Pegasus is a

constellation 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 origins of the earliest constellation ...

in the northern sky, named after the winged horse

Pegasus Pegasus ( grc-gre, Πήγασος, Pḗgasos; la, Pegasus, Pegasos) is one of the best known creatures in Greek mythology. He is a winged divine stallion usually depicted as pure white in color. He was sired by Poseidon, in his role as hor ...

Greek mythology A major branch of classical mythology, Greek mythology is the body of myths originally told by the ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the origin and nature of the world, the lives and activities o ...

. It was one of the 48 constellations listed by the 2nd-century

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either ...

Ptolemy Claudius Ptolemy (; grc-gre, Πτολεμαῖος, ; la, Claudius Ptolemaeus; AD) was a mathematician, astronomer, astrologer, geographer, and music theorist, who wrote about a dozen scientific treatises, three of which were of importanc ...

, and is one of the 88 constellations recognised today. With an

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

varying between 2.37 and 2.45, the brightest star in Pegasus is the orange supergiant Epsilon Pegasi, also known as Enif, which marks the horse's muzzle.

Alpha Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , whi ...

(Markab),

Beta Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labiod ...

(Scheat), and

Gamma Gamma (uppercase , lowercase ; ''gámma'') is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter r ...

(Algenib), together with Alpha Andromedae (Alpheratz) form the large asterism known as the ''Square of Pegasus''. Twelve star systems have been found to have exoplanets.

51 Pegasi 51 Pegasi (abbreviated 51 Peg), formally named Helvetios , is a Sun-like star located from Earth in the constellation of Pegasus. It was the first main-sequence star found to have an exoplanet (designated 51 Pegasi b, officially named ...

was the first Sun-like star discovered to have an exoplanet companion.

Mythology

The Babylonian constellation IKU (field) had four stars of which three were later part of the Greek constellation ''Hippos'' (Pegasus). Pegasus, in Greek mythology, was a winged horse with magical powers. One myth regarding his powers says that his hooves dug out a spring, Hippocrene, which blessed those who drank its water with the ability to write poetry. Pegasus was born when

Perseus In Greek mythology, Perseus ( /ˈpɜːrsiəs, -sjuːs/; Greek: Περσεύς, translit. Perseús) is the legendary founder of Mycenae and of the Perseid dynasty. He was, alongside Cadmus and Bellerophon, the greatest Greek hero and slayer ...

cut off the head of

Medusa In Greek mythology, Medusa (; Ancient Greek: Μέδουσα "guardian, protectress"), also called Gorgo, was one of the three monstrous Gorgons, generally described as winged human females with living venomous snakes in place of hair. Those ...

, who was impregnated by the god

Poseidon Poseidon (; grc-gre, Ποσειδῶν) was one of the Twelve Olympians in ancient Greek religion and myth, god of the sea, storms, earthquakes and horses.Burkert 1985pp. 136–139 In pre-Olympian Bronze Age Greece, he was venerated as ...

. He was born with Chrysaor from Medusa's blood. Eventually, it became the horse for

Bellerophon Bellerophon (; Ancient Greek: Βελλεροφῶν) or Bellerophontes (), born as Hipponous, was a hero of Greek mythology. He was "the greatest hero and slayer of monsters, alongside Cadmus and Perseus, before the days of Heracles", and h ...

, who was asked to kill the Chimera and succeeded with the help of

Athena Athena or Athene, often given the epithet Pallas, is an ancient Greek goddess associated with wisdom, warfare, and handicraft who was later syncretized with the Roman goddess Minerva. Athena was regarded as the patron and protectress of v ...

and Pegasus. Despite this success, after the death of his children, Bellerophon asked Pegasus to take him to

Mount Olympus Mount Olympus (; el, Όλυμπος, Ólympos, also , ) is the highest mountain in Greece. It is part of the Olympus massif near the Thermaic Gulf of the Aegean Sea, located in the Olympus Range on the border between Thessaly and Macedonia, be ...

