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97-479: Corona Borealis is a small constellation in the Northern Celestial Hemisphere . It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy , and remains one of the 88 modern constellations . Its brightest stars form a semicircular arc. Its Latin name, inspired by its shape, means "northern crown". In classical mythology Corona Borealis generally represented

194-408: A brown dwarf companion about 63 times as massive as Jupiter with a spectral type of L8 was discovered at a distance of 3640 AU from the pair in 2001. Corona Borealis contains few galaxies observable with amateur telescopes. NGC 6085 and 6086 are a faint spiral and elliptical galaxy respectively close enough to each other to be seen in the same visual field through a telescope. Abell 2142

291-447: A dust debris disk, and one planet with a period of 3.4 years. This planet's mass is estimated at 2.5   M J . The dimensions of the debris disk indicate it is likely there is a second substellar companion. Omicron Coronae Borealis is a K-type clump giant with one confirmed planet with a mass of 0.83   M J that orbits every 187 days—one of the two least massive planets known around clump giants. HD 145457

388-656: 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 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

485-575: A handful of cases, Gould numbers are not in common use. Similarly, Flamsteed-like designations assigned by other astronomers (for example, Hevelius ) are no longer in general use. (A well-known exception is the globular cluster 47 Tucanae from Bode 's catalog.) 84 stars entered in Flamsteed's catalog are errors and proved not to exist in the sky: All of them except 11 Vulpeculae were plotted on his star charts. There are 52 constellations that primarily use Flamsteed designations. Stars are listed in

582-452: 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

679-421: 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

776-474: A period of 17.4 days. The primary is a white main-sequence star of spectral type A0V that is 2.91 times the mass of the Sun ( M ☉ ) and 57 times as luminous ( L ☉ ), and is surrounded by a debris disk out to a radius of around 60  astronomical units (AU). The secondary companion is a yellow main-sequence star of spectral type G5V that is a little smaller (0.9 times)

873-423: A period of 357 days, it is located near the junction of the border of Corona Borealis with Hercules and Bootes. Located 1.5° northeast of Tau Coronae Borealis , W Coronae Borealis ranges between magnitudes 7.8 and 14.3 over a period of 238 days. Another red giant, RR Coronae Borealis is a M3-type semiregular variable star that varies between magnitudes 7.3 and 8.2 over 60.8 days. RS Coronae Borealis

970-453: A period of 360 days. Located around 1946 light-years distant, it shines with a luminosity 16,643 times that of the Sun and has a surface temperature of 3033 K. One of the reddest stars in the sky, V Coronae Borealis is a cool star with a surface temperature of 2877 K that shines with a luminosity 102,831 times that of the Sun and is a remote 8810 light-years distant from Earth. Varying between magnitudes 6.9 and 12.6 over

1067-422: A period of approximately 8 months. R Coronae Borealis is a yellow-hued variable supergiant star, over 7000 light-years from Earth, and prototype of a class of stars known as R Coronae Borealis variables . Normally of magnitude 6, its brightness periodically drops as low as magnitude 15 and then slowly increases over the next several months. These declines in magnitude come about as dust that has been ejected from

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1164-421: A planet around 6.7 times as massive as Jupiter ( M J ) orbiting every 418 days at an average distance of around 1.3 AU. Epsilon itself is a 1.7  M ☉ orange giant of spectral type K2III that has swollen to 21  R ☉ and 151  L ☉ . Kappa Coronae Borealis is a spectral type K1IV orange subgiant nearly twice as massive as the Sun; around it lies

1261-520: A preliminary version of John Flamsteed 's Historia Coelestis Britannica published by Edmond Halley and Isaac Newton in 1712 without Flamsteed's approval. The final version of Flamsteed's catalogue published in 1725 after his death omitted the numerical designations altogether. The numbers now in use were assigned by the French astronomer, Joseph Jérôme de Lalande and appeared in his 1783 almanac, Éphémérides des mouvemens célestes which contained

1358-664: A revised edition of Flamsteed's catalogue. Lalande noted in his Introduction that he got the idea from the unofficial 1712 edition. Flamsteed designations gained popularity throughout the eighteenth century, and are now commonly used when no Bayer designation exists. Where a Bayer designation with a Greek letter does exist for a star, it is usually used in preference to the Flamsteed designation. (Flamsteed numbers are generally preferred to Bayer designations with Roman letters.) Examples of well-known stars that are usually referred to by their Flamsteed numbers include 51 Pegasi , and 61 Cygni . Flamsteed designations are often used instead of

