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An asterism is an observed pattern or group of
star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...
s in the
sky The sky is an unobstructed view upward from the planetary surface, surface of the Earth. It includes the atmosphere of Earth, atmosphere and outer space. It may also be considered a place between the ground and outer space, thus distinct from ...
. Asterisms can be any identified star pattern, and therefore are a more general concept than the 88 formally defined
constellations 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 defin ...
. Constellations are based upon asterisms, but unlike asterisms, constellations are defined regions with official boundaries which together encompass the entire sky. Asterisms range from simple shapes of just a few stars to more complex collections of many stars covering large portions of the sky. The stars themselves may be bright naked-eye objects or fainter, even telescopic, but they are generally all of a similar brightness to each other. The larger brighter asterisms are useful for people who are familiarizing themselves with the night sky. The patterns of stars seen in asterisms are not necessarily a product of any physical association between the stars, but are rather the result of the particular perspectives of their observations. For example the
Summer Triangle The Summer Triangle is an astronomical asterism in the northern celestial hemisphere. The defining vertices of this imaginary triangle are at Altair, Deneb, and Vega, each of which is the brightest star of its constellation ( Aquila, Cygn ...
is a purely observational, physically unrelated group of stars, but the stars of
Orion's Belt Orion's Belt is an asterism in the constellation of Orion. Other names include the Belt of Orion, the Three Kings, and the Three Sisters. The belt consists of three bright and easily identifiable collinear star systems – Alnitak, Alnilam, ...
are all members of the Orion OB1 association and five of the seven stars of the Big Dipper are members of the
Ursa Major Moving Group The Ursa Major Moving Group, also known as Collinder 285 and the Ursa Major association, is the closest Stellar kinematics#Moving groups, stellar moving group – a set of stars with common velocities in space and thought to have a common orig ...
. Physical associations, such as the
Hyades Hyades may refer to: *Hyades (band) *Hyades (mythology) *Hyades (star cluster), an open star cluster in the constellation Taurus {{Disambiguation it:Iadi ...
or
Pleiades The Pleiades (), also known as Seven Sisters and Messier 45 (M45), is an Asterism (astronomy), asterism of an open cluster, open star cluster containing young Stellar classification#Class B, B-type stars in the northwest of the constellation Tau ...
, can be asterisms in their own right and also part of other asterisms.


Background of asterisms and constellations

In many early civilizations, it was common to associate groups of stars in
connect-the-dots Connect the dots (also known as connect-the-dots, dot to dot, join the dots or follow the dots) is a form of puzzle containing a sequence of numbered dots. When a line is drawn connecting the dots the outline of an object is revealed. The puzz ...
stick-figure patterns. Some of the earliest records are those of ancient India in the
Vedanga Jyotisha ''Vedanga Jyotisha'' (), or ''Jyotishavedanga'' (), is one of earliest known Indian texts on astrology ('' Jyotisha''). The extant text is dated to the final centuries BCE, but it may be based on a tradition reaching back to about 700-600 BCE. ...
and the
Babylonians Babylonia (; , ) was an ancient Akkadian-speaking state and cultural area based in the city of Babylon in central-southern Mesopotamia (present-day Iraq and parts of Kuwait, Syria and Iran). It emerged as an Akkadian-populated but Amorite-ru ...
. Different cultures identified different constellations, although a few of the more obvious patterns tend to appear in the constellations of multiple cultures, such as those of Orion and
Scorpius Scorpius is a zodiac constellation located in the Southern celestial hemisphere, where it sits near the center of the Milky Way, between Libra to the west and Sagittarius to the east. Scorpius is an ancient constellation whose recognition pred ...
. As anyone could arrange and name a grouping of stars there was no distinct difference between a ''constellation'' and an ''asterism''. For example,
Pliny the Elder Gaius Plinius Secundus (AD 23/24 79), known in English as Pliny the Elder ( ), was a Roman Empire, Roman author, Natural history, naturalist, and naval and army commander of the early Roman Empire, and a friend of the Roman emperor, emperor Vesp ...
mentions 72 asterisms in his book
Naturalis Historia The ''Natural History'' () is a Latin work by Pliny the Elder. The largest single work to have survived from the Roman Empire to the modern day, the ''Natural History'' compiles information gleaned from other ancient authors. Despite the work' ...
