The Constellation of Cygnus
Cygnus the Swan forms a huge cross in the northern sky with Beta Cygni (the beautiful double star Albiero) at its head and 1st magnitude star Alpha Cygni (Deneb). The wings of the swan are formed by a line from Delta cygnus to Epsilon Cygni.
Cygnus almost appears to be flying along the milky way South West towards Aquilla, the eagle. In a dark site Cygnus against the backdrop of the milky way is a glorious sight. The milky ways great rift starts near Deneb and extends deep into the milky way.
In mythology Cygnus is associated with severally legendary swans. Orpheus was transformed into a swan after his murder, and was said to have been placed in the sky next to his lyre (Lyra, and the King Cycnus was transformed into a swan. Perhaps the most enduring is Zeus who disguised himself as a swan to seduce Leda, who gave birth to the Gemini, Helen of Troy and Clytemnestra.
Cygnus contains many showcase objects that are interesting astronomically as well as visually striking. In fact there are so many objects in and around Cygnus that we have selected only a few:
- M39 is a very large but loose open cluster, situated some 9 degrees east and slightly north of Deneb (Alpha Cygni). Because of its size it is perhaps best viewed in binoculars.
- M29 is slightly less impressive than M39, It is situated near Gamma Cygni in a crowded area of Milky Way. Like M39 it is best viewed at low powers.
Nebulae
Cygnus boasts many wonderful nebulae but to view these visually usually require the use of filters such as UHC (ultra high contrast or ‘nebula filter’) and OIII.
- The North America Nebula, so called because it resembles the shape of North America, is huge (covering more than four times the area of the full moon) and in very dark skies and good transparency, the it possible to see it with the naked eye but a UHC filter will provide the besty view. The North America Nebula and the nearby Pelican Nebula, interstellarcloud of ionized hydrogen. It makes a superb target for astrophotography but needs a wide field of view and a large format CCD!
- The Dumbell Nebula (M27) is a fine deep-sky object and is bright and easy to view in almost any scope. Ok, it is not in Cygnus, it is actually located in Vulpecula but because it is a good telecope object it is worth a mention here.
Other interesting features
Beta Cygni (Albireo) is one of the most beautiful double stars in the night sky; even a small telescope reveals a beautiful golden-yellow and a blue star embedded in the glitter of the milky way. Being a bright star at the foot of the cross makes it a very east target to find.
Image Credit : Hewholooks CCBY-SA3.0 via Wikipedia Commons