What is the constellation Cygnus?
The Cisne (Cygnus) is a constellation in the northern hemisphere. It was one of the 48 constellations described by Ptolemy in his Almagest. Sometimes it is known by the name of the Northern Cross (in reference to the Southern Cross), since its stars form a large cross.
The bird opens its wings over the Milky Way, as if flying towards the south.
Cygnus Constellation: Main Stars
Deneb, α Cygni
Deneb, α Cygni, is a very bright star, prominent despite the distance (1,800 to 3,200 light-years), of magnitude 1.25, it is the 19th brightest star, and one of the farthest visible comets from Earth, 200 times larger than the Sun, it is one of the largest known, and will end in a supernova in a million years. The uncertainty in its position is due to the uncertainty in the parallax for these distances. Its absolute magnitude is around -8.7. This blue supergiant forms the tail of the swan (Deneb is an Arabic name meaning the tail). The top of the Northern Cross, and one of the vertices of the asterism known as the Summer Triangle, contains Vega (α Lyrae) and Altair (α Aquilae).
Albireo, β Cygni
Albireo, β Cygni, is the ‘swan’s beak’ (its name comes from an Arabic word that means the same thing). It is one of the most beautiful double stars, with a golden star (magnitude 3.08) easily distinguishable with a small telescope from its blue companion (magnitude 5.11). They orbit in 7,300 years and the brightest is itself a double, composed of a yellow giant and a main sequence star very close to each other. The blue star rotates rapidly on its own, so it is surrounded by gas that comes from its own surface.
Other stars
Another interesting star is 61 Cygni. This star is one of the closest to the solar system, at 11.4 light-years.
Cygnus OB2 12 It is one of the most luminous comets known.
The star 16 Cygni B forms an extrasolar planetary system, with a confirmed planet 1.5 times the mass of Jupiter.
Cygnus contains an x-ray source in Cygnus X-1which is considered one of the main candidates for being a black hole.
It should also be said that Cygnus contains numerous variable stars, including XX Cyg, and V508 Cyg.
Notable Cygnus Deep Sky Objects
Cygnus, due to its position relative to the Milky Way, is home to many star clusters and nebulae. We find the open clusters M29 and M39.
NGC 7000, the North America Nebula, is located slightly east of Deneb. Its resemblance to the continent can be seen very well in the photographs.
Near Sadr is Cygnus A, one of the most powerful radio sources known. It is a radio galaxy resulting from a massive explosion or a collision with another galaxy.
History and Mythology of Cygnus
Described by Greek astronomers, this constellation was known as the Bird. It was also designated the Cross of Saint Helena by the monk Julius Schiller in 1627, at the time of the counter-reformation, seeking the massive Christianization of heaven (the constellation of the Southern Cross is contemporary).
This constellation can represent many legends of Greek mythology: according to one legend, the god Zeus transformed into a swan to seduce Leda, so she gave birth to the twins and Helen of Troy. It could also represent Orpheus, metamorphosed into a swan after his murder and placed in the sky that devours his Lyre. Finally, it should also be mentioned that, according to another fable, this constellation represents Phaethon’s young lover. Phaethon was struck down by Zeus when he lost control of the chariot of the Sun, and fell into the river Eridanus, and his lover cried so much that Zeus transformed him into a water bird named after him: Swan.