Dorado () is a
constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object.
The origins of the e ...
in the southern sky. It was named in the late 16th century and is now one of the
88 modern constellations
In contemporary astronomy, 88 constellations are recognized by the International Astronomical Union (IAU). Each constellation is a region of the sky, bordered by arcs of right ascension and declination. Together they cover the celestial sphere ...
. Its name refers to the
dolphinfish (''Coryphaena hippurus''), which is known as ''dorado'' in
Spanish, although it has also been depicted as a
swordfish
Swordfish (''Xiphias gladius''), also known as broadbills in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are a popular sport fish of the billfish category, though elusive. Swordfis ...
. Dorado contains most of the
Large Magellanic Cloud
The Large Magellanic Cloud (LMC), or Nubecula Major, is a satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (≈160,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the ...
, the remainder being in the constellation
Mensa
Mensa may refer to:
* Mensa International, an organization for people with a high intelligence quotient (IQ)
* Mensa (name), a name and list of people with the given name or surname
* Mensa (constellation), a constellation in the southern sky
* Men ...
. The South
Ecliptic pole also lies within this constellation.
Even though the name Dorado is not
Latin but Spanish, astronomers give it the Latin
genitive
In grammar, the genitive case (abbreviated ) is the grammatical case that marks a word, usually a noun, as modifying another word, also usually a noun—thus indicating an attributive relationship of one noun to the other noun. A genitive can al ...
form ''Doradus'' when naming its stars; it is treated (like the adjacent asterism
Argo Navis) as a feminine proper name of Greek origin ending in -ō (like ''Io'' or ''Callisto'' or ''Argo''), which have a genitive ending ''-ūs''.
History
Dorado was one of twelve constellations named by
Petrus Plancius from the observations of
Pieter Dirkszoon Keyser and
Frederick de Houtman. It appeared:
* On a celestial globe published in 1597 (or 1598) in Amsterdam by Plancius with
Jodocus Hondius
Jodocus Hondius (Latinized version of his Dutch language, Dutch name: ''Joost de Hondt'') (17 October 1563 – 12 February 1612) was a Flemish people, Flemish and Dutch engraving, engraver and cartographer. He is sometimes called Jodocus Hon ...
.
* First depiction in a celestial atlas, in
Johann Bayer
Johann Bayer (1572 – 7 March 1625) was a German lawyer and uranographer (celestial cartographer). He was born in Rain, Lower Bavaria, in 1572. At twenty, in 1592 he began his study of philosophy and law at the University of Ingolstadt, a ...
's ''
Uranometria'' of 1603.
* In
Johannes Kepler
Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws ...
's edition of
Tycho Brahe's star list in the ''
Rudolphine Tables'' of 1627; this was the first time that it was given the alternative name Xiphias, the
swordfish
Swordfish (''Xiphias gladius''), also known as broadbills in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are a popular sport fish of the billfish category, though elusive. Swordfis ...
. The name Dorado ultimately became dominant and was adopted by the IAU.
Dorado represents a
dolphinfish; it has also been called the goldfish because Dorado are gold-colored.
In early 2020,
TOI 700 d, the first
Earth-sized exoplanet was discovered in Dorado by astronomers of the
Transiting Exoplanet Survey Satellite.
Features
Stars
Alpha Doradus is a blue-white star of magnitude 3.3, 176 light-years from Earth. It is the brightest star in Dorado.
Beta Doradus is a notably bright
Cepheid variable star. It is a yellow-tinged supergiant star that has a minimum magnitude of 4.1 and a maximum magnitude of 3.5. One thousand and forty light-years from Earth, Beta Doradus has a period of 9 days and 20 hours.
R Doradus is one of the many
variable stars in Dorado.
S Dor, 9.721
hypergiant in the
Large Magellanic Cloud
The Large Magellanic Cloud (LMC), or Nubecula Major, is a satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (≈160,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the ...
, is the prototype of
S Doradus variable
Luminous blue variables (LBVs) are massive evolved stars that show unpredictable and sometimes dramatic variations in their spectra and brightness. They are also known as S Doradus variables after S Doradus, one of the brightest stars of the Large ...
stars. The variable star
R Doradus 5.73 has the largest-known apparent size of any star other than the Sun.
Gamma Doradus is the prototype of the
Gamma Doradus variable stars.
Supernova 1987A
SN 1987A was a type II supernova in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately from Earth and was the closest observed supernova since Kepler's Supernova. 1987A's light reached Earth on Febr ...
was the closest supernova to occur since the invention of the telescope.
SNR 0509-67.5 is the remnant of an unusually energetic Type 1a supernova from about 400 years ago.
HE 0437-5439 is a
hypervelocity star
In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space.
