Cygnus

Click a letter for the index

Or search the encyclopaedia:

 

 

Go

 

Large prominent constellation of the northern hemisphere, represented as a swan. Its brightest star is first-magnitude Alpha Cygni or Deneb.

Beta Cygni (Albireo) is a yellow and blue double star, visible through small telescopes. The constellation contains the North America nebula (named after its shape), the Veil nebula (the remains of a supernova that exploded about 50,000 years ago), Cygnus A (apparently a double galaxy, a powerful radio source, and the first radio star to be discovered), and the X-ray source Cygnus X-1, thought to mark the position of a black hole. The area is rich in high-luminosity objects, nebulae, and clouds of obscuring matter. Deneb marks the tail of the swan, which is depicted as flying along the Milky Way. Some of the brighter stars form the Northern Cross, the upright being defined by Alpha, Gamma, Eta, and Beta, and the crosspiece by Delta, Gamma, and Epsilon Cygni.

The prophet Muhammad is said to have used a green banner. Past variants of the flag show two crossed swords. Effective date: 15 March 1973. >>