1455-661: A single culture or nation. Naming constellations also helped astronomers and navigators identify stars more easily. Twelve (or thirteen) ancient constellations belong to 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

1552-462: A surface temperature of 5180 K. For most of its existence, Delta Coronae Borealis was a blue-white main-sequence star of spectral type B before it ran out of hydrogen fuel in its core. Its luminosity and spectrum suggest it has just crossed the Hertzsprung gap , having finished burning core hydrogen and just begun burning hydrogen in a shell that surrounds the core. Zeta Coronae Borealis

1649-511: Is Theta Coronae Borealis , a binary system that shines with a combined magnitude of 4.13 located 380±20 light-years distant. The brighter component, Theta Coronae Borealis A, is a blue-white star that spins extremely rapidly—at a rate of around 393 km per second. A Be star , it is surrounded by a debris disk. Flanking Alpha to the east is Gamma Coronae Borealis, yet another binary star system, whose components orbit each other every 92.94 years and are roughly as far apart from each other as

1746-414: Is "CrB". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of eight segments ( illustrated in infobox ). In the equatorial coordinate system , the right ascension coordinates of these borders lie between 15 16.0 and 16 25.1 , while the declination coordinates are between 39.71° and 25.54°. It has a counterpart— Corona Australis —in

1843-469: Is a cataclysmic variable star also known as the Blaze Star. Normally placid around magnitude 10—it has a minimum of 10.2 and maximum of 9.9—it brightens to magnitude 2 in a period of hours, caused by a nuclear chain reaction and the subsequent explosion. T Coronae Borealis is one of a handful of stars called recurrent novae , which include T Pyxidis and U Scorpii . An outburst of T Coronae Borealis

1940-499: Is a rapidly oscillating Ap star , pulsating with a period of 16.2 minutes. Of spectral type A5V with a surface temperature of around 7980 K, it has around 2.1  M ☉ , 2.6  solar radii ( R ☉ ), and 25.3  L ☉ . The smaller star is of spectral type F2V with a surface temperature of around 6750 K, and has around 1.4  M ☉ , 1.56  R ☉ , and between 4 and 5  L ☉ . Near Nusakan

2037-441: Is a red giant of spectral type M2III and magnitude 5.2, lying 640±30 light-years distant, and the secondary, Nu Coronae Borealis , is an orange-hued giant star of spectral type K5III and magnitude 5.4, estimated to be 590±30 light-years away. Sigma Coronae Borealis , on the other hand, is a true multiple star system divisible by small amateur telescopes. It is actually a complex system composed of two stars around as massive as

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2134-424: Is a double star with two blue-white components 6.3  arcseconds apart that can be readily separated at 100x  magnification . The primary is of magnitude 5.1 and the secondary is of magnitude 6.0. Nu Coronae Borealis is an optical double , whose components are a similar distance from Earth but have different radial velocities , hence are assumed to be unrelated. The primary, Nu Coronae Borealis ,

2231-436: Is a huge (six million light-year diameter), X-ray luminous galaxy cluster that is the result of an ongoing merger between two galaxy clusters. It has a redshift of 0.0909 (meaning it is moving away from us at 27,250 km/s) and a visual magnitude of 16.0. It is about 1.2 billion light-years away. Another galaxy cluster in the constellation, RX J1532.9+3021 , is approximately 3.9 billion light-years from Earth. At

2328-471: Is an orange giant of spectral type K0III found to have one planet of 2.9   M J . Discovered by the Doppler method in 2010, it takes 176 days to complete an orbit. XO-1 is a magnitude 11 yellow main-sequence star located approximately 560 light-years away, of spectral type G1V with a mass and radius similar to the Sun. In 2006 the hot Jupiter exoplanet XO-1b was discovered orbiting XO-1 by

2425-453: Is another cycle of 112.6 minutes, which corresponds to the orbit of the disk around the degenerate star. The beat period of 5.5 days indicates the time the accretion disk—which is asymmetrical—takes to precess around the star. Extrasolar planets have been confirmed in five star systems, four of which were found by the radial velocity method. The spectrum of Epsilon Coronae Borealis was analysed for seven years from 2005 to 2012, revealing