Stellar kinematics encompasses the measurement of stellar velocities in the Milky Way and its satellites as well as ...
escaping from the
Milky Way/
Magellanic Cloud
The Magellanic Clouds (''Magellanic system'' or ''Nubeculae Magellani'') are two irregular galaxy, irregular dwarf galaxy, dwarf galaxy morphological classification, galaxies in the southern celestial hemisphere. Orbiting the Milky Way galaxy, t ...
system.
Dorado is also the location of the South
Ecliptic pole, which lies near the fish's head. The pole was called "Polus Doradinalis" by
Willem Jansson Blaeu
Willem () is a Dutch and West FrisianRienk de Haan, ''Fryske Foarnammen'', Leeuwarden, 2002 (Friese Pers Boekerij), , p. 158. masculine given name. The name is Germanic, and can be seen as the Dutch equivalent of the name William in English, Gui ...
.
Deep-sky objects
Because Dorado contains part of the
Large Magellanic Cloud
The Large Magellanic Cloud (LMC), or Nubecula Major, is a satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (≈160,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the ...
, it is rich in deep sky objects. The Large Magellanic Cloud, 25,000 light-years in diameter, is a
satellite galaxy of the Milky Way Galaxy, located at a distance of 179,000 light-years. It has been deformed by its gravitational interactions with the larger Milky Way. In 1987, it became host to
SN 1987A, the first supernova of 1987 and the closest since 1604. This 25,000-light-year-wide galaxy contains over 10,000 million stars. All coordinates given are for Epoch
J2000.0.
*
N 180B is an
emission nebula located in the
Large Magellanic Cloud
The Large Magellanic Cloud (LMC), or Nubecula Major, is a satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (≈160,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the ...
.
*
NGC 1566 (
RA 04h 20m 00s
Dec -56° 56.3′) is a face-on spiral galaxy. It gives its name to the
NGC 1566 Group
The Dorado Group is a loose concentration of galaxies containing both spirals and ellipticals. It is generally considered a 'galaxy group' but may approach the size of a 'galaxy cluster'. It lies primarily in the southern constellation Dorado a ...
of galaxies.
*
NGC 1755
NGC 1755 (also known as ESO 56-SC28) is an open star cluster in the Large Magellanic Cloud in the Dorado constellation. It is about 120 light years across and due to its size could be a globular cluster. It has a diameter of 2.6′ and an apparen ...
(RA 04h 55m 13s Dec -68° 12.2′) is a globular cluster.
*
NGC 1763 (RA 04h 56m 49s Dec -68° 24.5′) is a bright nebula associated with three type B stars.
*
NGC 1820 (RA 05h 04m 02s Dec -67° 15.9′) is an open cluster.
*
NGC 1850
NGC 1850 is a double cluster and a super star cluster in the Dorado constellation, located in the northwest part of the bar of the Large Magellanic Cloud, at a distance of from the Sun. It was discovered by Scottish astronomer James Dunlop in 18 ...
(RA 05h 08m 44s Dec -68° 45.7′) is a globular cluster.
*
NGC 1854
NGC 1854 (also known as NGC 1855) is a young globular cluster in the northern part of the central bar structure of the Large Magellanic Cloud in the Dorado constellation. At 200x magnification the cluster appears very bright, large and round, wit ...
(RA 05h 09m 19s Dec -68° 50.8′) is a globular cluster.
*
NGC 1869 (RA 05h 13m 56s Dec -67° 22.8′) is an open cluster.
*
NGC 1901 (RA 05h 18m 15s Dec -68° 26.2′) is an open cluster.
*
NGC 1910 (RA 05h 18m 43s Dec -69° 13.9′) is an open cluster.
*
NGC 1936 (RA 05h 22m 14s Dec -67° 58.7′) is a bright nebula and is one of four NGC objects in close proximity, the others being
NGC 1929
NGC 1929 (also known as ESO 56-EN107) is an open cluster associated with the emission nebula located within the N44 nebula in the Dorado constellation and part of the Large Magellanic Cloud. It was discovered by James Dunlop on August 3, 1826. I ...
,
NGC 1934 and
NGC 1935.
*
NGC 1978
NGC 1978 (also known as ESO 85-SC90) is an elliptical shaped globular cluster or open cluster in the constellation Dorado. It is located within the Large Magellanic Cloud. It was discovered by James Dunlop on November 6, 1826. At an aperture of 50 ...
(RA 05h 28m 36s Dec -66° 14.0′) is an open cluster.
*
NGC 2002 (RA 05h 30m 17s Dec -66° 53.1′) is an open cluster.
*
NGC 2014 (RA 05h 44m 12.7s Dec −67° 42′ 57″) is a red emission nebula.
*
NGC 2020 (RA 05h 44m 12.7s Dec −67° 42′ 57″) is an HII region surrounding a
Wolf–Rayet star.
