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Magellanic Clouds

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The Magellanic Clouds ( Magellanic system or Nubeculae Magellani ) are two irregular dwarf galaxies in the southern celestial hemisphere . Orbiting the Milky Way galaxy , these satellite galaxies are members of the Local Group . Because both show signs of a bar structure , they are often reclassified as Magellanic spiral galaxies.

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44-615: The two galaxies are the following: The Magellanic clouds are visible to the unaided eye from the Southern Hemisphere , but cannot be observed from the most northern latitudes . An early possible mention of the Large Magellanic Cloud is in petroglyphs and rock drawings found in Chile . They may be the objects mentioned by the polymath Ibn Qutaybah (d. 889 CE), in his book on Al-Anwā̵’ (the stations of

88-589: A Human Development Index (HDI) of 0.946, the tenth-highest in the world as of the 2024 report. New Zealand is also well developed, with a nominal GDP per capita of US$ 48,072 and an HDI of 0.939, putting it at number 16 in the world in 2024. The least developed nations in the Southern Hemisphere cluster in Africa and Oceania, with Mozambique and Burundi at the lowest ends of the HDI, at 0.461 (number 183 in

132-704: A first approach and we are witnessing the start of a galactic merger that may overlap with the Milky Way's expected merger with the Andromeda Galaxy (and perhaps the Triangulum Galaxy ) in the future. In 2019, astronomers discovered the young star cluster Price-Whelan 1 using Gaia data. The star cluster has a low metallicity and belongs to the leading arm of the Magellanic Clouds. The existence of this star cluster suggests that

176-499: Is about 70% larger than the diameter of the SMC (32,200 ly and 18,900 ly respectively). For comparison, the Milky Way is about 87,400 ly across. The total mass of these two galaxies is uncertain. Only a fraction of their gas seems to have coalesced into stars and they probably both have large dark matter halos. One recent estimate of the total mass of the LMC is about 1/10 that of

220-511: Is due to a past interaction with the LMC splitting the SMC, and that the two sections are still moving apart. They have dubbed this smaller remnant the Mini Magellanic Cloud. This hypothesis was confirmed in 2023. The part of the SMC which is closer to Earth lies 196,000 light-years (60 kiloparsecs) away, whereas the farther part lies 215,000 light-years (66 kiloparsecs) away. Southern Hemisphere The Southern Hemisphere

264-531: Is evidence that the SMC has been in orbit about the LMC for a very long time. The Magellanic system seems most similar to the distinct NGC 3109 system, which is on the edge of the Local Group. Astronomers have long assumed that the Magellanic Clouds have orbited the Milky Way at approximately their current distances, but evidence suggests that it is rare for them to come as close to the Milky Way as they are now. Observation and theoretical evidence suggest that

308-564: Is known that the galaxy has a low metallicity, similar to that to the Small Magellanic Cloud . It is one of the most metal-poor star-forming galaxies in the Local group. NGC 3109 seems to contain an unusually large number of planetary nebulae for its luminosity. It also contains a substantial amount of dark matter . NGC 3109 is located about 1.33 megaparsecs (4.3 Mly) away, in the constellation Hydra . This puts it at

352-483: Is mostly concentrated on/around the islands of Bali , Mauritius , and Fiji . The oldest continuously inhabited city in the Southern Hemisphere is Bogor , in western Java , which was founded in 669 . Ancient texts from the Hindu kingdoms prevalent in the area definitively record 669 CE as the year when Bogor was founded. However, some evidence shows that Zanzibar , an ancient port with around 200,000 inhabitants off

396-648: Is native to Australia but is now also planted in Southern Africa and Latin America for pulp production, and increasingly, biofuel uses. One of the most notable animals to be found almost exclusively in the Southern Hemisphere is the penguin . A species is found around Isabela Island on the Galápagos archipelago in the Pacific Ocean , which straddles the equator. However, most of Isabela and

440-590: Is the half ( hemisphere ) of Earth that is south of the Equator . It contains all or parts of five continents (the whole of Antarctica , the whole of Australia , about 90% of South America , about one-third of Africa , and some islands off the continental mainland of Asia ) and four oceans (the whole Southern Ocean , the majority of the Indian Ocean , the South Atlantic Ocean , and

484-756: Is the vernal equinox and March 20 or 21 is the autumnal equinox. The South Pole is in the centre of the southern hemispherical region. Southern Hemisphere climates tend to be slightly milder than those at similar latitudes in the Northern Hemisphere , except in the Antarctic which is colder than the Arctic . This is because the Southern Hemisphere has significantly more ocean and much less land; water heats up and cools down more slowly than land. The differences are also attributed to oceanic heat transfer and differing extents of greenhouse trapping. In

