The Swan
| Abbreviation: | Cyg |
| Genitive: | Cygni |
| Origin: | [antiquity] |
| Fully Visible: | 28°S – 90°N |
There are several swans from Greek mythology identified with this constellation, including Zeus (who disguised himself as a swan to seduce Leda who subsequently gave birth to the Gemini), Orpheus (who was transformed into a swan after his murder), and King Cycnus (who turned into a swan after he was killed by Achilles during the Trojan War).
The asterism composed of the stars α Cyg, β Cyg, γ Cyg, δ Cyg and ε Cyg is often called the 'Northern Cross'. It is not to be confused with the much smaller constellation Crux, the Southern Cross.
The first magnitude star Deneb forms another asterism, the 'Summer Triangle', with two other first magnitude stars, Altair and Vega.
Notable Features
| Visible Named Stars | ||
|---|---|---|
| α Cyg | Deneb | This first magnitude star forms one part of the asterism known as the 'Summer Triangle'. It sometimes appears as Arided (from the Arabic al‑ridf meaning 'the follower') in older star atlases and catalogues. |
| β Cyg | Albireo | Albireo shows up as a beautiful binary star of constrasting colours when viewed through binoculars or a telescope. This star appears as Menchir al Dedjadjet (from the Arabic minqār al‑dajājah meaning 'the beak of the hen') in Mohammad Al Achsasi Al Mouakket's calendarium. |
| γ Cyg | Sadr | This second-magnitude star is classified as a supergiant and is surrounded by a diffuse nebula. |
| δ Cyg | Fawaris | This triple star system has a combined magnitude of +3. |
| ε Cyg | Aljanah | This star sometimes appears as Gienah in older star atlases and catalogues. |
| π¹ Cyg | Azelfafage | This star is a spectroscopic binary with a period of just 26 days. |
| Other Interesting Stars | ||
| 61 Cyg | Just visible to the naked eye, this is one of the closest stars to the Sun and the first one successfully observed for parallax. | |
| Deep Sky Objects | ||
| M29 | This is an open cluster, visible through binoculars. | |
| M39 | Binoculars are also required to see this open star cluster. | |
| C15 | Blinking Planetary | This is a planetary nebula visible through telescopes. The central star is quite bright but averted vision will reveal the nebulosity. Its New General Catalogue number is 6826. |
| C19 | Cocoon Nebula | The Cocoon Nebula requires optical aids to see this seventh magnitude combination emission/reflection nebula with accompanying star cluster. It is also catalogued as IC 5146. |
| C20 | North America Nebula | The North America Nebula (NGC 7000) is so called because in long exposure it takes the outline of the North American continent. |
| C27 | Crescent Nebula | A small telescope should reveal this faint emission nebula. It is also known as NGC 6888. |
| C33, C34 | Veil Nebula | These objects are part of the Cygnus Loop complex, a supernova remnant. The star that blew itself to bits exploded 5000–8000 years ago. The east and west parts of the nebula also appear as NGC 6992 and NGC 6960. |
| Cygnus X‑1 | Probably a black hole, this object is one of the strongest X-ray sources in the sky. | |
| Meteor Shower Radiants | ||
| 012 KCG | κ Cygnids | There are no major meteor showers associated with this constellation. The minor κ Cygnids meteor shower is active during August, peaking in the middle of the month. This is an episodic shower, appearing about every seven years. Its source is unknown. |
Copyright © 1995–2023 by L.M. Stockman and David Harper