. A general list containing 48 constellations likely began to develop with the astronomer
Hipparchus Hipparchus (; , ;  BC) was a Ancient Greek astronomy, Greek astronomer, geographer, and mathematician. He is considered the founder of trigonometry, but is most famous for his incidental discovery of the precession of the equinoxes. Hippar ...
(c. 190 – c. 120 BCE). As constellations were considered to be composed only of the stars that constituted the figure, it was always possible to use any leftover stars to create and squeeze in a new grouping among the established constellations. Exploration by Europeans to other parts of the globe exposed them to stars previously unknown to them. Two astronomers particularly known for greatly expanding the number of southern constellations were
Johann Bayer Johann Bayer (; 1572 – 7 March 1625) was a German lawyer and uranographer (celestial cartographer). He was born in Rain in 1572. In 1592, aged 20, he began his study of philosophy and law at the University of Ingolstadt, after which he ...
(1572–1625) and
Nicolas Louis de Lacaille Abbé Nicolas-Louis de Lacaille (; 15 March 171321 March 1762), formerly sometimes spelled de la Caille, was a French astronomer and geodesist who named 14 out of the 88 constellations. From 1750 to 1754, he studied the sky at the Cape of Goo ...
(1713–1762). Bayer had listed twelve figures made out of stars that were too far south for
Ptolemy Claudius Ptolemy (; , ; ; – 160s/170s AD) was a Greco-Roman mathematician, astronomer, astrologer, geographer, and music theorist who wrote about a dozen scientific treatises, three of which were important to later Byzantine science, Byzant ...
to have seen. Lacaille created 14 new groups, mostly for the area surrounding
South Celestial Pole The north and south celestial poles are the two points in the sky where Earth's axis of rotation, indefinitely extended, intersects the celestial sphere. The north and south celestial poles appear permanently directly overhead to observers at ...
. Many of these proposed constellations have been formally accepted, but the rest have remained as asterisms. In 1928, the
International Astronomical Union The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...
(IAU) precisely divided the sky into 88 official constellations following geometric boundaries encompassing all of the stars within them. Any additional new selected groupings of stars or
former constellation Former constellations are old historical Western constellations that for various reasons are no longer widely recognised or are not officially recognised by the International Astronomical Union (IAU). Prior to 1930, many of these defunct const ...
s are often considered as asterisms. However, technical distinctions between the terms 'constellation' and 'asterism' often remain somewhat ambiguous.


Asterisms consisting of first-magnitude stars

Some asterisms consist completely of bright
first-magnitude star First-magnitude stars are the brightest stars in the night sky, with apparent magnitudes lower (i.e. brighter) than +1.50. Hipparchus, in the 1st century BC, introduced the magnitude scale. He allocated the first magnitude to the 20 brightest star ...
s, which mark out simple geometric shapes. * The ''
Summer Triangle The Summer Triangle is an astronomical asterism in the northern celestial hemisphere. The defining vertices of this imaginary triangle are at Altair, Deneb, and Vega, each of which is the brightest star of its constellation ( Aquila, Cygn ...
'' of
Deneb Deneb () is a blue supergiant star in the constellation of Cygnus. It is the brightest star in the constellation and the 19th brightest in the night sky, with an apparent magnitude slightly varying between +1.21 and +1.29. Deneb is one ...
,
Altair Altair is the brightest star in the constellation of Aquila (constellation), Aquila and the list of brightest stars, twelfth-brightest star in the night sky. It has the Bayer designation Alpha Aquilae, which is Latinisation of name ...
, and
Vega Vega is the brightest star in the northern constellation of Lyra. It has the Bayer designation α Lyrae, which is Latinised to Alpha Lyrae and abbreviated Alpha Lyr or α Lyr. This star is relatively close at only from the Sun, and ...