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528-606: Is true or false." Both Ibn Qutaybah and Al-Sufi were probably quoting from the former's contemporary (and compatriot) and famed scientist Abu Hanifa Dinawari 's mostly lost work on Anwaa. Abu Hanifa was probably quoting earlier sources, which may be just travelers stories, and hence Al-Sufi's comments about their veracity. In Europe , the Clouds were reported by 16th century Italian authors Peter Martyr d'Anghiera and Andrea Corsali , both based on Portuguese voyages. Subsequently, they were reported by Antonio Pigafetta , who accompanied

572-771: The Age of Discovery , the Southern Hemisphere was largely cut off from the cultural constructs of the Western and Eastern worlds . Some view both the West and the East as being Northern Hemisphere-centric concepts. The most widespread religions in the modern Southern Hemisphere are Christianity , prevalent in South America, Africa, Oceania, and East Timor , followed by Islam in East Africa and Indonesia , and Hinduism , which

616-619: The Large Magellanic Cloud but smaller than the Triangulum Galaxy . If it is a spiral galaxy, it would be the smallest in the Local Group . NGC 3109 has a mass of about 2.3 × 10 times the mass of the Sun ( M ☉ ), of which 20% is in the form of neutral hydrogen . It is oriented edge-on from our point of view, and may contain a disk and a halo . The disk appears to be composed of stars of all ages, whereas

660-481: The Norte Chico civilization and Casma–Sechin culture from the northern coast of Peru. These civilizations built cities, pyramids, and plazas in the coastal river valleys of northern Peru with some ruins dating back to 3600 BCE . Easter Island , located about 3,500 kilometres from Chile and French Polynesia , is considered to be the most remote place on Earth to have been permanently inhabited by humans before

704-620: The South Pacific Ocean ), as well as New Zealand and most of the Pacific Islands in Oceania . Its surface is 80.9% water, compared with 60.7% water in the Northern Hemisphere , and it contains 32.7% of Earth's land. Owing to the tilt of Earth's rotation relative to the Sun and the ecliptic plane , summer is from December to February (inclusive) and winter is from June to August (inclusive). September 22 or 23

748-783: The Age of Discovery. It was settled by a Polynesian group known as the Rapa Nui . Areas of the Southern Hemisphere that had no contact with humans before the Age of Discovery include Christmas Island and Mauritius (in the Indian Ocean ), the Galápagos Islands , Juan Fernández Islands and Lord Howe Island (in the South Pacific), the Falkland Islands and Tristan da Cunha (in the South Atlantic ) and

792-494: The Cepheid scales allowed Harlow Shapley to refine the measurement, and these were again revised in 1952 following further research. As of 2023, some astronomers believe the Magellanic Clouds should be renamed, alleging that Magellan was a murderer and neither an astronomer nor the discoverer of the dwarf galaxies. The Large Magellanic Cloud and its neighbour and relative, the Small Magellanic Cloud , are conspicuous objects in

836-486: The Magellanic Clouds from South Africa, writing an 1847 report detailing 919 objects in the Large Magellanic Cloud and 244 objects in the Small Magellanic Cloud. In 1867 Cleveland Abbe suggested that they were separate satellites of the Milky Way. Distances were first estimated by Ejnar Hertzsprung in 1913 using 1912 measurements of Cepheid variables in the SMC by Henrietta Leavitt . Recalibration of

880-413: The Magellanic Clouds have both been greatly distorted by tidal interaction with the Milky Way as they travel close to it. The LMC maintains a very clear spiral structure in radio-telescope images of neutral hydrogen. Streams of neutral hydrogen connect them to the Milky Way and to each other, and both resemble disrupted barred spiral galaxies . Their gravity has affected the Milky Way as well, distorting

924-467: The Milky Way. That would make the LMC rather a large galaxy in the current observable universe. Since the sizes of relatively nearby galaxies are highly skewed, the average mass can be a misleading statistic. In terms of rank, the LMC appears to be the fourth most massive member of over 50 galaxies in the local group. Suggesting that the Magellanic cloud system is historically not a part of the Milky Way

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968-530: The Moon in pre-Islamic Arabian culture): وأسفل من سهيل قدما سهيل . وفى مجرى قدمى سهيل، من خلفهما كواكب زهر كبار، لا ترى بالعراق، يسميها أهل تهامة الأعبار And below Canopus , there are the feet of Canopus, and on their extension, behind them bright big stars, not seen in Iraq , the people of Tihama call them al-a‘bār . Later Al Sufi , a professional astronomer, in 964 CE, in his Book of Fixed Stars , mentioned