2522-408: Is around 70% as massive as the Sun, yet has only 1.1% of its diameter. Discovered in 1990, UW Coronae Borealis is a low-mass X-ray binary system composed of a star less massive than the Sun and a neutron star surrounded by an accretion disk that draws material from the companion star. It varies in brightness in an unusually complex manner: the two stars orbit each other every 111 minutes, yet there

2619-532: Is assigned a number and the Latin genitive of the constellation it lies in (see 88 modern constellations for a list of constellations and the genitive forms of their names). Flamsteed designations were assigned to 2554 stars. The numbers were originally assigned in order of increasing right ascension within each constellation, but due to the effects of precession they are now slightly out of order in some places. This method of designating stars first appeared in

2716-645: 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

2813-403: Is the prototype of a rare class of giant stars—the R Coronae Borealis variables —that are extremely hydrogen deficient, and thought to result from the merger of two white dwarfs. T Coronae Borealis , also known as the Blaze Star, is another unusual type of variable star known as a recurrent nova . Normally of magnitude 10, it last flared up to magnitude 2 in 1946, and is predicted to do

2910-442: Is yet another semiregular variable red giant, which ranges between magnitudes 8.7 to 11.6 over 332 days. It is unusual in that it is a red star with a high proper motion (greater than 50 milliarcseconds a year). Meanwhile, U Coronae Borealis is an Algol-type eclipsing binary star system whose magnitude varies between 7.66 and 8.79 over a period of 3.45 days TY Coronae Borealis is a pulsating white dwarf (of ZZ Ceti) type, which

3007-619: The Corona Borealis Supercluster . Another galaxy cluster, Abell 2162 , is a member of the Hercules Superclusters . In Greek mythology , Corona Borealis was linked to the legend of Theseus and the minotaur . It was generally considered to represent a crown given by Dionysus to Ariadne , the daughter of Minos of Crete, after she had been abandoned by the Athenian prince Theseus . When she wore

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3104-479: The Hipparcos satellite subsequently showed it instead to be a low-mass star somewhere between 100 and 200 times the mass of Jupiter. Possible stable planetary orbits in the habitable zone were calculated for the binary star Eta Coronae Borealis , which is composed of two stars—yellow main sequence stars of spectral type G1V and G3V respectively—similar in mass and spectrum to the Sun. No planet has been found, but

3201-726: 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 Flamsteed designation Flamsteed designations for stars are similar to Bayer designations , except that they use numbers instead of Greek and Roman letters. Each star

3298-616: 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

3395-645: The Southern Celestial Hemisphere . The seven stars that make up the constellation's distinctive crown-shaped pattern are all 4th-magnitude stars except for the brightest of them, Alpha Coronae Borealis . The other six stars are Theta , Beta , Gamma , Delta , Epsilon and Iota Coronae Borealis . The German cartographer Johann Bayer gave twenty stars in Corona Borealis Bayer designations from Alpha to Upsilon in his 1603 star atlas Uranometria . Zeta Coronae Borealis

3492-675: 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

3589-592: 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

3686-479: The transit method using the XO Telescope . Roughly the size of Jupiter, it completes an orbit around its star every three days. The discovery of a Jupiter-sized planetary companion was announced in 1997 via analysis of the radial velocity of Rho Coronae Borealis, a yellow main sequence star and Solar analog of spectral type G0V, around 57 light-years distant from Earth. More accurate measurement of data from

3783-458: 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

3880-607: 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

3977-529: 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

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4074-503: 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

4171-561: The Bayer designation if the latter contains an extra attached number; for example, " 55 Cancri " is more common than "Rho Cancri". There are examples of stars, such as 10 Ursae Majoris in Lynx , bearing Flamsteed designations for constellations in which they do not lie, just as there are for Bayer designations, because of the compromises that had to be made when the modern constellation boundaries were drawn up. Flamsteed's catalogue covered only

4268-742: 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

4365-504: 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

4462-533: The Latin poet Ovid . Constellations in the far southern sky were added from the 15th century until 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

4559-572: 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

4656-541: The Silver Circle", and was the heavenly abode of the Lady Arianrhod . To the ancient Balts, Corona Borealis was known as Darželis , the "flower garden". The Arabs called the constellation Alphecca (a name later given to Alpha Coronae Borealis), which means "separated" or "broken up" ( الفكة al-Fakkah ), a reference to the resemblance of the stars of Corona Borealis to a loose string of jewels. This

