92-548: Pyxis is a small and faint constellation in the southern sky. Abbreviated from Pyxis Nautica , its name is Latin for a mariner's compass (contrasting with Circinus , which represents a draftsman's compasses ). Pyxis was introduced by Nicolas-Louis de Lacaille in the 18th century, and is counted among the 88 modern constellations . The plane of the Milky Way passes through Pyxis. A faint constellation, its three brightest stars— Alpha , Beta and Gamma Pyxidis —are in
184-425: A celestial coordinate system lies in one of the modern constellations. Some astronomical naming systems include the constellation where a given celestial object is found to convey its approximate location in the sky. The Flamsteed designation of a star, for example, consists of a number and the genitive form of the constellation's name. Other star patterns or groups called asterisms are not constellations under
276-459: A polygon of eight sides ( illustrated in infobox ). In the equatorial coordinate system , the right ascension coordinates of these borders lie between 8 27.7 and 9 27.6 , while the declination coordinates are between −17.41° and −37.29°. Lacaille gave Bayer designations to ten stars now named Alpha to Lambda Pyxidis, skipping the Greek letters iota and kappa. Although a nautical element,
368-672: A starburst galaxy due to very high rates of star formation, it has a bluish colour due to the huge numbers of young stars within it. Constellation Four views of the constellation Orion : A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellations were likely defined in prehistory . People used them to relate stories of their beliefs, experiences, creation , and mythology . Different cultures and countries invented their own constellations, some of which lasted into
460-463: A 7 billion-year-old star of spectral type G5V that is around 89% as massive as the Sun. A red dwarf of spectral type M2.5V that has around 42% the Sun's mass, Gliese 317 is orbited by two gas giant planets. Around 50 light-years distant from Earth, it is a good candidate for future searches for more terrestrial rocky planets. Pyxis lies in the plane of the Milky Way , although part of the eastern edge
552-427: A binary system with prominent starspot activity, and lies 184 ± 5 light-years away. The system emits X-rays, and analysing the emission curve over time led researchers to conclude that there was a loop of material arcing between the two stars. RZ Pyxidis is another eclipsing binary system, made up of two young stars less than 200,000 years old. Both are hot blue-white stars of spectral type B7V and are around 2.5 times
644-427: A brighter magnitude of 3.31 if not for this. The second brightest star at magnitude 3.97 is Beta Pyxidis, a yellow bright giant or supergiant of spectral type G7Ib-II that is around 435 times as luminous as the Sun, lying 420 ± 10 light-years distant away from Earth. It has a companion star of magnitude 12.5 separated by 9 arcseconds . Gamma Pyxidis is a star of magnitude 4.02 that lies 207 ± 2 light-years distant. It
736-452: A list of 88 constellations with three-letter abbreviations for them. However, these constellations did not have clear borders between them. In 1928, the IAU formally accepted the 88 modern constellations, with contiguous boundaries along vertical and horizontal lines of right ascension and declination developed by Eugene Delporte that, together, cover the entire celestial sphere; this list
828-421: A long tradition of observing celestial phenomena. Nonspecific Chinese star names , later categorized in the twenty-eight mansions , have been found on oracle bones from Anyang , dating back to the middle Shang dynasty . These constellations are some of the most important observations of Chinese sky, attested from the 5th century BC. Parallels to the earliest Babylonian (Sumerian) star catalogues suggest that
920-437: A luminosity approximately 965 times that of the Sun. It is separated by 2.1 arcseconds from a magnitude 10 star. Theta Pyxidis is a red giant of spectral type M1III and semi-regular variable with two measured periods of 13 and 98.3 days, and an average magnitude of 4.71, and is 500 ± 30 light-years distant from Earth. It has expanded to approximately 54 times the diameter of the Sun. Located around 4 degrees northeast of Alpha
1012-580: A rough line. At magnitude 3.68, Alpha is the constellation's brightest star. It is a blue-white star approximately 880 light-years (270 parsecs ) distant and around 22,000 times as luminous as the Sun. Pyxis is located close to the stars that formed the old constellation Argo Navis , the ship of Jason and the Argonauts . Parts of Argo Navis were the Carina (the keel or hull), the Puppis (the stern), and
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#17327654391581104-417: Is T Pyxidis , a binary star system composed of a white dwarf with around 0.8 times the Sun's mass and a red dwarf that orbit each other every 1.8 hours. This system is located around 15,500 light-years away from Earth. A recurrent nova , it has brightened to the 7th magnitude in the years 1890, 1902, 1920, 1944, 1966 and 2011 from a baseline of around 14th magnitude. These outbursts are thought to be due to