*
NGC 2027 (RA 05h 35m 00s Dec -66° 55.0′) is an open cluster.
*
NGC 2032
NGC 2032 (also known as ESO 56-EN160 and the Seagull Nebula) is an emission nebula in the Dorado constellation and near the supershell LMC-4 and it consists of NGC 2029, NGC 2035 and NGC 2040. It was first discovered by James Dunlop on 27 Septemb ...
(RA 05h 35m 21s Dec -67° 34.1′; also known as "Seagull Nebula") is a nebula complex that contains four NGC designations:
NGC 2029
NGC 2029 (also known as ESO 56-EN156 or the Dragon's Head Nebula) is an emission nebula in the Dorado constellation and is part of the Large Magellanic Cloud. It is part of a complex of nebulae and stars, including NGC 2032, NGC 2035 and NGC 2040 ...
, NGC 2032,
NGC 2035
NGC 2035 (also known as ESO 56-EN161 and the Dragon's Head Nebula) is an emission nebula and a H II region in the Dorado constellation and part of the Large Magellanic Cloud. It was discovered by James Dunlop on August 3, 1826. Its apparent si ...
and
NGC 2040.
*
NGC 2074
NGC 2074 is a magnitude ~8 emission nebula in the Tarantula Nebula located in the constellation Dorado. It was discovered on 3 August 1826 by James Dunlop
and around 1835 by John Herschel. It is described as being "pretty bright, pretty large ...
(RA 05h 39m 03.0s, Dec −69° 29′ 54″) is an emission nebula.
*
NGC 2080, also called the "Ghost Head Nebula", is an emission nebula that is 50 light-years wide in the Large Magellanic Cloud. It is named for the two distinct white patches that it possesses, which are regions of recent
. The western portion is colored green from
doubly ionized oxygen, the southern portion is red from
hydrogen alpha emissions, and the center region is colored yellow from both oxygen and hydrogen emissions. The western white patch, A1, has one massive, recently formed star inside. The eastern patch, A2, has several stars hidden in its dust.
*
Tarantula Nebula is in the Large Magellanic Cloud, named for its spiderlike shape. It is also designated 30 Doradus, as it is visible to the naked eye as a slightly out-of-focus star. Larger than any nebula in the Milky Way at 1,000 light-years in diameter, it is also brighter, because it is illuminated by the open star cluster
NGC 2070, which has at its center the star cluster
R136. The illuminating stars are
supergiants.
*
NGC 2164 (RA 05h 58m 53s Dec -68° 30.9′) is a globular cluster.
*
N44 is a
superbubble
A superbubble or supershell is a cavity which is hundreds of light years across and is populated with hot (106 K) gas atoms, less dense than the surrounding interstellar medium, blown against that medium and carved out by multiple supern ...
in the Large Magellanic Cloud that is 1,000 light-years wide. Its overall structure is shaped by the 40 hot stars towards its center. Within the superbubble of N44 is a smaller bubble catalogued as N44F. It is approximately 35 light-years in diameter and is shaped by an incredibly hot star at its center, which has a
stellar wind
A stellar wind is a flow of gas ejected from the upper atmosphere of a star. It is distinguished from the bipolar outflows characteristic of young stars by being less collimated, although stellar winds are not generally spherically symmetric.
D ...
speed of 7 million kilometers per hour. N44F also features dust columns with probable
hidden inside.
Equivalents
In
Chinese astronomy, the stars of Dorado are in two of
Xu Guangqi's
Southern Asterisms (近南極星區, ''Jìnnánjíxīngōu''): the
White Patches Attached (夾白, ''Jiābái'') and the
Goldfish (金魚, ''Jīnyú'').
[AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 27 日]
/ref>
Namesakes
* ''Dorado ''(SS-248) and ''Dorado'' (SS-526), two United States Navy submarines, were named after the same sea creature as the constellation.
Gallery
NGC1706 - HST - Potw1943a.tif, NGC 1706 is a spiral galaxy, about 230 million light-years away.
See also
* Dorado in Chinese astronomy
* Dutch celestial cartography in the Age of Exploration
The history of cartography refers to the development and consequences of cartography, or mapmaking technology, throughout human history. Maps have been one of the most important human inventions for millennia, allowing humans to explain and navig ...
* IAU-recognized constellations
References
;Notes
* The above deep sky objects appear in '' Norton's Star Atlas'', 1973 edition.
* Co-ordinates are obtained fro
Uranometria Chart Index
an
Skyview
* Images of the deep sky objects described herein may be viewed a
Skyview
;Citations
Sources
*
*
*
External links
Peoria Astronomical Society - Dorado
{{DEFAULTSORT:Dorado
Southern constellations
Constellations listed by Petrus Plancius
Dutch celestial cartography in the Age of Discovery
Astronomy in the Dutch Republic
1590s in the Dutch Republic