. Though Pegasus agreed, he plummeted back to Earth after Zeus either threw a thunderbolt at him or sent a gadfly to make Pegasus buck him off. In ancient Persia, Pegasus was depicted by

al-Sufi ʿAbd al-Rahman al-Sufi ( fa, عبدالرحمن صوفی; December 7, 903 – May 25, 986) was an iranianRobert Harry van Gent. Biography of al-Sūfī'. "The Persian astronomer Abū al-Husayn ‘Abd al-Rahmān ibn ‘Umar al-Sūfī was born in ...

as a complete horse facing east, unlike most other uranographers, who had depicted Pegasus as half of a horse, rising out of the ocean. In al-Sufi's depiction, Pegasus's head is made up of the stars of Lacerta the lizard. Its right foreleg is represented by β Peg and its left foreleg is represented by η Peg, μ Peg, and λ Peg; its hind legs are marked by 9 Peg. The back is represented by π Peg and μ Cyg, and the belly is represented by ι Peg and κ Peg. In

Chinese astronomy Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years. The ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the tw ...

, the modern constellation of Pegasus lies in The Black Tortoise of the north (北方玄武), where the stars were classified in several separate asterisms of stars. Epsilon and Theta Pegasi are joined with Alpha Aquarii to form ''Wei'' 危 "rooftop", with Theta forming the roof apex. In Hindu astronomy, the Great Square of Pegasus contained the 26th and 27th

lunar mansion Often called lunar mansion, a lunar station or lunar house is a segment of the ecliptic through which the Moon passes in its orbit around the Earth. The concept was used by several ancient cultures as part of their calendrical system. Stations ...

s. More specifically, it represented a bedstead that was a resting place for the Moon. For the

Warrau The Warao are an indigenous Amerindian people inhabiting northeastern Venezuela, Trinidad and Tobago, Guyana, and Suriname. Alternate common spellings of Warao are Waroa, Guarauno, Guarao, and Warrau. The term ''Warao'' translates as "the boat pe ...

and

Arawak The Arawak are a group of indigenous peoples of northern South America and of the Caribbean. Specifically, the term "Arawak" has been applied at various times to the Lokono of South America and the Taíno, who historically lived in the Greate ...

peoples in

Guyana Guyana ( or ), officially the Cooperative Republic of Guyana, is a country on the northern mainland of South America. Guyana is an indigenous word which means "Land of Many Waters". The capital city is Georgetown. Guyana is bordered by the ...

the stars in the Great Square, corresponding to parts of Pegasus and of Andromeda, represented a barbecue, taken up to the sky by the seven hunters of the myth of Siritjo.

Characteristics

Covering 1121 square degrees, Pegasus is the seventh-largest of the 88 constellations. Pegasus is bordered by Andromeda to the north and east, Lacerta to the north, Cygnus to the northwest,

Vulpecula Vulpecula is a faint constellation in the northern sky. Its name is Latin for "little fox", although it is commonly known simply as the fox. It was identified in the seventeenth century, and is located in the middle of the Summer Triangle (an ...

Delphinus Delphinus (Pronounced or ) is a small constellation in the Northern Celestial Hemisphere, close to the celestial equator. Its name is the Latin version for the Greek word for dolphin (). It is one of the 48 constellations listed by the 2n ...

and Equuleus to the west,

Aquarius Aquarius may refer to: Astrology * Aquarius (astrology), an astrological sign * Age of Aquarius, a time period in the cycle of astrological ages Astronomy * Aquarius (constellation) * Aquarius in Chinese astronomy Arts and entertainment ...

to the south and

Pisces Pisces may refer to: * Pisces, an obsolete (because of land vertebrates) taxonomic superclass including all fish *Pisces (astrology), an astrological sign *Pisces (constellation), a constellation ** Pisces Overdensity, an overdensity of stars in t ...

