Crux is a southern sky constellation centred on four brilliant stars that form a cross-shaped asterism known as the Southern Cross. It is located at the southern end of the visible band of the Milky Way. Crux is a Latin word that means "cross." Crux is one of the easiest constellations to recognise, despite being the smallest of the 88 contemporary constellations. Its four primary stars each have an apparent visual magnitude brighter than +2.8. In many Southern Hemisphere countries and states, it has a strong cultural significance.
Crucis (Acrux) is the brightest and most southerly member of the constellation, with a brightness of 0.8. Crucis (Mimosa), Crucis (Gacrux), and Crucis (Gacrux) are the three other stars of the cross that appear clockwise and in decreasing magnitude (Imai). Cross asterism also contains Crucis (Ginan). Many of the brighter stars belong to the Scorpius–Centaurus Association, a huge but loose collection of hot blue-white stars that appear to have similar origins and motions across the Milky Way's southern reaches. Crux has four Cepheid variables, each of which may be seen with the naked eye under ideal conditions. On Crux's eastern edge is the bright and colourful open cluster known as the Jewel Box (NGC 4755). The Coalsack Nebula is a massive dark nebula spanning 7° by 5° to the southeast, with sections recorded in the surrounding constellations of Centaurus and Musca. |
History and Mythology
The Ancient Greeks were aware of the bright stars in Crux, which Claudius Ptolemy included in the constellation Centaurus. (Staal 1988) In the fourth millennium BC, they were completely visible as far north as Britain. The precession of the equinoxes, on the other hand, progressively dropped the stars below the European horizon, and the inhabitants of northern latitudes eventually forgot about them. (Ridpath & Tirion 2017) By 400 CE, most of Europe had never seen the stars in the constellation now known as Crux rise above the horizon. Dante, who mentions an asterism of four bright stars in the southern sky in his Divine Comedy, may have known of the constellation in the 14th century. (Walker 1881) His depiction, on the other hand, could be symbolic, and the constellation's resemblance a coincidence. (Alighieri 2003) On exiting the Gambia River in 1455, Venetian navigator Alvise Cadamosto noted what was most likely the Southern Cross, naming it the carro dell'ostro ("southern chariot"). Cadamosto's accompanying diagram, on the other hand, was incorrect. (Dekker 1990) Historians attribute João Faras as being the first European to accurately picture it. Faras painted and described the constellation (dubbed "As Guardas") in a letter to the Portuguese ruler written on the beaches of Brazil on May 1, 1500. (Dekker 1990) On his second expedition in 1501–1502, explorer Amerigo Vespucci appears to have seen not only the Southern Cross but also the nearby Coalsack Nebula. (Dekker 1990) Andrea Corsali, an Italian sailor who travelled to China and the East Indies on an expedition financed by King Manuel I from 1515 to 1517, is credited with another early modern report explicitly distinguishing Crux as a separate constellation. Corsali wrote a letter to the monarch in 1516 describing his observations of the southern sky, which included a crude map of the stars around the south celestial pole, including the Southern Cross and the two Magellanic Clouds seen in an external orientation, as on a globe, and a rather crude map of the stars around the south celestial pole, including the Southern Cross and the two Magellanic Clouds. (Dekker 1990) The earliest uranographers (sky mappers) to recognise Crux as a separate constellation were Emery Molyneux and Petrus Plancius, both of whom depicted it in 1592, the former on his celestial globe and the latter in one of the little celestial charts on his great wall map. Both authors, on the other hand, relied on shaky sources and put Crux in the wrong spot. Crux was first depicted in its exact position in 1598 and 1600 on the celestial globes of Petrus Plancius and Jodocus Hondius. Frederick de Houtman catalogued its stars separately from Centaurus for the first time in 1603. Jakob Bartsch in 1624 and Augustin Royer in 1679 were the first to use the constellation. Royer is frequently mistakenly credited with being the one who first distinguished Crux. (Staal 1988) |
Various cultures
十字架 (Shi Zi Jià), which means Cross in Chinese, is an asterism made up of the letters γ Crucis, α Crucis, β Crucis and δ Crucis. (Chen 2005)