1196-585: Is Teaching Astronomy for Development (TAD) program in countries where there is currently very little astronomical education. Another program is named the Galileo Teacher Training Program (GTTP), is a project of the International Year of Astronomy 2009, among which Hands-On Universe that will concentrate more resources on education activities for children and schools designed to advance sustainable global development. GTTP
1288-483: Is a BL Herculis variable ( type II Cepheid ), ranging between apparent magnitudes 7.13 and 7.40 over a period of 1.24 days. Located around 650 light-years distant, it shines with a luminosity approximately 45 times that of the Sun. The closest star to Earth in the constellation is Gliese 318 , a white dwarf of spectral class DA5 and magnitude 11.85. Its distance has been calculated to be 26 light-years, or 28.7 ± 0.5 light-years distant from Earth. It has around 45% of
1380-692: Is a member of the International Science Council , which is composed of international scholarly and scientific institutions and national academies of sciences . The International Astronomical Union is an international association of professional astronomers , at the PhD level and beyond, active in professional research and education in astronomy . Among other activities, it acts as the recognized authority for assigning designations and names to celestial bodies ( stars , planets , asteroids , etc.) and any surface features on them. The IAU
1472-534: Is a member of the International Science Council . Its main objective is to promote and safeguard the science of astronomy in all its aspects through international cooperation. The IAU maintains friendly relations with organizations that include amateur astronomers in their membership. The IAU has its head office on the second floor of the Institut d'Astrophysique de Paris in the 14th arrondissement of Paris . This organisation has many working groups. For example,
1564-498: Is a red giant of spectral type M5III and semi-regular variable that varies between magnitudes 6.09 and 6.51. Its pulsations take place over multiple periods simultaneously of 55.5, 57.9, 86.7, 162.9 and 232.6 days. UZ Pyxidis is another semi-regular variable red giant, this time a carbon star , that is around 3560 times as luminous as the Sun with a surface temperature of 3482 K, located 2116 light-years away from Earth. It varies between magnitudes 6.99 and 7.83 over 159 days. VY Pyxidis
1656-477: Is affiliated with the International Council of Scientific Unions (ICSU), a non-governmental organization representing a global membership that includes both national scientific bodies and international scientific unions. They often encourage countries to become members of the IAU. The Commission further seeks to development, information or improvement of astronomical education. Part of Commission 46,
1748-436: Is also a binary star system. The main star is a white main sequence star of spectral type A4V that is around 1.85 ± 0.05 times as massive as the Sun. Its companion is most likely a red dwarf of spectral type M3V, around 0.3 times as massive as the Sun. The two are very close—possibly only 3 times the diameter of the Sun between them—and orbit each other every 1.15 days. The brighter star is deformed into an egg shape. AK Pyxidis
1840-802: Is also concerned with the effective use and transfer of astronomy education tools and resources into classroom science curricula. A strategic plan for the period 2010–2020 has been published. In 2004 the IAU contracted with the Cambridge University Press to publish the Proceedings of the International Astronomical Union . In 2007, the Communicating Astronomy with the Public Journal Working Group prepared
1932-797: Is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded on 28 July 1919 in Brussels , Belgium and is based in Paris , France . The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. As of May 2024,
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#17327654391582024-520: Is an open cluster of magnitude 8.4 that is visible in binoculars. Discovered in 1995, the Pyxis globular cluster is a 13.3 ± 1.3 billion year-old globular cluster situated around 130,000 light-years distant from Earth and around 133,000 light-years distant from the centre of the Milky Way—a region not previously thought to contain globular clusters. Located in the galactic halo , it was noted to lie on
2116-405: Is an orange giant of spectral type K3III that has cooled and swollen to 3.7 times the diameter of the Sun after exhausting its core hydrogen. Kappa Pyxidis was catalogued but not given a Bayer designation by Lacaille, but Gould felt the star was bright enough to warrant a letter. Kappa has a magnitude of 4.62 and is 560 ± 50 light-years distant. An orange giant of spectral type K4/K5III, Kappa has
2208-466: Is dark, with material obscuring our galaxy arm there. NGC 2818 is a planetary nebula that lies within a dim open cluster of magnitude 8.2. NGC 2818A is an open cluster that lies on line of sight with it. K 1-2 is a planetary nebula whose central star is a spectroscopic binary composed of two stars in close orbit with jets emanating from the system. The surface temperature of one component has been estimated at as high as 85,000 K. NGC 2627