to the south and east. The three-letter abbreviation for the constellation, as adopted by the IAU in 1922, is "Peg". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined as a polygon of 35 segments. In the

equatorial coordinate system The equatorial coordinate system is a celestial coordinate system widely used to specify the positions of celestial objects. It may be implemented in spherical or rectangular coordinates, both defined by an origin at the centre of Earth, a fu ...

the

right ascension Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the March equinox to the ( hour circle of the) point in question above the earth. When pair ...

coordinates of these borders lie between and , while the

declination In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. Declination's angle is measured north or south of th ...

coordinates are between 2.33° and 36.61°. Its position in the Northern Celestial Hemisphere means that the whole constellation is visible to observers north of 53°S. Sidney Hall - Urania's Mirror - Pegasus and Equuleus (best currently available version - 2014)

Sidney Hall - Urania's Mirror - Pegasus and Equuleus (best currently available version - 2014)

Pegasus is dominated by a roughly square asterism, although one of the stars, Delta Pegasi or Sirrah, is now officially considered to be Alpha Andromedae, part of Andromeda, and is more usually called "Alpheratz". Traditionally, the body of the horse consists of a quadrilateral formed by the stars α Peg, β Peg, γ Peg, and α And. The front legs of the winged horse are formed by two crooked lines of stars, one leading from η Peg to κ Peg and the other from μ Peg to 1 Pegasi. Another crooked line of stars from α Peg via θ Peg to ε Peg forms the neck and head; ε is the snout.

Features

Stars

Bayer catalogued what he counted as 23 stars in the constellation, giving them the

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars ...

s Alpha to Psi. He saw Pi Pegasi as one star, and was uncertain of its brightness, wavering between magnitude 4 and 5. Flamsteed labelled this star 29 Pegasi, but Bode concluded that the stars 27 and 29 Pegasi should be Pi¹ and Pi² Pegasi and that Bayer had seen them as a single star. Flamsteed added lower case letters e through to y, omitting A to D as they had been used on Bayer's chart to designate neighbouring constellations and the equator. He numbered 89 stars (now with Flamsteed designations), though 6 and 11 turned out to be stars in Aquarius. Within the constellation's borders there are 177 stars of

6.5 or greater. Epsilon Pegasi, also known as Enif, marks the horse's muzzle. The brightest star in Pegasus, is an orange

supergiant Supergiants are among the most massive and most luminous stars. Supergiant stars occupy the top region of the Hertzsprung–Russell diagram with absolute visual magnitudes between about −3 and −8. The temperature range of supergiant stars spa ...

spectral type In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the ...

K21b that is around 12 times as massive as the Sun and is around 690

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distance, astronomical distances and is equivalent to about 9.46 Orders of magnitude (numbers)#1012, trillion kilometers (), or 5.88 ...

s distant from Earth. It is an irregular variable, its

varying between 2.37 and 2.45. Lying near Enif is AG Pegasi, an unusual star that brightened to magnitude 6.0 around 1885 before dimming to magnitude 9. It is composed of a

red giant A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around o ...

and

white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes ...

, estimated to be around 2.5 and 0.6 times the mass of the Sun respectively. With its outburst taking over 150 years, it has been described as the slowest

nova A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramat ...

ever recorded. Three stars with Bayer designations that lie within the Great Square are variable stars. Phi and Psi Pegasi are pulsating red giants, while Tau Pegasi (the proper name is Salm), is a Delta Scuti variable—a class of short period (six hours at most) pulsating stars that have been used as

standard candles The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A ''direct'' distance measurement of an astronomical object is possible o ...

and as subjects to study astroseismology. Rotating rapidly with a

projected rotational velocity Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bulge ...

of 150 km s⁻¹, Kerb is almost 30 times as luminous as the Sun and has a pulsation period of 56.5 minutes. With an outer atmosphere at an

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

of 7,762 K, it is a white star with a spectral type of A5IV.

