How to Find the Cygnus Constellation

Northern hemisphere summer constellations.
Northern hemisphere summer skies, looking south.

Carolyn Collins Petersen

The star pattern astronomers know as Cygnus appears high in the sky beginning in July and is still visible late in the year. Its central area is cross-shaped, and that asterism within the constellation is called the Northern Cross. It is one of three constellations that lends a star to the asterism called the Summer Triangle, which is another stargazing feature that is high in the skies during northern hemisphere summer. For gazers in the southern hemisphere who can spot this region of the sky, it's a winter constellation. It's visible to much (but not all) of the southern hemisphere.

summer-triangle.jpg
The Summer Triangle and the constellations that lend their stars to it. Carolyn Collins Petersen

How to Find Cygnus

Locating Cygnus – sometimes called "The Swan" – is fairly easy thanks to the shape of the Northern Cross at its center. If you are in the northern hemisphere, look for the constellation during late July, when it should be almost directly overhead. Once you spot the cross shape, look for the remaining elements of the constellation, which resemble the wings, beak and tail of the swan.

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The constellation Cygnus with Deneb at the tail of the swan (top) and Albireo (the double star) at the nose of the swan (bottom). Carolyn Collins Petersen

The History of Cygnus

The starry shape of Cygnus the Swan has long been known to stargazers. This constellation is one of the original 48 constellations of antiquity. The ancient Greeks featured it in many of their legends. Zeus, king of the gods, turned himself into a swan to attract the attention of a maiden named Leda. In another story, a musician and prophet named Orpheus was murdered, and his memory was honored by placing him and his lyre into the sky near Cygnus. 

This star pattern was also familiar to stargazers in China, India, and the Polynesian Islands. The bright stars were used as wayfinding guideposts for travelers.

The Stars of the Cygnus Constellation

The brightest stars in Cygnus are Deneb (also known as alpha Cygni) and Albireo (also called beta Cygni), which resemble the tail and the beak of the swan, respectively. Albireo is a famous double star that can be spotted using binoculars or a small telescope. The stars have different coloration: one has a bright golden color, while the other has a bluish tint.

The double star Albireo in Cygnus.
Albireo, the double star in the nose of Cygnus the Swan, can be easily seen through binoculars or a small telescope.  Courtesy N.B., via Wikimedia Commons, Attribution-Share Alike 4.0 license.

Cygnus has a great many variable- and multiple-star systems within its boundaries. That's because it lies in the plane of the Milky Way Galaxy. Stargazers with access to dark skies can often spot a glow that resembles clouds in the region around Cygnus. The glow comes from the millions of stars that lie in the galaxy, and is often referred to as a star cloud. 

Astronomers studied the Cygnus region using the Kepler Space Telescope in the search for planets around other stars. They found that the Cygnus constellation has more than a hundred stars that harbor planets, all within about three thousand light-years of the Sun. Some of those stars have multiple planetary systems.  

The Constellation of Cygnus the swan.
The official IAU constellation star chart for Cygnus the Swan. IAU/Sky Publishing.  

Deep Sky Objects in Constellation Cygnus

Cygnus deep sky objects.
The locations of several deep-sky objects in Cygnus. Carolyn Collins Petersen 

Cygnus has several fascinating deep-sky objects within its boundaries. The first, Cygnus X-1, is a binary system, with a black hole slurping up material from a companion star. The system gives off massive amounts of x-rays as the material spirals around the black hole. While it is not possible to see the system without a telescope, it's still fascinating to know it's there.

The constellation also contains many clusters and beautiful nebulae, the most famous of which is the North America Nebula (also known as NGC 7000). Through binoculars, it appears as a faint glow. Dedicated stargazers can also search out the Veil Nebula, which is a huge remnant left over from a supernova explosion that took place more than five thousand years ago. 

The North America Nebula in Cygnus constellation.
The North America Nebula is a favorite target for astrophotographers. It has the shape of the North American continent. Through a telescope, it doesn't look this colorful, but long-exposure photographs bring out details and colors of the different gases.  Luc Viatour/https://lucniz.be.  Used with permission under a Creative Commons Attributi