2300-565: Is most visible in the evening sky in February and March. A small constellation, it is bordered by Hydra to the north, Puppis to the west, Vela to the south, and Antlia to the east. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is "Pyx". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by
2392-567: Is situated about 130,000 light-years away in the galactic halo . This region was not thought to contain globular clusters . The possibility has been raised that this object might have escaped from the Large Magellanic Cloud . In ancient Chinese astronomy , Alpha, Beta, and Gamma Pyxidis formed part of Tianmiao , a celestial temple honouring the ancestors of the emperor, along with stars from neighbouring Antlia . The French astronomer Nicolas-Louis de Lacaille first described
2484-586: Is sufficient for approval in any vote, except for Statute revision which requires a two-thirds majority . An equality of votes is resolved by the vote of the President of the Union. Since 1922, the IAU General Assembly meets every three years, except for the period between 1938 and 1948, due to World War II . After a Polish request in 1967, and by a controversial decision of the then President of
2576-645: Is the Suzhou Astronomical Chart , which was prepared with carvings of stars on the planisphere of the Chinese sky on a stone plate; it is done accurately based on observations, and it shows the supernova of the year of 1054 in Taurus. Influenced by European astronomy during the late Ming dynasty , charts depicted more stars but retained the traditional constellations. Newly observed stars were incorporated as supplementary to old constellations in
2668-450: Is the brightest star in the constellation. Located 880 ± 30 light-years distant from Earth, it is a blue-white giant star of spectral type B1.5III that is around 22,000 times as luminous as the Sun and has 9.4 ± 0.7 times its diameter. It began life with a mass 12.1 ± 0.6 times that of the Sun, almost 15 million years ago. Its light is dimmed by 30% due to interstellar dust , so would have
2760-693: The Inca civilization identified various dark areas or dark nebulae in the Milky Way as animals and associated their appearance with the seasonal rains. Australian Aboriginal astronomy also describes dark cloud constellations, the most famous being the "emu in the sky" whose head is formed by the Coalsack , a dark nebula, instead of the stars. Footnotes Citations International Astronomical Union The International Astronomical Union ( IAU ; French : Union astronomique internationale , UAI )
2852-867: The International Central Bureau of Astronomical Telegrams initially seated in Copenhagen , Denmark. The seven initial member states were Belgium, Canada, France, Great Britain, Greece, Japan, and the United States, soon to be followed by Italy and Mexico. The first executive committee consisted of Benjamin Baillaud (President, France), Alfred Fowler (General Secretary, UK), and four vice presidents: William Campbell (US), Frank Dyson (UK), Georges Lecointe (Belgium), and Annibale Riccò (Italy). Thirty-two Commissions (referred to initially as Standing Committees) were appointed at
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2944-564: The KJV , but ‘Ayish "the bier" actually corresponding to Ursa Major. The term Mazzaroth מַזָּרוֹת , translated as a garland of crowns , is a hapax legomenon in Job 38:32, and it might refer to the zodiacal constellations. There is only limited information on ancient Greek constellations, with some fragmentary evidence being found in the Works and Days of the Greek poet Hesiod , who mentioned
3036-797: The Royal Astronomical Society of New Zealand , the Royal Swedish Academy of Sciences , the Russian Academy of Sciences , and the Science Council of Japan , among many others. The sovereign body of the IAU is its General Assembly , which comprises all members. The Assembly determines IAU policy, approves the Statutes and By-Laws of the Union (and amendments proposed thereto) and elects various committees. The right to vote on matters brought before
3128-675: The Zodiac of Dendera ; it remains unclear when this occurred, but most were placed during the Roman period between 2nd to 4th centuries AD. The oldest known depiction of the zodiac showing all the now familiar constellations, along with some original Egyptian constellations, decans , and planets . Ptolemy's Almagest remained the standard definition of constellations in the medieval period both in Europe and in Islamic astronomy . Ancient China had
3220-711: The constellation in French as la Boussole (the Marine Compass) in 1752, after he had observed and catalogued almost 10,000 southern stars during a two-year stay at the Cape of Good Hope . He devised fourteen new constellations in uncharted regions of the Southern Celestial Hemisphere not visible from Europe. All but one honoured instruments that symbolised the Age of Enlightenment . Lacaille Latinised