Zeta Zeta (, ; uppercase Ζ, lowercase ζ; grc, ζῆτα, el, ζήτα, label= Demotic Greek, classical or ''zē̂ta''; ''zíta'') is the sixth letter of the Greek alphabet. In the system of Greek numerals, it has a value of 7. It was derived f ...

, Xi,

Rho Rho (uppercase Ρ, lowercase ρ or ; el, ρο or el, ρω, label=none) is the 17th letter of the Greek alphabet. In the system of Greek numerals it has a value of 100. It is derived from Phoenician letter res . Its uppercase form uses the sa ...

and Sigma Pegasi mark the horse's neck. The brightest of these with a magnitude of 3.4 is Zeta, also traditionally known as Homam. Lying seven degrees southwest of Markab, it is a blue-white main sequence star of spectral type B8V located around 209 light-years distant. It is a

slowly pulsating B star A slowly pulsating B-type star (SPB), formerly known as a 53 Persei variable, is a type of pulsating variable star. They may also be termed a long-period pulsating B star (LPB). As the name implies, they are main-sequence stars of spectral type B2 ...

that varies slightly in luminosity with a period of 22.952 ± 0.804 hours, completing 1.04566 cycles per day. Xi lies 2 degrees northeast, and is a yellow-white main sequence star of spectral type F6V that is 86% larger and 17% more massive that the Sun, and radiate 4.5 times the

solar luminosity The solar luminosity (), is a unit of radiant flux ( power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun. One nominal ...

. It has a red dwarf companion that is 192.3 au distant. If (as is likely) the smaller star is in orbit around the larger star, then it would take around 2000 years to complete a revolution.

Theta Pegasi θ Pegasi, Latinized as Theta Pegasi, is a single star in the equatorial constellation of Pegasus, lying about 7.5 degrees southwest of Enif. It has the traditional name Biham , and the Flamsteed designation 26 Pegasi. This object is ...

marks the horse's eye. Also known as Biham, it is a 3.43-magnitude white main sequence star of spectral type A2V, around 1.8 times as massive, 24 times as luminous, and 2.3 times as wide as the Sun. See Table 3.

(Markab),

(Scheat), and

(Algenib), together with Alpha Andromedae (Alpheratz or Sirrah) form the large asterism known as the ''Square of Pegasus''. The brightest of these, Alpheratz was also known as both Delta Pegasi and Alpha Andromedae before being placed in Andromeda in 1922 with the setting of constellation boundaries. The second brightest star is Scheat, a

of spectral type M2.5II-IIIe located around 196 light-years away from Earth. It has expanded until it is some 95 times as large, and has a total

luminosity Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a st ...

1,500 times that of the Sun. Beta Pegasi is a semi-regular variable that varies from magnitude 2.31 to 2.74 over a period of 43.3 days. Markab and Algenib are blue-white stars of spectral types B9III and B2IV located 133 and 391 light-years distant respectively. Appearing to have moved off the main sequence as their core hydrogen supply is being or has been exhausted, they are enlarging and cooling to eventually become red giant stars. Markab has an apparent magnitude of 2.48, while Algenib is a

Beta Cephei variable Beta Cephei variables, also known as Beta Canis Majoris stars, are variable stars that exhibit small rapid variations in their brightness due to pulsations of the stars' surfaces, thought due to the unusual properties of iron at temperatures of 200 ...

that varies between magnitudes 2.82 and 2.86 every 3 hours 38 minutes, and also exhibits some slow pulsations every 1.47 days.

