Delphinus
Encyclopedia
Delphinus is a constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

 in the northern sky, close to the celestial equator
Celestial equator
The celestial equator is a great circle on the imaginary celestial sphere, in the same plane as the Earth's equator. In other words, it is a projection of the terrestrial equator out into space...

. Its name is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 for dolphin
Dolphin
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...

. Delphinus was one of the 48 constellations listed by the 2nd century astronomer Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

, and it remains among the 88 modern constellations recognized by the International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...

. It is one of the smaller constellations, ranked 69th in size.

Delphinus's brightest stars form a distinctive asterism
Asterism (astronomy)
In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...

 that can easily be recognized. It is bordered (clockwise from north) by Vulpecula
Vulpecula
Vulpecula is a faint constellation in the northern sky. Its name is Latin for "little fox", although it is commonly known simply as the fox. It was identified in the seventeenth century, and is located in the middle of the Summer Triangle .-Stars:There are no stars brighter than 4th magnitude in...

 the fox, Sagitta
Sagitta
Sagitta is a constellation. Its name is Latin for "arrow", and it should not be confused with the larger constellation Sagittarius, the archer. Although ancient, it is insignificant, for it has no star brighter than the 4th magnitude and is the third smallest of all constellations...

 the arrow, Aquila
Aquila (constellation)
Aquila is a stellar constellation. Its name is Latin for 'eagle' and it is commonly represented as such. In mythology, Aquila was owned by the Roman god Jupiter and performed many tasks for him....

 the eagle, Aquarius
Aquarius (constellation)
Aquarius is a constellation of the zodiac, situated between Capricornus and Pisces. Its name is Latin for "water-bearer" or "cup-bearer", and its symbol is , a representation of water....

 the water-carrier, Equuleus
Equuleus
Equuleus is a constellation. Its name is Latin for 'little horse', a foal. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations. It is the second smallest of the modern constellations , spanning only 72 square degrees...

 the foal and Pegasus
Pegasus (constellation)
Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations.-Stars:...

 the flying horse.

Stars

The two brightest stars of this constellation, Svalocin (Alpha Delphini) and Rotanev (Beta Delphini), are not, as one might expect, names dating from antiquity, but instead date from a star catalogue of 1814 that was published at the Palermo Observatory in Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

. When read backwards they form the name Nicolaus Venator which is the Latinized version of the name of the assistant director of that observatory at that time, Niccolò Cacciatore (both Cacciatore and Venator mean hunter).
  • α Del
    Alpha Delphini
    Alpha Delphini is a multiple star in the constellation Delphinus. It also has the name Sualocin, which was given to it as a practical joke by the astronomer Niccolò Cacciatore; the name is the Latinized version of his given name, spelled backwards.In Chinese, , meaning Good Gourd, refers to an...

     (Sualocin): B9 IV, 3.77m (multiple star association, with 7 components, of which only the A & G components are the primary, the others only optical)
  • β Del
    Beta Delphini
    Beta Delphini is a binary star in the constellation of Delphinus. As a practical joke, the astronomer Niccolò Cacciatore gave it the name Rotanev, which is a reversal of his Latinized family name, Venator.In Chinese, , meaning Good Gourd, refers to an asterism consisting of β Delphini, α...

     (Rotanev): F5 IV, 4m - 4.9 m (5-star association, of which A & B components are primary, the rest optical)
  • γ Del
    Gamma Delphini
    Gamma Delphini is a binary star system approximately 101 light-years away in the constellation of Delphinus. The star marks one corner of the asterism "Job's Coffin"...

    : one of the finest double stars in the sky.
    • γ1 Del: F7 V, 5.14m
    • γ² Del: K1 IV, 4.27m
  • δ Del
    Delta Delphini
    Delta Delphini is a giant star in the constellation Delphinus.-References:*...

    : A7 IIIp, 4.43m
  • The above mentioned stars form an asterism
    Asterism (astronomy)
    In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...

     called Job's Coffin.
  • ε Del
    Epsilon Delphini
    Epsilon Delphini is a blue-white giant star approximately 358 light-years away in the constellation Delphinus. It has the traditional name Deneb Dulfim , from the Arabic ذنب الدلفين ðanab ad-dulfīn "tail of the dolphin."The term ðanab ad-dulfīn or Dzaneb al Delphin was appeared in the...