Crux and the Coalsack are said to represent a possum sitting in a tree (Boorong people of the Wimmera region of northwestern Victoria), a representation of the sky deity Mirrabooka (Quandamooka people of Stradbroke Island), a stingray (Yolngu people of Arnhem Land), or an eagle (Yolngu people of Arnhem Land) in Australian Aboriginal astronomy (Kaurna people of the Adelaide Plains). Gamma Centauri was also found in two Pacific constellations. Gamma Centauri was the handle, and the four stars were the trident of Tagai's Fishing Spear, according to Torres Strait Islanders in modern-day Australia. The four Cross stars were seen by the Aranda people of central Australia as an eagle's talon and Gamma Centauri as its leg. (Staal 1988)
The four primary stars were perceived as the body of a ray by many peoples in the East Indies and Brazil. (Staal 1988) It is known as Bintang Pari and Buruj Pari in Indonesia and Malaysia, respectively ("ray stars"). An old name for the constellation in Vietnam, sao Cá Lit, likewise has an aquatic connotation (the ponyfish star). (Huỳnh 1895)
Gubug pèncèng ("raking hut") or lumbung ("the granary") was the name given to this constellation by the Javanese because of its shape, which resembled that of a raking house. (Daldjoeni 1984)
The Southern Cross (α, β, γ and δ Crucis) is one of the asterisms utilised by Bugis sailors for navigating, known as bintoéng bola képpang, which translates to "incomplete house star" (Kelley et al., 2011).
Mhutonga is the Mori name for the Southern Cross, which is regarded as the anchor (Te Punga) of Tama-waka rereti's (the Milky Way), with the Pointers serving as its rope. It is known in Tonga as Toloa ("duck"); it is shown as a duck flying south with one of his wings (Crucis) injured by a stone thrown at it by Ongo tangata ("two men" and Centauri). Because of its form, the Coalsack is called Humu (meaning "triggerfish"). (Velt 1990) Sumu ("triggerfish") is the name given to the constellation in Samoa due to its rhomboid shape, while Luatagata (Two Men) is the name given to it in Tonga. In the Southern Cross, the Solomon Islanders spotted several figures. A knee protector and a wrist guard were among the items. Knee protection and a net for catching Palolo worms were among the items. The Marshall Islands' neighbours mistook these stars for fish. (Staal 1988) Peninsular Malays regard the Crux as resembling a fish, notably the Scomberomorus, or Tohok as it is known locally. (Nurul 2016)
Melipal, which means "four stars" in Mapudungun, the language of the Patagonian Mapuches, is the name of the Southern Cross. The crux is known as "Chakana" in Quechua, the Inca civilization's language, which means "stair" (chaka, bridge, link; hanan, high, above), but has a complex connotation within Quechua mysticism. The Great Rhea, which includes Centaurus and Circinus as well as the two bright stars, is made up of one foot of Alpha and Beta Crucis. The Great Rhea was a constellation in Brazil's Bororo constellation system. Argentina's Mocov people witnessed a rhea that included Crux's stars. Two dogs, depicted by bright stars in Centaurus and Circinus, fight their rhea. Alpha and Beta Centauri are engraved on the canines' heads. The four primary stars of Crux mark the rhea's body, whereas Gamma Centauri marks its head, and the brilliant stars of Musca mark its feet. (Staal 1988) A vast constellation resembling a bird snare was used by the Bakairi tribe of Brazil. The brilliant stars of Crux, the southern half of Centaurus, Circinus, at least one star in Lupus, the bright stars of Musca, Beta, and the optical double star Delta Chamaeleontis, as well as parts of the stars of Volans and Mensa, were included. (Staal 1988) The Kalapalo people of Brazil's Mato Grosso state saw Crux's stars as Aganagi angry bees emerging from the Coalsack, which they saw as a beehive. (Basso 1987)
The four most visible stars of Crux, namely four Maerua crassifolia trees, are referred to as iggaren by Tuaregs. Dithutlwa, two giraffes - Alpha and Beta Crucis making a male, and Gamma and Delta forming a female – was the name given to the constellation by the Tswana people of Botswana. (Clegg 1986)
十字架 (Shi Zi Jià), which means Cross in Chinese, is an asterism made up of the letters γ Crucis, α Crucis, β Crucis and δ Crucis. (Chen 2005)