Eta Eta (uppercase , lowercase ; grc, ἦτα ''ē̂ta'' or ell, ήτα ''ita'' ) is the seventh letter of the Greek alphabet, representing the close front unrounded vowel . Originally denoting the voiceless glottal fricative in most dialects, ...

and

Omicron Pegasi ο Pegasi, Latinized as Omicron Pegasi, is a suspected astrometric binary star system in the northern constellation of Pegasus. It is white in hue and visible to the naked eye as a faint point of light with an apparent visual magnitude o ...

mark the left knee and Pi Pegasi the left hoof, while

Iota Iota (; uppercase: Ι, lowercase: ι; ) is the ninth letter of the Greek alphabet. It was derived from the Phoenician letter Yodh. Letters that arose from this letter include the Latin I and J, the Cyrillic І (І, і), Yi (Ї, ї), and ...

and Kappa Pegasi mark the right knee and hoof. Also known as Matar, Eta Pegasi is the fifth-brightest star in the constellation. Shining with an apparent magnitude of 2.94, it is a multiple star system composed of a yellow giant of spectral type G2 and a yellow-white main sequence star of spectral type A5V that are 3.2 and 2.0 times as massive as our Sun. The two revolve around each other every 2.24 years. Farther afield is a binary system of two G-type main sequence stars, that would take 170,000 years to orbit the main pair if they are in fact related. Omicron Pegasi has a magnitude of 4.79. Located 300 ± 20 light-years distant from Earth, it is a white subgiant that has begun to cool, expand and brighten as it exhausts its core hydrogen fuel and moves off the main sequence. Pi¹ and Pi² Pegasi appear as an optical double to the unaided eye as they are separated by 10 arcminutes, and are not a true binary system. Located 289 ± 8 light-years distant, Pi¹ is an ageing yellow giant of spectral type G6III, 1.92 times as massive and around 200 times as luminous as the Sun. Pi² is a yellow-white subgiant that is 2.5 times as massive as the Sun and has expanded to 8 times the Sun's radius and brightened to 92 times the Sun's luminosity. It is surrounded by a circumstellar disk spinning at 145 km a second, and is 263 ± 4 light-years distant from Earth. IK Pegasi is a close binary comprising an

A-type main-sequence star An A-type main-sequence star (A V) or A dwarf star is a main-sequence ( hydrogen-burning) star of spectral type A and luminosity class V (five). These stars have spectra defined by strong hydrogen Balmer absorption lines. They measure betwe ...

and

in very close orbit; the latter a candidate for a future

type Ia supernova A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...

as its main star runs out of core hydrogen fuel and expands into a giant and transfers material to the smaller star. Twelve star systems have been found to have

exoplanet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

was the first Sun-like star discovered to have an exoplanet companion;

51 Pegasi b 51 Pegasi b, officially named Dimidium , and formerly unofficially dubbed Bellerophon , is an extrasolar planet approximately away in the constellation of Pegasus. It was the first exoplanet to be discovered orbiting a main-sequence star, the ...

(unofficially named Bellerophon, officially named Dimidium) is a

hot Jupiter Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (). The close proximity to their stars and high surface-atmosphere t ...

close to its sun, completing an orbit every four days. Spectroscopic analysis of HD 209458 b, an

extrasolar planet An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, init ...

in this constellation, has provided the first evidence of atmospheric

water vapor (99.9839 °C) , - , Boiling point , , - , specific gas constant , 461.5 J/( kg·K) , - , Heat of vaporization , 2.27 MJ/kg , - , Heat capacity , 1.864 kJ/(kg·K) Water vapor, water vapour or aqueous vapor is the gaseous p ...

beyond the solar system, while extrasolar planets orbiting the star HR 8799 also in Pegasus are the first to be directly imaged. V391 Pegasi is a hot subdwarf star that has been found to have a planetary companion. Auv0164 pegasus

Named stars

Deep-sky objects

Stephan's Quintet taken by James Webb Space Telescope

M15 (NGC 7078) is a

globular cluster A globular cluster is a spheroidal conglomeration of stars. Globular clusters are bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many millions of membe ...

of magnitude 6.4, 34,000 light-years from Earth. It is a Shapley class IV cluster, which means that it is fairly rich and concentrated towards its center. M15 was discovered in 1746 by Jean-Dominique Maraldi. Pease 1 is a

planetary nebula A planetary nebula (PN, plural PNe) is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is a misnomer because they are unrelate ...

located within the

and was the first planetary nebula known to exist within a globular cluster. It has an apparent magnitude of 15.5.