3312-592: The horizon when viewed from a particular latitude on Earth is termed circumpolar . From the North Pole or South Pole , all constellations south or north of the celestial equator are circumpolar . Depending on the definition, equatorial constellations may include those that lie between declinations 45° north and 45° south, or those that pass through the declination range of the ecliptic (or zodiac ) ranging between 23.5° north and 23.5° south . Stars in constellations can appear near each other in
3404-535: The zodiac (straddling the ecliptic , which the Sun , Moon , and planets all traverse). The origins of the zodiac remain historically uncertain; its astrological divisions became prominent c. 400 BC in Babylonian or Chaldean astronomy. Constellations appear in Western culture via Greece and are mentioned in the works of Hesiod , Eudoxus and Aratus . The traditional 48 constellations, consisting of
3496-458: The "heavenly bodies". Greek astronomy essentially adopted the older Babylonian system in the Hellenistic era , first introduced to Greece by Eudoxus of Cnidus in the 4th century BC. The original work of Eudoxus is lost, but it survives as a versification by Aratus , dating to the 3rd century BC. The most complete existing works dealing with the mythical origins of the constellations are by
3588-520: The 14th century. The Ancient Greek word for constellation is ἄστρον ( astron ). These terms historically referred to any recognisable pattern of stars whose appearance was associated with mythological characters or creatures, earthbound animals, or objects. Over time, among European astronomers, the constellations became clearly defined and widely recognised. In the 20th century, the International Astronomical Union (IAU) recognized 88 constellations . A constellation or star that never sets below
3680-529: The 17,000-year-old cave paintings in Lascaux , southern France, depict star constellations such as Taurus, Orion's Belt, and the Pleiades. However, this view is not generally accepted among scientists. Inscribed stones and clay writing tablets from Mesopotamia (in modern Iraq) dating to 3000 BC provide the earliest generally accepted evidence for humankind's identification of constellations. It seems that
3772-503: The 88 IAU-recognized constellations in this region first appeared on celestial globes developed in the late 16th century by Petrus Plancius , based mainly on observations of the Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman . These became widely known through Johann Bayer 's star atlas Uranometria of 1603. Fourteen more were created in 1763 by the French astronomer Nicolas Louis de Lacaille , who also split
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3864-466: The Assembly varies according to the type of business under discussion. The Statutes consider such business to be divided into two categories: On budget matters (which fall into the second category), votes are weighted according to the relative subscription levels of the national members. A second category vote requires a turnout of at least two-thirds of national members to be valid. An absolute majority
3956-582: The Brussels meeting and focused on topics ranging from relativity to minor planets. The reports of these 32 Commissions formed the main substance of the first General Assembly, which took place in Rome, Italy, 2–10 May 1922. By the end of the first General Assembly, ten additional nations (Australia, Brazil, Czechoslovakia, Denmark, the Netherlands, Norway, Poland, Romania, South Africa, and Spain) had joined
4048-742: The Hellenistic writer termed pseudo-Eratosthenes and an early Roman writer styled pseudo- Hyginus . The basis of Western astronomy as taught during Late Antiquity and until the Early Modern period is the Almagest by Ptolemy , written in the 2nd century. In the Ptolemaic Kingdom , native Egyptian tradition of anthropomorphic figures represented the planets, stars, and various constellations. Some of these were combined with Greek and Babylonian astronomical systems culminating in
4140-504: The IAU as well as those by cultures throughout history are imagined figures and shapes derived from the patterns of stars in the observable sky. Many officially recognized constellations are based on the imaginations of ancient, Near Eastern and Mediterranean mythologies. Some of these stories seem to relate to the appearance of the constellations, e.g. the assassination of Orion by Scorpius, their constellations appearing at opposite times of year. Constellation positions change throughout
4232-662: The IAU, an Extraordinary IAU General Assembly was held in September 1973 in Warsaw , Poland, to commemorate the 500th anniversary of the birth of Nicolaus Copernicus , soon after the regular 1973 GA had been held in Sydney. Sources. Commission 46 is a Committee of the Executive Committee of the IAU, playing a special role in the discussion of astronomy development with governments and scientific academies. The IAU
4324-871: The IAU, and is a "clearinghouse" for all non-planetary or non-moon bodies in the Solar System. The IAU was founded on 28 July 1919, at the Constitutive Assembly of the International Research Council (now the International Science Council ) held in Brussels , Belgium. Two subsidiaries of the IAU were also created at this assembly: the International Time Commission seated at the International Time Bureau in Paris, France, and