– α Cygni, α Aquilae, and α
Lyra , from ; pronounced: ) is a small constellation. It is one of the 48 listed by the 2nd century astronomer Ptolemy, and is one of the modern 88 constellations recognized by the International Astronomical Union. Lyra was often represented on star ...
e – is prominent in the northern hemisphere summer skies, as its three stars are all of the 1st magnitude. The stars of the Triangle are in the band of the
Milky Way The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galax ...
which marks the galactic equator, and are in the direction of the
Galactic Center The Galactic Center is the barycenter of the Milky Way and a corresponding point on the rotational axis of the galaxy. Its central massive object is a supermassive black hole of about 4 million solar masses, which is called Sagittarius A*, a ...
. * The '' Winter Triangle'' is visible in the northern sky's winter and comprises the first magnitude stars
Betelgeuse Betelgeuse is a red supergiant star in the constellation of Orion (constellation), Orion. It is usually the List of brightest stars, tenth-brightest star in the night sky and, after Rigel, the second brightest in its constellation. It i ...
,
Sirius Sirius is the brightest star in the night sky. Its name is derived from the Greek word (Latin script: ), meaning 'glowing' or 'scorching'. The star is designated  Canis Majoris, Latinized to Alpha Canis Majoris, and abbr ...
and
Procyon Procyon () is the brightest star in the constellation of Canis Minor and usually the list of brightest stars, eighth-brightest star in the night sky, with an apparent visual magnitude of 0.34. It has the Bayer designation α Canis Min ...
(the second and fourth closest star or star system visible without aid). ** The larger northern ''
Winter Hexagon The Winter Hexagon is an asterism appearing to be in the form of a hexagon with vertices at Rigel, Aldebaran, Capella, Pollux, Procyon, and Sirius. It is mostly upon the Northern Hemisphere's celestial sphere. On most locations on Earth (exc ...
'' includes seven of the twenty-two first-magnitude stars visible in the sky, with Pollux,
Capella Capella is the brightest star in the northern constellation of Auriga. It has the Bayer designation α Aurigae, which is Latinisation of names, Latinised to Alpha Aurigae and abbreviated Alpha Aur or α Aur. Capella is the lis ...
,
Aldebaran Aldebaran () is a star in the zodiac constellation of Taurus. It has the Bayer designation α Tauri, which is Latinized to Alpha Tauri and abbreviated Alpha Tau or α Tau. Aldebaran varies in brightness from an apparent vis ...
,
Rigel Rigel is a blue supergiant star in the constellation of Orion. It has the Bayer designation β Orionis, which is Latinized to Beta Orionis and abbreviated Beta Ori or β Ori. Rigel is the brightest and most massive componentand ...
, Sirius and Procyon, and with the 2nd-magnitude Castor on the periphery, and Betelgeuse off-center. Adding
Betelgeuse Betelgeuse is a red supergiant star in the constellation of Orion (constellation), Orion. It is usually the List of brightest stars, tenth-brightest star in the night sky and, after Rigel, the second brightest in its constellation. It i ...
then it is known as the ''Heavenly 'G. It encircles the galactic anticenter, as well as incorporates constellations such as
Gemini Gemini most often refers to: * Gemini (constellation), one of the constellations of the zodiac * Gemini (astrology), an astrological sign Gemini may also refer to: Science and technology Space * Gemini in Chinese astronomy, the Gemini constellat ...
and Orion. It also includes in the background of Aldebaran the
Hyades Hyades may refer to: *Hyades (band) *Hyades (mythology) *Hyades (star cluster), an open star cluster in the constellation Taurus {{Disambiguation it:Iadi ...
, the nearest
star cluster A star cluster is a group of stars held together by self-gravitation. Two main types of star clusters can be distinguished: globular clusters, tight groups of ten thousand to millions of old stars which are gravitationally bound; and open cluster ...
and one of five first-magnitude
deep-sky object A deep-sky object (DSO) is any astronomical object that is not an individual star or Solar System object (such as Sun, Moon, planet, comet, etc.). The classification is used for the most part by amateur astronomers to denote visually observed fa ...
s, two of which can be seen just north-east of the Hyades, the
Pleiades The Pleiades (), also known as Seven Sisters and Messier 45 (M45), is an Asterism (astronomy), asterism of an open cluster, open star cluster containing young Stellar classification#Class B, B-type stars in the northwest of the constellation Tau ...
also in the Taurus constellation and the
Alpha Persei Cluster The Alpha Persei Cluster, also known as Melotte 20 or Collinder 39, is an open cluster of stars in the northern constellation of Perseus (constellation), Perseus. To the naked eye, the cluster consists of several blue-hued spectral type B stars. ...