     (Deneb Dulfim, or the tail of the Dolphin) is a star of spectral class B6 III with a magnitude of 4
  • R Delphini|R Del: Mira-type variable star with a period of 285.5 days; magnitude range between 7.6 and 13.8
  • ρ Aquilae
    Rho Aquilae
    Rho Aquilae is a star in the constellation Delphinus – it moved across the border from Aquila into Delphinus in 1992. It has the traditional name Tso Ke, from the Mandarin 左旗 zuǒqí meaning "the left flag"....

     moved across the border into Delphinus in 1992

Deep Space Objects

  • NGC 6891: Planetary nebula
    Planetary nebula
    A planetary nebula is an emission nebula consisting of an expanding glowing shell of ionized gas ejected during the asymptotic giant branch phase of certain types of stars late in their life...

    ; 10.5m
  • NGC 6934
    NGC 6934
    NGC 6934 is a globular cluster in the constellation Delphinus, about 50,000 light years distant. It was discovered by William Herschel on .-External links:* — ESA/Hubble Picture of the Week...

    : This globular cluster
    Globular cluster
    A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...

     is of magnitude 9.75
  • NGC 7006
    NGC 7006
    NGC 7006 is a globular cluster in the constellation Delphinus. NGC 7006 resides in the outskirts of the Milky Way. It is about 135.000 light-years away, five times the distance between the Sun and the centre of the galaxy, and it is part of the galactic halo...

    : at a distance of about 185,000 light-years this globular cluster is extremely remote; 11.5m

Mythology

Delphinus is associated with two stories from Greek mythology
Greek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...

.

According to the first one, the Greek god Poseidon
Poseidon
Poseidon was the god of the sea, and, as "Earth-Shaker," of the earthquakes in Greek mythology. The name of the sea-god Nethuns in Etruscan was adopted in Latin for Neptune in Roman mythology: both were sea gods analogous to Poseidon...

 wanted to marry Amphitrite
Amphitrite
In ancient Greek mythology, Amphitrite was a sea-goddess and wife of Poseidon. Under the influence of the Olympian pantheon, she became merely the consort of Poseidon, and was further diminished by poets to a symbolic representation of the sea...

, a beautiful nereid. She, however, wanting to protect her virginity, fled to the Atlas mountains. Her suitor then sent out several searchers, among them a certain Delphinus. Delphinus accidentally stumbled upon her and was able to persuade Amphitrite to accept Poseidon's wooing. Out of gratitude the god placed the image of a dolphin among the stars.

The second story tells of the Greek poet Arion
Arion
Arion was a kitharode in ancient Greece, a Dionysiac poet credited with inventing the dithyramb: "As a literary composition for chorus dithyramb was the creation of Arion of Corinth," The islanders of Lesbos claimed him as their native son, but Arion found a patron in Periander, tyrant of Corinth...

 of Lesbos (7th century BC), a court musician at the palace of Periander, ruler of Corinth. Arion had amassed a fortune during his travels to Sicily and Italy. On his way home from Tarentum
Taranto
Taranto is a coastal city in Apulia, Southern Italy. It is the capital of the Province of Taranto and is an important commercial port as well as the main Italian naval base....

 his wealth caused the crew of his ship to conspire against him. Threatened with death, Arion asked to be granted a last wish which the crew granted: he wanted to sing a dirge. This he did, and while doing so, flung himself into the sea. There, he was rescued by a dolphin which had been charmed by Arion's music. The dolphin carried Arion to the coast of Greece and left.

Equivalents

In Chinese astronomy
Chinese astronomy
Astronomy in China has a very long history, with historians considering that "they [the Chinese] were the most persistent and accurate observers of celestial phenomena anywhere in the world before the Arabs."...

, the stars of Delphinus are located within the Black Tortoise of the North
Black Tortoise (Chinese constellation)
The Black Tortoise is one of the Four Symbols of the Chinese constellations. It is sometimes called the Black Warrior of the North , and is known as Xuanwu in Chinese, Genbu in Japanese, Hyeonmu in Korean and Huyền Vũ in Vietnamese. It represents the north and the winter season...

(北方玄武, Běi Fāng Xuán Wǔ).

Namesakes

USS Delphinus (AF-24)
USS Delphinus (AF-24)
USS Delphinus was built in 1915 as by Workman Clark and Co., Ltd., Belfast, Northern Ireland; acquired by the U.S. Navy 11 August 1942; and commissioned the same day as San Mateo, Lieutenant O. M. Mikkelsen, USNR, in command...

 and USS Delphinus (PHM-1), two United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

Navy ships, are named after the constellation.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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