1012-591: The Moon moves from right to left during solar eclipses. The Coriolis effect causes cyclones and tropical storms to spin clockwise in the Southern Hemisphere, as opposed to anticlockwise in the Northern Hemisphere. The southern temperate zone , a subsection of the Southern Hemisphere, is nearly all oceanic. The Sagittarius constellation that includes the galactic centre is a southern constellation as well as both Magellanic Clouds . This, combined with clearer skies, makes for excellent viewing of

1056-408: The Southern Hemisphere include Bali , Buenos Aires , Cape Town , Easter Island , Lima , Rio de Janeiro , Sydney and Tahiti . According to a 2017 report, the most popular Southern Hemisphere " bucket list " destinations among Australians were Antarctica , New Zealand , the Galápagos Islands , South Africa and Peru . Quito, Ecuador is the closest major city to the equatorial line on

1100-792: The Southern Hemisphere include São Paulo , where the B3 (stock exchange) is headquartered, along with Sydney, home to the Australian Securities Exchange , Jakarta, the seat of the Indonesia Stock Exchange , Johannesburg , home to the Johannesburg Stock Exchange , and Buenos Aires, headquarters of the Buenos Aires Stock Exchange , the oldest stock market in the Southern Hemisphere. Common tourist destinations in

1144-521: The Southern Hemisphere, the Sun passes from east to west through the north, although north of the Tropic of Capricorn the mean Sun can be directly overhead or due south at midday. The Sun follows a right-to-left trajectory through the northern sky unlike the left-to-right motion of the Sun when seen from the Northern Hemisphere as it passes through the southern sky. Sun-cast shadows turn anticlockwise throughout

1188-524: The coast of Tanzania , may be older than Bogor. A Greco-Roman text written between 1 and 100 CE , the Periplus of the Erythraean Sea , mentioned the island of Menuthias ( Ancient Greek : Μενουθιάς) as a trading port on the east African coast, which is probably the small Tanzanian island of Unguja on which Zanzibar is located. The oldest monumental civilizations in the Southern Hemisphere are

1232-405: The continent of Antarctica . Entirely — Partly — Entirely — Partly — Entirely — Mostly — Partly — Entirely — NGC 3109 NGC 3109 is a small barred Magellanic type spiral or irregular galaxy around 4.35 Mly away in the direction of the constellation of Hydra . NGC 3109 is believed to be tidally interacting with the dwarf elliptical galaxy Antlia Dwarf . It

1276-534: The day and sundials have the hours increasing in the anticlockwise direction. During solar eclipses viewed from a point to the south of the Tropic of Capricorn, the Moon moves from left to right on the disc of the Sun (see, for example, photos with timings of the solar eclipse of November 13, 2012 ), while viewed from a point to the north of the Tropic of Cancer (i.e., in the Northern Hemisphere),

1320-623: The expedition of Ferdinand Magellan on its circumnavigation of the world in 1519–1522. However, naming the clouds after Magellan did not become widespread until much later. In Bayer's Uranometria they are designated as nubecula major and nubecula minor . In the 1756 star map of the French astronomer Lacaille , they are designated as le Grand Nuage and le Petit Nuage ("the Large Cloud" and "the Small Cloud"). John Herschel studied

1364-577: The halo contains only very old and metal-poor stars. NGC 3109 does not appear to possess a galactic nucleus. From measurements of the neutral atomic hydrogen in the galaxy, it has been found that the disk of NGC 3109 is warped. The warp has the same radial velocity as gas in the Antlia Dwarf galaxy, indicating that the two galaxies had a close encounter approximately one billion years ago. Based on spectroscopy of blue supergiants in NGC 3109, it

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1408-516: The largest country by land area in the Southern Hemisphere, while more than 150 million live in Java , the most populous island in the world. The most populous country in the Southern Hemisphere is Indonesia , with 275 million people (roughly 30 million of whom live north of the Equator on the northern portions of the islands of Sumatra , Borneo , and Sulawesi , as well as most of North Maluku , while

1452-475: The leading arm of the Magellanic Clouds is 90,000 light-years away from the Milky Way—closer than previously thought. Astrophysicists D. S. Mathewson, V. L. Ford and N. Visvanathan proposed that the SMC may in fact be split in two, with a smaller section of this galaxy behind the main part of the SMC (as seen from Earth's perspective), and separated by about 30,000 light years. They suggest the reason for this

