The constellation Cygnus was named by Erastothenes, a Greek who is famous for calculating the circumference of the Earth by measuring the length of a shadow cast by the Sun on a day when he knew its rays shone directly into the bottom of a well several kilometers away. Cygnus, represented as a flying swan, is also sometimes called the Northern Cross. The brightest apparent magnitude star in the constellation of Cygnus the swan is Deneb. Deneb is one of the three bright stars that make up the asterism of the summer triangle - a prominent feature of the summer and autumn night sky.
The area of the sky represented by the constellation Cygnus contains many variable stars. One of the variable stars in Cygnus is named W Cygni, or W Cyg.