4416-1004: The IAU. National members include the Australian Academy of Science , the Chinese Astronomical Society, the French Academy of Sciences , the Indian National Science Academy , the National Academies (United States) , the National Research Foundation of South Africa , the National Scientific and Technical Research Council (Argentina), the Council of German Observatories, the Royal Astronomical Society (United Kingdom),
4508-572: The Navigator in c. 500 BC. The history of southern constellations is not straightforward. Different groupings and different names were proposed by various observers, some reflecting national traditions or designed to promote various sponsors. Southern constellations were important from the 14th to 16th centuries, when sailors used the stars for celestial navigation . Italian explorers who recorded new southern constellations include Andrea Corsali , Antonio Pigafetta , and Amerigo Vespucci . Many of
4600-410: The Sun's mass, yet only 0.15% of its luminosity. WISEPC J083641.12-185947.2 is a brown dwarf of spectral type T8p located around 72 light-years from Earth. Discovered by infrared astronomy in 2011, it has a magnitude of 18.79. Pyxis is home to three stars with confirmed planetary systems—all discovered by Doppler spectroscopy . A hot Jupiter , HD 73256 b , that orbits HD 73256 every 2.55 days,
4692-630: The Union had 85 national members and 12,734 individual members, spanning 90 countries and territories. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy and includes various scientific meetings. The Union is best known for being the leading authority in assigning official names and designations to astronomical objects , and for setting uniform definitions for astronomical principles. It also coordinates with national and international partners, such as UNESCO , to fulfill its mission. The IAU
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#17327654391584784-689: The Union held the NameExoWorlds contests. Starting in 2024, the Union, in partnership with the United Nations , is poised to play a critical role in developing the legislation and framework for lunar industrialization . As of 1 August 2019, the IAU has a total of 13,701 individual members , who are professional astronomers from 102 countries worldwide; 81.7% of individual members are male, while 18.3% are female. Membership also includes 82 national members , professional astronomical communities representing their country's affiliation with
4876-539: The Union's history are well documented. Subsequent history is recorded in the form of reminiscences of past IAU Presidents and General Secretaries. Twelve of the fourteen past General Secretaries in the period 1964–2006 contributed their recollections of the Union's history in IAU Information Bulletin No. 100. Six past IAU Presidents in the period 1976–2003 also contributed their recollections in IAU Information Bulletin No. 104. In 2015 and 2019,
4968-648: The Union, bringing the total membership to 19 countries. Although the Union was officially formed eight months after the end of World War I, international collaboration in astronomy had been strong in the pre-war era (e.g., the Astronomische Gesellschaft Katalog projects since 1868, the Astrographic Catalogue since 1887, and the International Union for Solar research since 1904). The first 50 years of
5060-538: The Vela (the sails). These eventually became their own constellations. In the 19th century, John Herschel suggested renaming Pyxis to Malus (meaning the mast ) but the suggestion was not followed. T Pyxidis , located about 4 degrees northeast of Alpha Pyxidis, is a recurrent nova that has flared up to magnitude 7 every few decades. Also, three star systems in Pyxis have confirmed exoplanets . The Pyxis globular cluster
5152-673: The Working Group for Planetary System Nomenclature (WGPSN), which maintains the astronomical naming conventions and planetary nomenclature for planetary bodies, and the Working Group on Star Names (WGSN), which catalogues and standardizes proper names for stars. The IAU is also responsible for the system of astronomical telegrams which are produced and distributed on its behalf by the Central Bureau for Astronomical Telegrams . The Minor Planet Center also operates under
5244-549: The ancient Chinese system did not arise independently. Three schools of classical Chinese astronomy in the Han period are attributed to astronomers of the earlier Warring States period . The constellations of the three schools were conflated into a single system by Chen Zhuo , an astronomer of the 3rd century ( Three Kingdoms period ). Chen Zhuo's work has been lost, but information on his system of constellations survives in Tang period records, notably by Qutan Xida . The oldest extant Chinese star chart dates to that period and