(with
Alcyone In Greek mythology, Alcyone (or dubiously Halcyone) (; ) and Ceyx (; ) were a wife and husband who incurred the wrath of the god Zeus for their romantic hubris. Etymology Alkyóne comes from alkyón (), which refers to a sea-bird with a mour ...
and Mirfak as the brightest stars). * The northern ''
Spring Triangle The Spring Triangle is an asterism_(astronomy), astronomical asterism involving an imaginary triangle drawn upon the celestial sphere, with its defining vertices at Arcturus, Spica, and Regulus. This triangle connects the constellations of Boötes ...
'' consists of
Arcturus , - bgcolor="#FFFAFA" , Note (category: variability): , , H and K emission vary. Arcturus is a red giant star in the Northern celestial hemisphere, northern constellation of Boötes, and the brightest star in the constellation. It ha ...
,
Regulus Regulus is the brightest object in the constellation Leo (constellation), Leo and one of the List of brightest stars, brightest stars in the night sky. It has the Bayer designation designated α Leonis, which is Latinisation of names, ...
and
Spica Spica is the brightest object in the constellation of Virgo and one of the 20 brightest stars in the night sky. It has the Bayer designation α Virginis, which is Latinised to Alpha Virginis and abbreviated Alpha Vir or α Vir. Analys ...
. ** The '' Great Diamond'' consisting of Arcturus, Spica, Denebola and
Cor Caroli Cor Caroli is a binary star in the northern constellation of Canes Venatici. It is the brightest star in the constellation, lying at the third magnitude. The International Astronomical Union uses the name "Cor Caroli" specifically for th ...
, the latter two not being first-magnitude stars.AstronomyOnline: Image of ''Big Dipper'', ''Diamond of Virgo'', ''The Sail'', ''Sickle'', and ''Asses'' and the ''Manger''
Astronomyonline.org
An east-west line from Arcturus to Denebola forms an equilateral triangle with Cor Caroli to the North, and another with Spica to the South. Together these two triangles form the Diamond. Formally, the stars of the Diamond are in the constellations
Boötes Boötes ( ) is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from , which comes from 'herder, herdsman' or 'plowman' (literally, 'o ...
,
Virgo Virgo may refer to: Arts and entertainment * Virgo (film), a 1970 Egyptian film * Virgo (character), several Marvel Comics characters * Virgo Asmita, a character in the manga ''Saint Seiya: The Lost Canvas'' * ''Virgo'' (album), by Virgo Four, ...
, Leo, and
Canes Venatici Canes Venatici ( ) is one of the 88 constellations designated by the International Astronomical Union (IAU). It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for 'hunting dogs', and ...
. Other asterisms consist partially of multiple first-magnitude stars. *The ''
Southern Cross CRUX is a lightweight x86-64 Linux distribution targeted at experienced Linux users and delivered by a tar.gz-based package system with BSD-style initscripts. It is not based on any other Linux distribution. It also utilizes a ports system to ...
'' including the first-magnitude stars Acrux and
Mimosa ''Mimosa'' is a genus of about 600 species of herbs and shrubs, in the mimosoid clade of the legume family Fabaceae. Species are native to the Americas, from North Dakota to northern Argentina, and to eastern Africa (Tanzania, Mozambique, and ...
, west of the
Carina Nebula The Carina Nebula or Eta Carinae Nebula (catalogued as NGC 3372; also known as the Great Carina Nebula) is a large, complex area of bright and dark nebulosity in the constellation Carina, located in the Carina–Sagittarius Arm of the Milky W ...
(one of five first-magnitude deep-sky objects), and with the first-magnitude stars
Alpha Centauri Alpha Centauri (, α Cen, or Alpha Cen) is a star system in the southern constellation of Centaurus (constellation), Centaurus. It consists of three stars: Rigil Kentaurus (), Toliman (), and Proxima Centauri (). Proxima Centauri ...