4753-420: The Sun and Neptune. The brighter component has been classed as a Delta Scuti variable star, though this view is not universal. The components are main sequence stars of spectral types B9V and A3V. Located 170±2 light-years away, 4.06-magnitude Delta Coronae Borealis is a yellow giant star of spectral type G3.5III that is around 2.4  M ☉ and has swollen to 7.4  R ☉ . It has

4850-441: The Sun that orbit each other every 1.14 days, orbited by a third Sun-like star every 726 years. The fourth and fifth components are a binary red dwarf system that is 14,000 AU distant from the other three stars. ADS 9731 is an even rarer multiple system in the constellation, composed of six stars, two of which are spectroscopic binaries. Corona Borealis is home to two remarkable variable stars. T Coronae Borealis

4947-647: 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

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5044-409: 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

5141-405: The asterism, adding Pi and Rho Coronae Borealis . Within the constellation's borders, there are 37 stars brighter than or equal to apparent magnitude  6.5. Alpha Coronae Borealis (officially named Alphecca by the IAU, but sometimes also known as Gemma) appears as a blue-white star of magnitude 2.2. In fact, it is an Algol -type eclipsing binary that varies by 0.1 magnitude with

5238-733: 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,

5335-655: 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

5432-474: The cluster's center is a large elliptical galaxy containing one of the most massive and most powerful supermassive black holes yet discovered. Abell 2065 is a highly concentrated galaxy cluster containing more than 400 members, the brightest of which are 16th magnitude; the cluster is more than one billion light-years from Earth. On a larger scale still, Abell 2065, along with Abell 2061 , Abell 2067 , Abell 2079 , Abell 2089 , and Abell 2092 , make up

5529-461: The constellation to be a gathering point for Men's Law, Women's Law and Law of both sexes come together and consider matters of existence. Corona Borealis was renamed Corona Firmiana in honour of the Archbishop of Salzburg in the 1730 Atlas Mercurii Philosophicii Firmamentum Firminianum Descriptionem by Corbinianus Thomas, but this was not taken up by subsequent cartographers. The constellation

5626-539: The crown at her marriage to Dionysus, he placed it in the heavens to commemorate their wedding. An alternative version has the besotted Dionysus give the crown to Ariadne, who in turn gives it to Theseus after he arrives in Crete to kill the minotaur that the Cretans have demanded tribute from Athens to feed. The hero uses the crown's light to escape the labyrinth after disposing of the creature, and Dionysus later sets it in

5723-463: The crown given by the god Dionysus to the Cretan princess Ariadne and set by her in the heavens. Other cultures likened the pattern to a circle of elders, an eagle's nest, a bear's den or a smokehole. Ptolemy also listed a southern counterpart, Corona Australis , with a similar pattern. The brightest star is the magnitude  2.2 Alpha Coronae Borealis . The yellow supergiant R Coronae Borealis

5820-717: 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

5917-686: The den of the celestial bear (Alpha, Beta, Gamma and Delta Ursae Majoris). Polynesian peoples often recognized Corona Borealis; the people of the Tuamotus named it Na Kaua-ki-tokerau and probably Te Hetu . The constellation was likely called Kaua-mea in Hawaii , Rangawhenua in New Zealand , and Te Wale-o-Awitu in the Cook Islands atoll of Pukapuka . Its name in Tonga was uncertain; it

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6014-524: 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

6111-482: The diameter of the Sun. Lying 75±0.5  light-years from Earth, Alphecca is believed to be a member of the Ursa Major Moving Group of stars that have a common motion through space. Located 112±3 light-years away, Beta Coronae Borealis or Nusakan is a spectroscopic binary system whose two components are separated by 10 AU and orbit each other every 10.5 years. The brighter component

6208-399: 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

6305-425: 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

6402-475: The entire celestial sphere. Any given point in 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

6499-507: 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

6596-621: 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

6693-584: The gods, as well as how chiefs should come together to consider matters of importance. The Shawnee people saw the stars as the Heavenly Sisters , who descended from the sky every night to dance on earth. Alphecca signifies the youngest and most comely sister, who was seized by a hunter who transformed into a field mouse to get close to her. They married though she later returned to the sky, with her heartbroken husband and son following later. The Mi'kmaq of eastern Canada saw Corona Borealis as Mskegwǒm ,

