Cygnus (constellation)

Pronunciations/, genitive /
Symbolismthe Swan or Northern Cross
Right ascension 20.62h
Area804 sq. deg. (16th)
Main stars9
Stars with planets97
Stars brighter than 3.00m4
Stars within 10.00 pc (32.62 ly)1
Brightest starDeneb (α Cyg) (1.25m)
Messier objects2
Meteor showersOctober Cygnids
Kappa Cygnids
Visible at latitudes between +90° and −40°.
Best visible at 21:00 (9 p.m.) during the month of September.

Cygnus is a northern constellation lying on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan. The swan is one of the most recognizable constellations of the northern summer and autumn, and it features a prominent asterism known as the Northern Cross (in contrast to the Southern Cross). Cygnus was among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.

Cygnus contains Deneb, one of the brightest stars in the night sky and one corner of the Summer Triangle, as well as some notable X-ray sources and the giant stellar association of Cygnus OB2. Cygnus is also known as the Northern Cross. Deneb is the tail star in the constellation and is the Arabic word for "tail." One of the stars of this association, NML Cygni, is one of the largest stars currently known. The constellation is also home to Cygnus X-1, a distant X-ray binary containing a supergiant and unseen massive companion that was the first object widely held to be a black hole. Many star systems in Cygnus have known planets as a result of the Kepler Mission observing one patch of the sky, an area around Cygnus. In addition, most of the eastern part of Cygnus is dominated by the Hercules–Corona Borealis Great Wall, a giant galaxy filament that is the largest known structure in the observable universe, covering most of the northern sky.

History and mythology

Cygnus as depicted in Urania's Mirror, a set of constellation cards published in London c.1825. Surrounding it are Lacerta, Vulpecula and Lyra.

In western-classic astronomy

In Greek mythology, Cygnus has been identified with several different legendary swans. Zeus disguised himself as a swan to seduce Leda, Spartan king Tyndareus's wife, who gave birth to the Gemini, Helen of Troy, and Clytemnestra;[1] 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 Cygnus was transformed into a swan.

The Greeks also associated this constellation with the tragic story of Phaethon, the son of Helios the sun god, who demanded to ride his father's sun chariot for a day. Phaethon, however, was unable to control the reins, forcing Zeus to destroy the chariot (and Phaethon) with a thunderbolt, causing it to plummet to the earth into the river Eridanus. According to the myth, Phaethon's brother, Cygnus, grieved bitterly and spent many days diving into the river to collect Phaethon's bones to give him a proper burial. The gods were so touched by Cygnus's devotion to his brother that they turned him into a swan and placed him among the stars.[2]

In Ovid's Metamorphoses, there are three people named Cygnus, all of whom are transformed into swans. Alongside Cygnus, noted above, he mentions a boy from Tempe who commits suicide when Phyllius refuses to give him a tamed bull that he demands, but is transformed into a swan and flies away. He also mentions a son of Neptune who is an invulnerable warrior in the Trojan War who is eventually defeated by Achilles, but Neptune saves him by transforming him into a swan.

Together with other avian constellations near the summer solstice, Vultur cadens and Aquila, Cygnus may be a significant part of the origin of the myth of the Stymphalian Birds, one of The Twelve Labours of Hercules.[3]

In non-western astronomy

In Hinduism, the period of time or the Muhurta which lasts from 4:24 AM to 5:12 AM is called the "Brahma Muhurta" translating to "The moment of the Universe" and the Star system in correlation is the Cygnus constellation. This is a highly auspicious time to do any task or start the day.

In Polynesia, Cygnus was often recognized as a separate constellation. In Tonga it was called Tuula-lupe, and in the Tuamotus it was called Fanui-tai. Deneb was also often given a name. The name Deneb comes from the Arabic name dhaneb, meaning "tail", from the phrase Dhanab ad-Dajājah, which means “the tail of the hen”.[4] In New Zealand it was called Mara-tea, in the Society Islands it was called Pirae-tea or Taurua-i-te-haapa-raa-manu, and in the Tuamotus it was called Fanui-raro. Beta Cygni was named in New Zealand; it was likely called Whetu-kaupo. Gamma Cygni was called Fanui-runga in the Tuamotus.[5]

Other Languages
azərbaycanca: Qu (bürc)
Bân-lâm-gú: Thian-ngô͘-chō
беларуская: Лебедзь (сузор’е)
беларуская (тарашкевіца)‎: Лебедзь (сузор’е)
dansk: Svanen
Gaeilge: An Eala
galego: Cygnus
客家語/Hak-kâ-ngî: Thiên-ngò-chho
한국어: 백조자리
Bahasa Indonesia: Cygnus
Basa Jawa: Cygnus
Lëtzebuergesch: Cygnus (Stärebild)
македонски: Лебед (соѕвездие)
മലയാളം: ജായര
Bahasa Melayu: Undan (buruj)
Mìng-dĕ̤ng-ngṳ̄: Tiĕng-ngò̤-cô̤
мокшень: Озял
norsk: Svanen
norsk nynorsk: Svana
oʻzbekcha/ўзбекча: Oqqush (yulduz turkumi)
português: Cygnus
Simple English: Cygnus (constellation)
slovenčina: Labuť (súhvezdie)
slovenščina: Labod (ozvezdje)
српски / srpski: Лабуд (сазвежђе)
srpskohrvatski / српскохрватски: Labud (zviježđe)
татарча/tatarça: Аккош йолдызлыгы
українська: Лебідь (сузір'я)
Tiếng Việt: Thiên Nga (chòm sao)
粵語: 天鵝座
中文: 天鹅座