NGC 7331 NGC 7331, also known as Caldwell 30, is an unbarred spiral galaxy about away in the constellation Pegasus. It was discovered by William Herschel in 1784. NGC 7331 is the brightest galaxy in the field of a visual grouping known as the NGC 733 ...

is a

spiral galaxy Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work ''The Realm of the Nebulae''William Herschel Frederick William Herschel (; german: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline ...

in 1784 and was later one of the first nebulous objects to be described as "spiral" by William Parsons. Another of Pegasus's galaxies is NGC 7742, a Type 2

Seyfert galaxy Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectr ...

. Located at a distance of 77 million light-years with a redshift of 0.00555, it is an active galaxy with a

supermassive black hole A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical ob ...

at its core. Its characteristic emission lines are produced by gas moving at high speeds around the central black hole. Pegasus is also noted for its more unusual galaxies and exotic objects. Einstein's Cross is a

quasar A quasar is an extremely luminous active galactic nucleus (AGN). It is pronounced , and sometimes known as a quasi-stellar object, abbreviated QSO. This emission from a galaxy nucleus is powered by a supermassive black hole with a mass rangi ...

that has been lensed by a foreground galaxy. The

elliptical galaxy An elliptical galaxy is a type of galaxy with an approximately ellipsoidal shape and a smooth, nearly featureless image. They are one of the four main classes of galaxy described by Edwin Hubble in his Hubble sequence and 1936 work ''The Real ...

is 400 million light-years away with a

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in fr ...

of 0.0394, but the quasar is 8 billion light-years away. The lensed quasar resembles a cross because the gravitational force of the foreground galaxy on its light creates four images of the quasar.

Stephan's Quintet Stephan's Quintet is a visual grouping of five galaxies of which four form the first compact galaxy group ever discovered. The group, visible in the constellation Pegasus, was discovered by Édouard Stephan in 1877 at the Marseille Observatory. ...

is another unique object located in Pegasus. It is a cluster of five galaxies at a distance of 300 million light-years and a redshift of 0.0215. First discovered by

Édouard Stephan Édouard Jean-Marie Stephan (31 August 1837 – 31 December 1923) was a French astronomer. His surname is sometimes spelled Stéphan in some literature, but this is apparently erroneous. He was born in Sainte Pezenne (today one of the districts ...

, a Frenchman, in 1877, the Quintet is unique for its interacting galaxies. Two of the galaxies in the middle of the group have clearly begun to collide, sparking massive bursts of star formation and drawing off long "tails" of stars. Astronomers have predicted that all five galaxies may eventually merge into one large elliptical galaxy.

Namesakes

USS ''Pegasus'' (AK-48) and USS ''Pegasus'' (PHM-1) are United States navy ships named after the constellation "Pegasus". The

Beyblade is a line of spinning-top toys originally developed by Takara, first released in Japan in July 1999, along with its debut series. Following Takara's merger with Tomy in 2006, Beyblades are now developed by Takara Tomy. Various toy companies ...

top Storm Pegasus 105RF and its evolutions Galaxy Pegasus W105R2F and Cosmic Pegasus F:D are based on Pegasus constellation. Pegasus Seiya from the anime of

Saint Seiya , also known as ''Saint Seiya: Knights of the Zodiac'' or simply ''Knights of the Zodiac'' (translated from the French title ''Les Chevaliers du Zodiaque''), is a Japanese manga series written and illustrated by Masami Kurumada. It w ...

was named after the constellation Pegasus.

Notes

References

Cited texts

* * *

External links

The Deep Photographic Guide to the Constellations: Pegasus

Warburg Institute Iconographic Database (medieval and early modern images of Pegasus)
{{DEFAULTSORT:Pegasus (Constellation) Constellations Northern constellations Constellations listed by Ptolemy Pegasus