6790-408: The heavens. De astronomia , attributed to Hyginus , linked it to a crown or wreath worn by Bacchus (Dionysus) to disguise his appearance when first approaching Mount Olympus and revealing himself to the gods, having been previously hidden as yet another child of Jupiter's trysts with a mortal, in this case Semele . Its proximity to the constellations Hercules (which De astronomia reports

6887-449: 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

6984-602: 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

7081-538: 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

7178-455: 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

7275-504: The same in 2024. ADS 9731 and Sigma Coronae Borealis are multiple star systems with six and five components respectively. Five stars in the constellation host Jupiter -sized exoplanets . Abell 2065 is a highly concentrated galaxy cluster one billion light-years from the Solar System containing more than 400 members, and is itself part of the larger Corona Borealis Supercluster . Covering 179 square degrees and hence 0.433% of

7372-695: 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

7469-836: 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

7566-484: The sky, Corona Borealis ranks 73rd of the IAU designated constellations by area. Its position in the Northern Celestial Hemisphere means that the whole constellation is visible to observers north of 50°S . It is bordered by Boötes to the north and west, Serpens Caput to the south, and Hercules to the east. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922,

7663-570: 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

7760-564: 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

7857-536: 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

7954-595: 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

8051-665: The star obscures it. Direct imaging with the Hubble Space Telescope shows extensive dust clouds out to a radius of around 2000 AU from the star, corresponding with a stream of fine dust (composed of grains 5  nm in diameter) associated with the star's stellar wind and coarser dust (composed of grains with a diameter of around 0.14  μm ) ejected periodically. There are several other variables of reasonable brightness for amateur astronomer to observe, including three Mira-type long period variables: S Coronae Borealis ranges between magnitudes 5.8 and 14.1 over

8148-403: The stars visible from Great Britain , and therefore stars of the far southern constellations have no Flamsteed numbers. Some stars, such as the nearby star 82 Eridani, were named in a major southern-hemisphere catalog called Uranometria Argentina , by Benjamin Gould ; these are Gould numbers , rather than Flamsteed numbers, and should be differentiated with a G, as in 82 G. Eridani . Except for

8245-466: The works of Hesiod , Eudoxus and Aratus . The traditional 48 constellations, consisting of 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

8342-409: 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

8439-451: 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

8536-463: Was also interpreted as a broken dish. Among the Bedouins , the constellation was known as qaṣʿat al-masākīn ( قصعة المساكين ), or "the dish/bowl of the poor people". The Skidi people of Native Americans saw the stars of Corona Borealis representing a council of stars whose chief was Polaris. The constellation also symbolised the smokehole over a fireplace, which conveyed their messages to

8633-467: 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

8730-414: Was either called Ao-o-Uvea or Kau-kupenga . In Australian Aboriginal astronomy , the constellation is called womera ("the boomerang ") due to the shape of the stars. The Wailwun people of northwestern New South Wales saw Corona Borealis as mullion wollai "eagle's nest", with Altair and Vega —each called mullion —the pair of eagles accompanying it. The Wardaman people of northern Australia held

8827-399: Was featured as a main plot ingredient in the short story " Hypnos " by H. P. Lovecraft , published in 1923; it is the object of fear of one of the protagonists in the short story. Finnish band Cadacross released an album titled Corona Borealis in 2002. Constellation Four views of the constellation Orion : A constellation is an area on the celestial sphere in which

8924-498: 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

9021-529: Was first recorded in 1866; its second recorded outburst was in February 1946. T Coronae Borealis started dimming in March 2023 and it is known that before it goes nova it dims for about a year; for this reason it is expected to go nova at any time between March and September, 2024. T Coronae Borealis is a binary star with a red-hued giant primary and a white dwarf secondary, the two stars orbiting each other over

9118-404: Was noted to be a double star by later astronomers and its components designated Zeta and Zeta . John Flamsteed did likewise with Nu Coronae Borealis; classed by Bayer as a single star, it was noted to be two close stars by Flamsteed. He named them 20 and 21 Coronae Borealis in his catalogue , alongside the designations Nu and Nu respectively. Chinese astronomers deemed nine stars to make up

9215-475: Was once attributed to Theseus, among others) and Lyra (Theseus' lyre in one account), could indicate that the three constellations were invented as a group. Corona Borealis was one of the 48 constellations mentioned in the Almagest of classical astronomer Ptolemy . In Mesopotamia , Corona Borealis was associated with the goddess Nanaya . In Welsh mythology , it was called Caer Arianrhod, "the Castle of

9312-688: 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

9409-406: 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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