5336-409: The ancient constellation Argo Navis into three; these new figures appeared in his star catalogue, published in 1756. Several modern proposals have not survived. The French astronomers Pierre Lemonnier and Joseph Lalande , for example, proposed constellations that were once popular but have since been dropped. The northern constellation Quadrans Muralis survived into the 19th century (when its name
5428-492: The bulk of the Mesopotamian constellations were created within a relatively short interval from around 1300 to 1000 BC. Mesopotamian constellations appeared later in many of the classical Greek constellations. The oldest Babylonian catalogues of stars and constellations date back to the beginning of the Middle Bronze Age , most notably the Three Stars Each texts and the MUL.APIN , an expanded and revised version based on more accurate observation from around 1000 BC. However,
5520-420: The celestial equator), and southern constellations Puppis , Vela , Carina , Crux , Centaurus , Triangulum Australe , and Ara . Polaris , being the North Star, is the approximate center of the northern celestial hemisphere. It is part of Ursa Minor , constituting the end of the Little Dipper's handle. From latitudes of around 35° north, in January, Ursa Major (containing the Big Dipper ) appears to
5612-421: The classical configuration of Argo Navis by renaming it Malus the Mast, a suggestion followed by Francis Baily , but Benjamin Gould restored Lacaille's nomenclature. Covering 220.8 square degrees and hence 0.535% of the sky, Pyxis ranks 65th of the 88 modern constellations by area. Its position in the Southern Celestial Hemisphere means that the whole constellation is visible to observers south of 52°N . It
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#17327654391585704-485: The constellation was not an integral part of the old Argo Navis and hence did not share in the original Bayer designations of that constellation, which were split between Carina, Vela and Puppis. Pyxis is a faint constellation, its three brightest stars— Alpha , Beta and Gamma Pyxidis —forming a rough line. Overall, there are 41 stars within the constellation's borders with apparent magnitudes brighter than or equal to 6.5. With an apparent magnitude of 3.68, Alpha Pyxidis
5796-537: The daytime and lower at night, while in winter the reverse is true, for both hemispheres. Due to the Solar System 's 60° tilt, the galactic plane of the Milky Way is inclined 60° from the ecliptic, between Taurus and Gemini (north) and Scorpius and Sagittarius (south and near which the Galactic Center can be found). The galaxy appears to pass through Aquila (near the celestial equator) and northern constellations Cygnus , Cassiopeia , Perseus , Auriga , and Orion (near Betelgeuse ), as well as Monoceros (near
5888-470: The development of today's accepted modern constellations. The southern sky, below about −65° declination , was only partially catalogued by ancient Babylonians, Egyptians, Greeks, Chinese, and Persian astronomers of the north. The knowledge that northern and southern star patterns differed goes back to Classical writers, who describe, for example, the African circumnavigation expedition commissioned by Egyptian Pharaoh Necho II in c. 600 BC and those of Hanno
5980-432: The early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. Naming constellations also helped astronomers and navigators identify stars more easily. Twelve (or thirteen) ancient constellations belong to
6072-399: The early constellations were never universally adopted. Stars were often grouped into constellations differently by different observers, and the arbitrary constellation boundaries often led to confusion as to which constellation a celestial object belonged. Before astronomers delineated precise boundaries (starting in the 19th century), constellations generally appeared as ill-defined regions of
6164-425: The ecliptic), approximating a great circle . Zodiacal constellations of the northern sky are Pisces , Aries , Taurus , Gemini , Cancer , and Leo . In the southern sky are Virgo , Libra , Scorpius , Sagittarius , Capricornus , and Aquarius . The zodiac appears directly overhead from latitudes of 23.5° north to 23.5° south, depending on the time of year. In summer, the ecliptic appears higher up in
6256-445: The form of star charts , whose oldest representation appears on the statue known as the Farnese Atlas , based perhaps on the star catalogue of the Greek astronomer Hipparchus . Southern constellations are more modern inventions, sometimes as substitutes for ancient constellations (e.g. Argo Navis ). Some southern constellations had long names that were shortened to more usable forms; e.g. Musca Australis became simply Musca. Some of
6348-500: The formal definition, but are also used by observers to navigate the night sky. Asterisms may be several stars within a constellation, or they may share stars with more than one constellation. Examples of asterisms include the teapot within the constellation Sagittarius , or the big dipper in the constellation of Ursa Major . The word constellation comes from the Late Latin term cōnstellātiō , which can be translated as "set of stars"; it came into use in Middle English during