Crux and the Coalsack are said to represent a possum sitting in a tree (Boorong people of the Wimmera region of northwestern Victoria), a representation of the sky deity Mirrabooka (Quandamooka people of Stradbroke Island), a stingray (Yolngu people of Arnhem Land), or an eagle (Yolngu people of Arnhem Land) in Australian Aboriginal astronomy (Kaurna people of the Adelaide Plains). Gamma Centauri was also found in two Pacific constellations. Gamma Centauri was the handle, and the four stars were the trident of Tagai's Fishing Spear, according to Torres Strait Islanders in modern-day Australia. The four Cross stars were seen by the Aranda people of central Australia as an eagle's talon and Gamma Centauri as its leg. (Staal 1988)
The four primary stars were perceived as the body of a ray by many peoples in the East Indies and Brazil. (Staal 1988) It is known as Bintang Pari and Buruj Pari in Indonesia and Malaysia, respectively ("ray stars"). An old name for the constellation in Vietnam, sao Cá Lit, likewise has an aquatic connotation (the ponyfish star). (Huỳnh 1895)
Gubug pèncèng ("raking hut") or lumbung ("the granary") was the name given to this constellation by the Javanese because of its shape, which resembled that of a raking house. (Daldjoeni 1984)
The Southern Cross (α, β, γ and δ Crucis) is one of the asterisms utilised by Bugis sailors for navigating, known as bintoéng bola képpang, which translates to "incomplete house star" (Kelley et al., 2011).
Mhutonga is the Mori name for the Southern Cross, which is regarded as the anchor (Te Punga) of Tama-waka rereti's (the Milky Way), with the Pointers serving as its rope. It is known in Tonga as Toloa ("duck"); it is shown as a duck flying south with one of his wings (Crucis) injured by a stone thrown at it by Ongo tangata ("two men" and Centauri). Because of its form, the Coalsack is called Humu (meaning "triggerfish"). (Velt 1990) Sumu ("triggerfish") is the name given to the constellation in Samoa due to its rhomboid shape, while Luatagata (Two Men) is the name given to it in Tonga. In the Southern Cross, the Solomon Islanders spotted several figures. A knee protector and a wrist guard were among the items. Knee protection and a net for catching Palolo worms were among the items. The Marshall Islands' neighbours mistook these stars for fish. (Staal 1988) Peninsular Malays regard the Crux as resembling a fish, notably the Scomberomorus, or Tohok as it is known locally. (Nurul 2016)
Melipal, which means "four stars" in Mapudungun, the language of the Patagonian Mapuches, is the name of the Southern Cross. The crux is known as "Chakana" in Quechua, the Inca civilization's language, which means "stair" (chaka, bridge, link; hanan, high, above), but has a complex connotation within Quechua mysticism. The Great Rhea, which includes Centaurus and Circinus as well as the two bright stars, is made up of one foot of Alpha and Beta Crucis. The Great Rhea was a constellation in Brazil's Bororo constellation system. Argentina's Mocov people witnessed a rhea that included Crux's stars. Two dogs, depicted by bright stars in Centaurus and Circinus, fight their rhea. Alpha and Beta Centauri are engraved on the canines' heads. The four primary stars of Crux mark the rhea's body, whereas Gamma Centauri marks its head, and the brilliant stars of Musca mark its feet. (Staal 1988) A vast constellation resembling a bird snare was used by the Bakairi tribe of Brazil. The brilliant stars of Crux, the southern half of Centaurus, Circinus, at least one star in Lupus, the bright stars of Musca, Beta, and the optical double star Delta Chamaeleontis, as well as parts of the stars of Volans and Mensa, were included. (Staal 1988) The Kalapalo people of Brazil's Mato Grosso state saw Crux's stars as Aganagi angry bees emerging from the Coalsack, which they saw as a beehive. (Basso 1987)
The four most visible stars of Crux, namely four Maerua crassifolia trees, are referred to as iggaren by Tuaregs. Dithutlwa, two giraffes - Alpha and Beta Crucis making a male, and Gamma and Delta forming a female – was the name given to the constellation by the Tswana people of Botswana. (Clegg 1986)
Characteristics
The crux is bounded to the east, north, and west by the constellations Centaurus (which surrounds it on three sides) and Musca, and to the south by the constellations Centaurus and Musca. It is the smallest of the 88 constellations, covering only 68 square degrees and 0.165 percent of the night sky. (Bagnall 2012) The International Astronomical Union chose the three-letter acronym "Cru" for the constellation in 1922. (Russell 1922) A four-segment polygon defines the official constellation borders, which were established by Belgian astronomer Eugène Delporte in 1930.