(the closest star to the Sun) and
Beta Centauri Beta Centauri is a triple star system in the southern constellation of Centaurus. It is officially called Hadar (). The Bayer designation of Beta Centauri is Latinised from β Centauri, and abbreviated Beta Cen or β Cen. The syst ...
pointing at the cross, distinguishing the cross from less bright and similar asterisms like the Diamond Cross or False Cross. All other first-magnitude stars are the only such stars in their asterisms or constellations, with
Canopus Canopus is the brightest star in the southern constellation of Carina (constellation), Carina and the list of brightest stars, second-brightest star in the night sky. It is also Bayer designation, designated α Carinae, which is Rom ...
in the
Argo Navis Argo Navis (the Ship Argo), or simply Argo, is one of Ptolemy's 48 constellations, now a grouping of three IAU constellations. It is formerly a single large constellation in the southern sky. The genitive is "Argus Navis", abbreviated "Arg". ...
asterism south of Sirius, visually east of the Carina Nebula and near the
Large Magellanic Cloud The Large Magellanic Cloud (LMC) is a dwarf galaxy and satellite galaxy of the Milky Way. At a distance of around , the LMC is the second- or third-closest galaxy to the Milky Way, after the Sagittarius Dwarf Spheroidal Galaxy, Sagittarius Dwarf ...
(both being first-magnitude deep-sky objects),
Achernar Achernar is the brightest star in the constellation of Eridanus and the ninth-brightest in the night sky. It has the Bayer designation Alpha Eridani, which is Latinized from α Eridani and abbreviated Alpha Eri or α Eri. The name Ac ...
in the Eridanus constellation east of Canopus, Fomalhaut in the Southern Fish constellation east of Achernar and
Antares Antares is the brightest star in the constellation of Scorpius. It has the Bayer designation α Scorpii, which is Latinisation of names, Latinised to Alpha Scorpii. Often referred to as "the heart of the scorpion", Antares is flanked by ...
in the
Scorpius Scorpius is a zodiac constellation located in the Southern celestial hemisphere, where it sits near the center of the Milky Way, between Libra to the west and Sagittarius to the east. Scorpius is an ancient constellation whose recognition pred ...
constellation visually near the
Galactic Center The Galactic Center is the barycenter of the Milky Way and a corresponding point on the rotational axis of the galaxy. Its central massive object is a supermassive black hole of about 4 million solar masses, which is called Sagittarius A*, a ...
.


Constellation-based asterisms

* The ''
Big Dipper The Big Dipper (American English, US, Canadian English, Canada) or the Plough (British English, UK, Hiberno-English, Ireland) is an asterism (astronomy), asterism consisting of seven bright stars of the constellation Ursa Major; six of them ar ...
'', also known as ''The Plough'' or ''Charles's Wain'', is composed of the seven brightest stars in
Ursa Major Ursa Major, also known as the Great Bear, is a constellation in the Northern Sky, whose associated mythology likely dates back into prehistory. Its Latin name means "greater (or larger) bear", referring to and contrasting it with nearby Ursa M ...
. These stars delineate the Bear's hindquarters and exaggerated tail, or alternatively, the "handle" forming the upper outline of the bear's head and neck. With its longer tail,
Ursa Minor Ursa Minor (, contrasting with Ursa Major), also known as the Little Bear, is a constellation located in the far northern celestial hemisphere, northern sky. As with the Great Bear, the tail of the Little Bear may also be seen as the handle of ...
hardly appears bearlike at all, and is widely known by its pseudonym, the ''Little Dipper''. * The ''Northern Cross'' in Cygnus. The upright runs from
Deneb Deneb () is a blue supergiant star in the constellation of Cygnus. It is the brightest star in the constellation and the 19th brightest in the night sky, with an apparent magnitude slightly varying between +1.21 and +1.29. Deneb is one ...
(α Cyg) in the Swan's tail to Albireo (β Cyg) in the beak. The transverse runs from ε Cygni in one wing to δ Cygni in the other. * The ''Southern Cross'' is an asterism by name, but the whole area is now recognised as the constellation
Crux CRUX is a lightweight x86-64 Linux distribution targeted at experienced Linux users and delivered by a tar.gz-based package system with BSD-style initscripts. It is not based on any other Linux distribution. It also utilizes a ports system ...
