The Constellation Directory


"The Swan"


By IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg) [CC-BY-3.0], via Wikimedia Commons

Abbreviation: Cyg
Genitive: Cygni
Constellation family: Hercules
Nearest constellations: Cepheus, Draco, Lacerta, Lyra, Pegasus, and Vulpecula
Right ascension: 20.62h
Declination: 42.03°
Visible between latitudes: +90° and -40°
Square degrees: 804
Luminary: Deneb (Alpha Cygni)
Named stars: Deneb, Sadr, Albireo
Notable deep sky objects: M29, M39, NGC 7000 (North American Nebula), IC 5067 and IC 5070 (Pelican Nebula), Veil Nebula, NGC 6888 (Crescent Nebula), NGC 6946 (Fireworks Galaxy), Cygnus X-1


Cygnus by Johannes Hevelius

By Johannes Hevelius, scanned by Torsten Bronger 2003 April 4 [Public domain], via Wikimedia Commons

Cygnus is a distinctive constellation in the Northern Hemisphere that is best seen in September. Due to its shape, it is occasionally referred to as the Northern Cross.

The brightest star in Cygnus, Deneb, is one of three stars that form an asterism called the Summer Triangle which is visible at northern latitudes during the summer. The other two stars in the Summer Triangle are Altair from Aquila and Vega from Lyra.


There are a large number of stories that involve swans and could relate to Cygnus. In Greek mythology, Cygnus could represent the swan Zeus transformed himself into in order to seduce Leda, the Queen of Sparta and mother of Helen of Troy. Or, Cygnus could represent Queen Cassiopeia's pet swan. There is not a single, particular myth associated with Cygnus.