6440-410: The mid-18th century when European explorers began traveling to the Southern Hemisphere . Due to Roman and European transmission, each constellation has a Latin name. In 1922, the International Astronomical Union (IAU) formally accepted the modern list of 88 constellations , and in 1928 adopted official constellation boundaries that together cover the entire celestial sphere. Any given point in
6532-466: The name to Pixis [sic] Nautica on his 1763 chart. The Ancient Greeks identified the four main stars of Pyxis as the mast of the mythological Jason 's ship, Argo Navis . German astronomer Johann Bode defined the constellation Lochium Funis, the Log and Line—a nautical device once used for measuring speed and distance travelled at sea—around Pyxis in his 1801 star atlas, but the depiction did not survive. In 1844 John Herschel attempted to resurrect
6624-449: The northeast, while Cassiopeia is the northwest. To the west are Pisces (above the horizon) and Aries. To the southwest Cetus is near the horizon. Up high and to the south are Orion and Taurus. To the southeast above the horizon is Canis Major . Appearing above and to the east of Orion is Gemini : also in the east (and progressively closer to the horizon) are Cancer and Leo. In addition to Taurus, Perseus and Auriga appear overhead. From
6716-602: The numerous Sumerian names in these catalogues suggest that they built on older, but otherwise unattested, Sumerian traditions of the Early Bronze Age . The classical Zodiac is a revision of Neo-Babylonian constellations from the 6th century BC. The Greeks adopted the Babylonian constellations in the 4th century BC. Twenty Ptolemaic constellations are from the Ancient Near East. Another ten have
6808-488: The parts of the southern sky unknown to Ptolemy) by Petrus Plancius (1592, 1597/98 and 1613), Johannes Hevelius (1690) and Nicolas Louis de Lacaille (1763), who introduced fourteen new constellations. Lacaille studied the stars of the southern hemisphere from 1751 until 1752 from the Cape of Good Hope , when he was said to have observed more than 10,000 stars using a refracting telescope with an aperture of 0.5 inches (13 mm). In 1922, Henry Norris Russell produced
6900-455: The pole star include Chamaeleon , Apus and Triangulum Australe (near Centaurus), Pavo , Hydrus , and Mensa . Sigma Octantis is the closest star approximating a southern pole star, but is faint in the night sky. Thus, the pole can be triangulated using the constellation Crux as well as the stars Alpha and Beta Centauri (about 30° counterclockwise from Crux) of the constellation Centaurus (arching over Crux). It has been suggested that
6992-695: The same latitude, in July, Cassiopeia (low in the sky) and Cepheus appear to the northeast. Ursa Major is now in the northwest. Boötes is high up in the west. Virgo is to the west, with Libra southwest and Scorpius south. Sagittarius and Capricorn are southeast. Cygnus (containing the Northern Cross ) is to the east. Hercules is high in the sky along with Corona Borealis . January constellations include Pictor and Reticulum (near Hydrus and Mensa, respectively). In July, Ara (adjacent to Triangulum Australe) and Scorpius can be seen. Constellations near
7084-410: The same plane as the Large Magellanic Cloud and the possibility has been raised that it might be an escaped object from that galaxy. NGC 2613 is a spiral galaxy of magnitude 10.5 which appears spindle-shaped as it is almost edge-on to observers on Earth. Henize 2-10 is a dwarf galaxy which lies 30 million light-years away. It has a black hole of around a million solar masses at its centre. Known as
7176-836: The same stars but different names. Biblical scholar E. W. Bullinger interpreted some of the creatures mentioned in the books of Ezekiel and Revelation as the middle signs of the four-quarters of the Zodiac, with the Lion as Leo , the Bull as Taurus , the Man representing Aquarius , and the Eagle standing in for Scorpio . The biblical Book of Job also makes reference to a number of constellations, including עיש ‘Ayish "bier", כסיל chesil "fool" and כימה chimah "heap" (Job 9:9, 38:31–32), rendered as "Arcturus, Orion and Pleiades" by
7268-542: The size of the Sun. One is around five times as luminous as the Sun and the other around four times as luminous. The system is classified as a Beta Lyrae variable , the apparent magnitude varying from 8.83 to 9.72 over 0.66 days. XX Pyxidis is one of the more-studied members of a class of stars known as Delta Scuti variables —short period (six hours at most) pulsating stars that have been used as standard candles and as subjects to study astroseismology . Astronomers made more sense of its pulsations when it became clear that it
7360-570: The sky, but they usually lie at a variety of distances away from the Earth. Since each star has its own independent motion, all constellations will change slowly over time. After tens to hundreds of thousands of years, familiar outlines will become unrecognizable. Astronomers can predict the past or future constellation outlines by measuring common proper motions of individual stars by accurate astrometry and their radial velocities by astronomical spectroscopy . The 88 constellations recognized by