. The main stars are
Alpha Alpha (uppercase , lowercase ) 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'' , whose name comes from the West Semitic word for ' ...
,
Beta Beta (, ; uppercase , lowercase , or cursive ; or ) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Ancient Greek, beta represented the voiced bilabial plosive . In Modern Greek, it represe ...
,
Gamma Gamma (; uppercase , lowercase ; ) 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 normally repr ...
,
Delta Delta commonly refers to: * Delta (letter) (Δ or δ), the fourth letter of the Greek alphabet * D (NATO phonetic alphabet: "Delta"), the fourth letter in the Latin alphabet * River delta, at a river mouth * Delta Air Lines, a major US carrier ...
, and arguably also Epsilon Crucis. Earlier, Crux ''was'' deemed an asterism when Bayer created it in ''
Uranometria is a star atlas produced by Johann Bayer. It was published in Augsburg in 1603 by Christoph Mang (''Christophorus Mangus'') under the full title (from Latin: ''Uranometria, containing charts of all the constellations, drawn by a new method an ...
'' (1603) from the stars in the hind legs of
Centaurus Centaurus () is a bright constellation in the southern sky. One of the 88 modern constellations by area, largest constellations, Centaurus was included among the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one ...
, decreasing the size of Centaur. These same stars were probably identified by
Pliny the Elder Gaius Plinius Secundus (AD 23/24 79), known in English as Pliny the Elder ( ), was a Roman Empire, Roman author, Natural history, naturalist, and naval and army commander of the early Roman Empire, and a friend of the Roman emperor, emperor Vesp ...
in his
Naturalis Historia The ''Natural History'' () is a Latin work by Pliny the Elder. The largest single work to have survived from the Roman Empire to the modern day, the ''Natural History'' compiles information gleaned from other ancient authors. Despite the work' ...
as the asterism 'Thronos Caesaris.' * The ''Fish Hook'' is the traditional Hawaiian name for
Scorpius Scorpius is a zodiac constellation located in the Southern celestial hemisphere, where it sits near the center of the Milky Way, between Libra to the west and Sagittarius to the east. Scorpius is an ancient constellation whose recognition pred ...
. The image will be even more obvious if the chart's lines from
Antares Antares is the brightest star in the constellation of Scorpius. It has the Bayer designation α Scorpii, which is Latinisation of names, Latinised to Alpha Scorpii. Often referred to as "the heart of the scorpion", Antares is flanked by ...
(α Sco) to
Beta Scorpii Beta Scorpii is a Star system, multiple star system in the southern zodiac constellation of Scorpius. It bore the traditional proper name of Acrab , though the International Astronomical Union now regards that name as applying only to t ...
(β Sco) and
Pi Scorpii Pi Scorpii or π Scorpii, is a triple star system in the southern constellation of Scorpius. With a combined apparent magnitude of 2.9, it can be easily seen with the naked eye. Parallax measurements yield an estimated distance of aroun ...
(π Sco) are replaced with a line from Beta through
Delta Scorpii Delta Scorpii (Latinisation of names, Latinised from δ Scorpii, abbreviated Delta Sco, δ Sco) is a binary star (the presence of a third star in the system is being debated) in the constellation of Scorpius. The primary star is named Ds ...
(δ Sco) to Pi forming a large capped "J." Adding vertical lines to connect the limbs at the left and right in the main diagram of
Hercules Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures. The Romans adapted the Gr ...
will complete the figure of the Butterfly. *
Boötes Boötes ( ) is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from , which comes from 'herder, herdsman' or 'plowman' (literally, 'o ...
is sometimes known as the ''Ice Cream Cone''. It is also known as the ''Kite''. * The stars of
Cassiopeia Cassiopeia or Cassiopea may refer to: Greek mythology * Cassiopeia (mother of Andromeda), queen of Aethiopia and mother of Andromeda * Cassiopeia (wife of Phoenix), wife of Phoenix, king of Phoenicia * Cassiopeia, wife of Epaphus, king of Egy ...
form a W which is often used as a nickname. * The ''Great Square'' of
Pegasus Pegasus (; ) is a winged horse in Greek mythology, usually depicted as a white stallion. He was sired by Poseidon, in his role as horse-god, and foaled by the Gorgon Medusa. Pegasus was the brother of Chrysaor, both born from Medusa's blood w ...
is the quadrilateral formed by the stars Markab, Scheat, Algenib, and
Alpheratz Alpheratz is a prominent star system in the constellation of Andromeda. Pronounced , it has the Bayer designation Alpha Andromedae, Latinised from α Andromedae, and abbreviated Alpha And or α And, respectively. Alpheratz is the ...