1496-401: The night sky from the Southern Hemisphere with brighter and more numerous stars. Forests in the Southern Hemisphere have special features which set them apart from those in the Northern Hemisphere. Both Chile and Australia share, for example, unique beech species or Nothofagus , and New Zealand has members of the closely related genera Lophozonia and Fuscospora . The eucalyptus

1540-515: The outer parts of the galactic disk . Aside from their different structure and lower mass, they differ from our galaxy in two major ways. They are gas-rich; a higher fraction of their mass is hydrogen and helium compared to the Milky Way. They are also more metal-poor than the Milky Way; the youngest stars in the LMC and SMC have a metallicity of 0.5 and 0.25 times solar, respectively. Both are noted for their nebulae and young stellar populations , but as in our own galaxy their stars range from

1584-481: The planet, and Ushuaia, Argentina claims the title of world's southernmost city. Cape Town, Christchurch , Hobart , Punta Arenas and Ushuaia are officially acknowledged as the five international Antarctic gateway cities that serve as primary entry points for travel to the Antarctic region. Among the most developed nations in the Southern Hemisphere is Australia, with a nominal GDP per capita of US$ 63,487 and

1628-694: The rest of the archipelago is located in the Southern Hemisphere, and it is deemed by the International Hydrographic Organization as being wholly within the South Pacific Ocean, rather than the North Pacific. More than 850 million people live in the Southern Hemisphere, representing around 10–12% of the total global human population. Of those 850 million people, more than 203 million live in Brazil ,

1672-1057: The rest of the population lives in the Southern Hemisphere). Portuguese is the most spoken language in the Southern Hemisphere, with over 230 million speakers in six countries – mostly in Brazil, but also in Angola , Mozambique , East Timor , and small parts of Equatorial Guinea and São Tomé and Príncipe that lie south of the Equator . Among the largest metropolitan areas in the Southern Hemisphere are Jakarta (34 million people), São Paulo (22 million), Kinshasa-Brazzaville (19 million), Buenos Aires (16 million), Rio de Janeiro (12 million), Johannesburg , Lima (11 million each), Surabaya (10 million), Bandung (9 million), Luanda (8 million), Dar es Salaam , Santiago (7 million each), Belo Horizonte , Semarang (6 million each), Sydney , Melbourne and Cape Town (5 million each). Important financial and commercial centres in

1716-414: The same quote, but with a different spelling. Under Argo Navis , he quoted that "unnamed others have claimed that beneath Canopus there are two stars known as the 'feet of Canopus', and beneath those there are bright white stars that are unseen in Iraq nor Najd , and that the inhabitants of Tihama call them al-Baqar [cows], and Ptolemy did not mention any of this so we [Al-Sufi] do not know if this

1760-549: The southern hemisphere, looking like separated pieces of the Milky Way to the naked eye. Roughly 21 ° apart in the night sky, the true distance between them is roughly 75,000 light-years . Until the discovery of the Sagittarius Dwarf Elliptical Galaxy in 1994, they were the closest known galaxies to our own. The LMC lies about 160,000 light years away, while the SMC is around 200,000. The LMC

1804-449: The very outskirts of the Local Group . Its membership of the Local Group has been questioned, because it seems to be receding faster than estimates of the Local Group's escape velocity . It is distant enough from the largest members of the Local Group that it has not been tidally influenced by them. Although no supernovae have been observed in NGC 3109 yet, a luminous blue variable , designated AT   2018akx (type LBV, mag. 17.5),

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1848-534: The very young to the very old, indicating a long stellar formation history. The Large Magellanic Cloud was the host galaxy to a supernova ( SN 1987A ), the brightest observed in over four centuries. Measurements with the Hubble Space Telescope, announced in 2006, suggest the Magellanic Clouds may be moving too fast to be long term companions of the Milky Way . If they are in orbit, that orbit takes at least 4 billion years. They are possibly on

1892-529: The world) and 0.420 (number 187 in the world), respectively. The nominal GDPs per capita of these two countries do not go above US$ 650, a tiny fraction of the incomes enjoyed by Australians and New Zealanders. The Southern Hemisphere has long been secondary in the global distribution of demographic, economic and political power, as it has less land than the Northern Hemisphere. In recent times, however, countries such as Australia have made greater efforts to economically engage with those from their hemisphere. Before

1936-482: Was discovered by John Herschel on March 24, 1835 while he was in what is now South Africa . NGC 3109 is classified as a Magellanic type irregular galaxy , but it may in fact be a small spiral galaxy . Based on the D 25.5 isophote at the B-band with an angular diameter of 1,980 arcseconds , it has an isophotal diameter approximately 12.80 kiloparsecs (41,700 light-years ) across, slightly larger than

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