monthly skyguide, free star charts, constellation star charts, sky guide

Cygnus - the Swan


Mythology - The Eqyptians and Arabs both see this as a hen and not a swan. The Greeks had several myths involving swans. The most famous one has Zeus disguised as a swan to seduce Leda. The ploy was successful and she laid two eggs. Out of the first popped Castor and Helen, out of the second popped Polydeukes and Klytemnestra. Ovid describes the story of Cygnus, brother of Phaëthon, who roamed the land in search of his brother's body when he died following his fall to Earth from the chariot of the sun. Phaëthon's tortured body had fallen into the River Eridanus. Cygnus threw himself into the water and repeatedly dove beneath the surface in search of his brother. In mercy, the gods transformed him into a swan. This asterism is often called the Northern Cross and has Christian connotations.
Stars - Beta cygnii or Albireo (the beak of the Swan) is a beautiful double star famous for its colour contrast. Binoculars or a small telescope shows the stars to be sapphire and topaz. Omicron(2) cygnii (the lower of the two omicron stars) resolves into three stars in binoculars with contrasting colours. Chi cygnii is a Mira type giant star varying between magnitude 3.3 and 14.2 in 410 days. 61 cygni is the “flying star” and has a large proper motion across the sky due to its proximity. It is also a nice binocular double.
Deepsky - Under dark clear skies, you might just be able to pick out the brighter parts of the North America nebula (NGC 7000) in Cygnus with the naked eye or binoculars. There are also two binocular open clusters, M29 and M39, both around 6th magnitude.
Visibility - Cygnus is not far off being circumpolar, but is best seen from August through to October