, representing the body of the winged horse.AstronomyOnline: Image of ''Cassiopeia'', ''Square of Pegasus'', ''The Circlet'', and ''Y of Aquarius''
Astronomyonline.org
The asterism was recognized as the constellation ASH.IKU "The Field" on the MUL.APIN
cuneiform Cuneiform is a Logogram, logo-Syllabary, syllabic writing system that was used to write several languages of the Ancient Near East. The script was in active use from the early Bronze Age until the beginning of the Common Era. Cuneiform script ...
tablets from about 1100 to 700 BC. Alpheratz is now only considered a part of the constellation Andromeda whereas formerly the star was a part of both constellations. * The ''Bowl of Virgo'' is formed by the stars Beta, Gamma, Delta, Epsilon and Eta Virginis. Together with
Spica Spica is the brightest object in the constellation of Virgo and one of the 20 brightest stars in the night sky. It has the Bayer designation α Virginis, which is Latinised to Alpha Virginis and abbreviated Alpha Vir or α Vir. Analys ...
, they form a Y shape. * The ''Three Leaps of the Gazelle'' consists of three pairs of stars in
Ursa Major Ursa Major, also known as the Great Bear, is a constellation in the Northern Sky, whose associated mythology likely dates back into prehistory. Its Latin name means "greater (or larger) bear", referring to and contrasting it with nearby Ursa M ...
aligned in a row spanning about 30 degrees. In Arabic lore, the star pairs are pictured as the hoof prints of a gazelle startled from a pond by Leo the lion. (The "pond" is pictured as the
Coma Star Cluster The Coma Star Cluster (also known as Melotte 111 or Collinder 256) is a nearby open cluster located in the constellation Coma Berenices. The cluster contains about 40 brighter stars (between magnitudes 5 and 10) with a common proper motion. The ...
.) The first pair of stars are Xi and Nu, second pair Upsilon and Lambda, third pair Kappa and Iota Ursa Majoris. The pairs also mark three of the bear's paws. Some asterisms refer to portions of traditional constellation figures. These include: * The ''Water Jar'' or ''Urn'' of Aquarius is a Y-shaped figure centered upon Zeta Aquarii and includes Gamma, Eta and Pi. It pours water in a stream of more than 20 stars terminating with the star Fomalhaut. * The ''Crab Breast'' of
Cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...
(mentioned by
Ptolemy Claudius Ptolemy (; , ; ; – 160s/170s AD) was a Greco-Roman mathematician, astronomer, astrologer, geographer, and music theorist who wrote about a dozen scientific treatises, three of which were important to later Byzantine science, Byzant ...
) is a quadrilateral formed by the four stars Gamma, Delta, Eta and Theta Cancri which make up the carapace (inner shell) of the Crab. Contained within is the
Beehive Cluster The Beehive Cluster (also known as Praesepe (Latin for "manger", "cot" or "crib"), M44, NGC 2632, or Cr 189), is an open cluster in the constellation Cancer. One of the nearest open clusters to Earth, it contains a larger population of stars tha ...
(Messier 44) which includes Epsilon Cancri. * The ''Snake Head'' is the westernmost portion of Hydra consisting of the stars Delta, Epsilon, Zeta, Eta, Rho and Sigma Hydrae. * ''
Orion's Belt Orion's Belt is an asterism in the constellation of Orion. Other names include the Belt of Orion, the Three Kings, and the Three Sisters. The belt consists of three bright and easily identifiable collinear star systems – Alnitak, Alnilam, ...
'' consists of the three bright stars Zeta ( Alnitak), Epsilon ( Alnilam) and Delta Orionis (
Mintaka Mintaka , designation Delta Orionis (δ Orionis, abbreviated Delta Ori, δ Ori) and 34 Orionis (34 Ori), is a quintuple star system some 1,200 light-years from the Sun in the constellation of Orion. Together with Alnitak (Zeta ...