7452-564: The sky. Today they now follow officially accepted designated lines of right ascension and declination based on those defined by Benjamin Gould in epoch 1875.0 in his star catalogue Uranometria Argentina . The 1603 star atlas " Uranometria " of Johann Bayer assigned stars to individual constellations and formalized the division by assigning a series of Greek and Latin letters to the stars within each constellation. These are known today as Bayer designations . Subsequent star atlases led to
7544-536: The southern hemisphere of the sky based on the knowledge of Western star charts; with this improvement, the Chinese Sky was integrated with the World astronomy. Historically, the origins of the constellations of the northern and southern skies are distinctly different. Most northern constellations date to antiquity, with names based mostly on Classical Greek legends. Evidence of these constellations has survived in
7636-595: The southern sky, which did not depict the traditional stars recorded by ancient Chinese astronomers. Further improvements were made during the later part of the Ming dynasty by Xu Guangqi and Johann Adam Schall von Bell , the German Jesuit and was recorded in Chongzhen Lishu (Calendrical Treatise of Chongzhen period , 1628). Traditional Chinese star maps incorporated 23 new constellations with 125 stars of
7728-411: The white dwarf accreting material from its companion and ejecting periodically. TY Pyxidis is an eclipsing binary star whose apparent magnitude ranges from 6.85 to 7.5 over 3.2 days. The two components are both of spectral type G5IV with a diameter 2.2 times, and mass 1.2 times that of the Sun, and revolve around each other every 3.2 days. The system is classified as a RS Canum Venaticorum variable ,
7820-409: The year due to night on Earth occurring at gradually different portions of its orbit around the Sun. As Earth rotates toward the east, the celestial sphere appears to rotate west, with stars circling counterclockwise around the northern pole star and clockwise around the southern pole star. Because of Earth's 23.5° axial tilt , the zodiac is distributed equally across hemispheres (along
7912-451: The years and centuries to come. The constellations have no official symbols, though those of the ecliptic may take the signs of the zodiac. Symbols for the other modern constellations, as well as older ones that still occur in modern nomenclature, have occasionally been published. The Great Rift, a series of dark patches in the Milky Way, is most visible in the southern sky. Some cultures have discerned shapes in these patches. Members of
8004-525: The zodiac and 36 more (now 38, following the division of Argo Navis into three constellations) are listed by Ptolemy , a Greco-Roman astronomer from Alexandria , Egypt, in his Almagest . The formation of constellations was the subject of extensive mythology , most notably in the Metamorphoses of the Latin poet Ovid . Constellations in the far southern sky were added from the 15th century until
8096-467: Was attached to the Quadrantid meteor shower), but is now divided between Boötes and Draco . A list of 88 constellations was produced for the IAU in 1922. It is roughly based on the traditional Greek constellations listed by Ptolemy in his Almagest in the 2nd century and Aratus ' work Phenomena , with early modern modifications and additions (most importantly introducing constellations covering
8188-595: Was discovered using the CORALIE spectrograph in 2003. The host star is a yellow star of spectral type G9V that has 69% of our Sun's luminosity, 89% of its diameter and 105% of its mass. Around 119 light-years away, it shines with an apparent magnitude of 8.08 and is around a billion years old. HD 73267 b was discovered with the High Accuracy Radial Velocity Planet Searcher (HARPS) in 2008. It orbits HD 73267 every 1260 days,
8280-498: Was finally published in 1930. Where possible, these modern constellations usually share the names of their Graeco-Roman predecessors, such as Orion, Leo, or Scorpius. The aim of this system is area-mapping, i.e. the division of the celestial sphere into contiguous fields. Out of the 88 modern constellations, 36 lie predominantly in the northern sky, and the other 52 predominantly in the southern. The boundaries developed by Delporte used data that originated back to epoch B1875.0 , which
8372-688: Was preserved as part of the Dunhuang Manuscripts . Native Chinese astronomy flourished during the Song dynasty , and during the Yuan dynasty became increasingly influenced by medieval Islamic astronomy (see Treatise on Astrology of the Kaiyuan Era ). As maps were prepared during this period on more scientific lines, they were considered as more reliable. A well-known map from the Song period
8464-406: Was when Benjamin A. Gould first made his proposal to designate boundaries for the celestial sphere, a suggestion on which Delporte based his work. The consequence of this early date is that because of the precession of the equinoxes , the borders on a modern star map, such as epoch J2000 , are already somewhat skewed and no longer perfectly vertical or horizontal. This effect will increase over
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