The right ascension coordinates of these borders are between 11h 56.13m and 12h 57.45m in the equatorial coordinate system, while the declination coordinates are between 55.68° and 64.70°. Its totality is found south of the 25th parallel north for at least a portion of the year.
Crux can be visible in the sky in tropical areas from April to June. Crux is directly opposite Cassiopeia on the celestial sphere; hence it cannot be seen in the sky at the same time as the latter. The crux is circumpolar and so always visible in the sky in this age, south of Cape Town, Adelaide, and Buenos Aires (the 34th parallel south).
Stargazers sometimes confuse Crux with the neighbouring False Cross. The False Cross is larger and dimmer, lacking a fifth star, and lacks the two notable "Pointer Stars" that are close. The Diamond Cross, which is significantly larger and dimmer, is sandwiched between the two.
The crux is bounded to the east, north, and west by the constellations Centaurus (which surrounds it on three sides) and Musca, and to the south by the constellations Centaurus and Musca. It is the smallest of the 88 constellations, covering only 68 square degrees and 0.165 percent of the night sky. (Bagnall 2012) The International Astronomical Union chose the three-letter acronym "Cru" for the constellation in 1922. (Russell 1922) A four-segment polygon defines the official constellation borders, which were established by Belgian astronomer Eugène Delporte in 1930.
The right ascension coordinates of these borders are between 11h 56.13m and 12h 57.45m in the equatorial coordinate system, while the declination coordinates are between 55.68° and 64.70°. Its totality is found south of the 25th parallel north for at least a portion of the year.
Crux can be visible in the sky in tropical areas from April to June. Crux is directly opposite Cassiopeia on the celestial sphere; hence it cannot be seen in the sky at the same time as the latter. The crux is circumpolar and so always visible in the sky in this age, south of Cape Town, Adelaide, and Buenos Aires (the 34th parallel south).
Stargazers sometimes confuse Crux with the neighbouring False Cross. The False Cross is larger and dimmer, lacking a fifth star, and lacks the two notable "Pointer Stars" that are close. The Diamond Cross, which is significantly larger and dimmer, is sandwiched between the two.
Visibility
Crux may be seen from the southern hemisphere at almost any time of the year. During the northern winter and spring, it is also visible near the horizon from tropical latitudes in the northern hemisphere for a few hours each night. For example, at around 10 p.m. in late April, it is visible from Cancun or any other location with a latitude of 25° N or less. (Pasachoff 2000) There are five primary stars in this film. Crux will travel closer to the South Pole in the next millennia due to precession, reaching 67 degrees south declination in the constellation's midsection. Crux will be visible for much of Europe and continental America by the year 14,000 and will extend to North Europe by the year 18,000 since it will be less than 30 degrees south declination. Navigational use The Southern Cross is used for navigation in the Southern Hemisphere in the same manner that Polaris is used in the Northern Hemisphere. Projecting a line from to Crucis (the foot of the crucifix) 4+12 times beyond results in a point near the Southern Celestial Pole (Ridpath & Tirion 2017), which also happens to be where a perpendicular line southward from the east-west axis of Alpha Centauri to Beta Centauri intersects, which are stars with a similar declination to Crux and a similar width to the cross, but higher magnitude. (Grainger 1969) Crux is said to be used by Argentine gauchos in the Pampas and Patagonia for night navigation. Due to their comparable declinations (distance from the pole), Alpha and Beta Centauri are often referred to as the "Southern Pointers" or simply "The Pointers," allowing people to readily find the Southern Cross or Crux constellation. Between Crux and the pole, itself, there are few brilliant stars, though the constellation Musca can be seen immediately south of Crux. (Grainger 1969) |
Symbols and flags
