth and is the brightest star in the constellation, this huge star is a blue-white supergiant around 200 times larger in diameter than the sun and is estimated to be around 200,000 times more luminous. Deneb is one of the stars that forms the Summer Triangle, a bright asterism formed with Vega and Altair.

Rukh
Also known as Delta Cygni, Rukh appears as a single star from Earth but is actually a triple star system consisting of a bluish-white giant, along with a yellow-white and orange main sequence stars, the system lies 170 light years from Earth.

Sadr
Also known as Gamma Cygni, Sadr is a very distant star located at a distance of between 1,500 and 2,000 light years from Earth, the star is a bright yellow-white supergiant with a radius 150 times that of the sun,

Gienah
Also known as Epsilon Cygni, Gienah is an orange giant star 170 light years from Earth, it has around twice the mass of the sun and is around 11 times larger in diameter.

Albireo
Also known as Beta Cygni, Albeiro is a double star located around 430 light years from Earth, double stars are two stars that appear close to each other from Earth but may actually be separated by a large distance, the larger of the two stars is an orange giant with a radius around 70 times that of the sun.

Finding Cygnus - Northern Hemisphere

The chart shows the position of Cygnus over most of the United States in late-summer at 10 pm. This chart can also be applied to other areas of the Northern hemisphere such as Canada, the UK and Europe.

In June and July Cygnus will be visible in the north-eastern sky from around 10 pm, by 2 am the constellation will be directly overhead and will stay high in the sky until day break.

From August to September the constellation will appear high in the eastern sky from around 9 pm, staying high in the sky for several hours before heading towards the north-western horizon.

From October to November Cygnus will appear overhead from around 7 pm before gradually dipping towards the north-western horizon over the next few hours.

In December and January it will be visible high in the western sky from around 6 pm before disappearing below the horizon before 10 pm.

Finding Cygnus - Southern Hemisphere

The chart on the left shows the position of Cygnus over most of Australia in early-spring at 8 pm. This chart can also be applied to other areas of the Southern hemisphere such as New Zealand, South Africa and South America. In July and August Cygnus will be visible low in the north-eastern sky from around 9 to 10 pm, staying low on the horizon and moving westwards throughout the night. From September to October the constellation will appear low on the north-eastern horizon from around 7 pm before disappearing below the north-western horizon around midnight.