Crux has long served as a national or unique symbol for several southern countries and organisations. On the flags of Australia, Brazil, New Zealand, Papua New Guinea, and Samoa, the four or five brightest stars of Crux appear, heraldically stylised in various ways. They also feature on the flags of Victoria, the Australian Capital Territory, and the Northern Territory in Australia, as well as the flags of Chile's Magallanes Region, Brazil's Londrina, and various Argentine provincial flags and symbols (for example, Tierra del Fuego and Santa Cruz). The Mercosur trading zone's flag has the four brightest stars. Crux can also be found on the Brazilian coat of arms and, as of July 2015, on the Brazilian passport cover. The Order of the Southern Cross emblem and the logo of the Brazilian football team Cruzeiro Esporte Clube both include five stars, and the cross has been used as the name of the Brazilian currency (the cruzeiro from 1942 to 1986 and again from 1990 to 1994). The constellation is depicted on all coins of the current (1998) series of the Brazilian real. The Southern Cross is mentioned in songs and literature, including in the Argentine epic poem Martn Fierro. In the song "No voy en tren," Argentinian singer Charly Garca declares that he is "from the Southern Cross." In the Brazilian National Anthem (1909), the Cross is mentioned: "A imagem do Cruzeiro resplandece" ("the image of the Cross shines"). The Australian National Anthem mentions the Southern Cross: "Beneath our brilliant Southern Cross, we'll toil with hearts and hands." The coat of arms of William Birdwood, 1st Baron Birdwood, the British general who led the Australian and New Zealand Army Corps during the Gallipoli Campaign of World War One, includes the Southern Cross. The Samoan National Anthem also mentions the Southern Cross. "Vaai I na fetu o lo'u an agiagia ai: Le faailoga lea o Iesu, na maliu ai mo Samoa," says one of the characters. ("Look at those waving stars: This is the sign of Jesus, who died for Samoa on it.") "Beneath the Southern Cross" was a musical song on the NBC television series Victory at Sea, which aired from 1952 to 1953. Crosby, Stills, and Nash released the single "Southern Cross" in 1981. In late 1982, it peaked at #18 on the Billboard Hot 100. Black Sabbath's song "The Sign of the Southern Cross" was released in 1981. On the album "Mob Rules," the song was published. The Order of the Southern Cross is a chivalric order in Brazil that is bestowed on "those who have done great service to the Brazilian country." The Southern Cross is mentioned in the lyrics of "O Sweet Saint Martin's Land": The night is thy Southern Cross. The Australian Eureka Flag features a stylised representation of Crux. The constellation was also featured on the dark blue, shield-like patch worn by personnel of the United States Army's Americal Division, which was based in the Southern Hemisphere on the island of New Caledonia, as well as the blue diamond of the United States 1st Marine Division, which fought on the Southern Hemisphere islands of Guadalcanal and New Britain. The German East Africa Company's Petersflagge flag, which featured a constellation of five white five-pointed Crux "stars" on a red ground from 1885 to 1920, later served as a model for symbolism associated with generic German colonial-oriented organisations, such as the Reichskolonialbund from 1936 to 1943 and the Friends of the former German Protectorates from 1956 to the present. The Southern Cross station in Melbourne, Australia, is an important rail terminal. The Personal Ordinariate of Our Lady of the Southern Cross is a Roman Catholic personal ordinariate for communities of Anglicans seeking full communion with the Catholic Church in Australia and Asia, primarily within the area of the Australian Catholic Bishops Conference. The Knights of the Southern Cross (KSC) is an Australian Catholic fraternal order. |
Deep-sky Objects
Coalsack Nebula – Dark Nebula (viewable to the naked eye)
NGC 4755 – The Jewel box – Open Cluster
NGC 4337 – Open Cluster
NGC 4439 – Open Cluster
NGC 4349 – Open Cluster
Main stars - 4
Bayer stars - 19
Stars with planets - 2
Stars brighter than magnitude 3.00 - 5
Stars within 32 Ly - 0
Bordering
constellations
Meteor showers
Coalsack Nebula – Dark Nebula (viewable to the naked eye)
NGC 4755 – The Jewel box – Open Cluster
NGC 4337 – Open Cluster
NGC 4439 – Open Cluster
NGC 4349 – Open Cluster
Main stars - 4
Bayer stars - 19
Stars with planets - 2
Stars brighter than magnitude 3.00 - 5
Stars within 32 Ly - 0
Bordering
constellations
- Centaurus
- Musca
Meteor showers
- Crucids