) which form the belt of Orion. * '' Orion's Sword'' which hangs from Orion's Belt consists of the stars 42 Orionis, Theta Orionis, Iota Orionis, and centered upon M42, the
Orion Nebula The Orion Nebula (also known as Messier 42, M42, or NGC 1976) is a diffuse nebula in the Milky Way situated south of Orion's Belt in the Orion (constellation), constellation of Orion, and is known as the middle "star" in the "sword" of Orion. It ...
. * The ''Bull's Face'' of
Taurus Taurus is Latin for 'bull' and may refer to: * Taurus (astrology), the astrological sign ** Vṛṣabha, in vedic astrology * Taurus (constellation), one of the constellations of the zodiac * Taurus (mythology), one of two Greek mythological ch ...
is a V-shaped figure formed by prominent members of the
Hyades Hyades may refer to: *Hyades (band) *Hyades (mythology) *Hyades (star cluster), an open star cluster in the constellation Taurus {{Disambiguation it:Iadi ...
cluster, including stars Gamma, Delta1, Delta2, Delta3, Epsilon, Theta Tauri, as well as the bright star Alpha Tauri (
Aldebaran Aldebaran () is a star in the zodiac constellation of Taurus. It has the Bayer designation α Tauri, which is Latinized to Alpha Tauri and abbreviated Alpha Tau or α Tau. Aldebaran varies in brightness from an apparent vis ...
) which forms the red eye of the Bull.


Other particular asterisms

Other asterisms are also composed of stars from one constellation, but do not refer to the traditional figures. * Four stars (
Beta Beta (, ; uppercase , lowercase , or cursive ; or ) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Ancient Greek, beta represented the voiced bilabial plosive . In Modern Greek, it represe ...
,
Upsilon Upsilon (, ; uppercase Υ, lowercase υ; ''ýpsilon'' ) or ypsilon is the twentieth letter of the Greek alphabet. In the system of Greek numerals, has a value of 400. It is derived from the phoenician alphabet, Phoenician Waw (letter), waw ...
,
Theta Theta (, ) uppercase Θ or ; lowercase θ or ; ''thē̂ta'' ; Modern: ''thī́ta'' ) is the eighth letter of the Greek alphabet, derived from the Phoenician letter Teth 𐤈. In the system of Greek numerals, it has a value of 9. Gree ...
, and
Omega Omega (, ; uppercase Ω, lowercase ω; Ancient Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the twenty-fourth and last letter in the Greek alphabet. In the Greek numerals, Greek numeric system/isopsephy (gematria), it has a value ...
Carina Carina may refer to: Places Australia * Carina, Queensland, a suburb in Brisbane * Carina Heights, Queensland, a suburb in Brisbane * Carina, Victoria, a locality in Mildura Serbia * Carina, Osečina, a village in the Kolubara District ...
e) form a well-shaped diamond – the '' Diamond Cross''. * The ''Saucepan'' or ''Pot'', being the same stars as the Belt and Sword of Orion. The end of the handle is at ι Orionis, with the far rim at η Orionis. * The four central stars in
Hercules Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures. The Romans adapted the Gr ...
,
Epsilon Epsilon (, ; uppercase , lowercase or ; ) is the fifth letter of the Greek alphabet, corresponding phonetically to a mid front unrounded vowel or . In the system of Greek numerals it also has the value five. It was derived from the Phoenic ...
(ε Her),
Zeta Zeta (, ; uppercase Ζ, lowercase ζ; , , 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 from the Phoenician alphabet, Phoenician letter zay ...
(ζ Her),
Eta Eta ( ; uppercase , lowercase ; ''ē̂ta'' or ''ita'' ) is the seventh letter of the Greek alphabet, representing the close front unrounded vowel, . Originally denoting the voiceless glottal fricative, , in most dialects of Ancient Greek, it ...
(η Her), and Pi (π Her), form the ''Keystone''. The bright globular cluster
Messier 13 Messier 13, or M13 (also designated NGC 6205 and sometimes called the Great Globular Cluster in Hercules, the Hercules Globular Cluster, or the Great Hercules Cluster), is a globular cluster of several hundred thousand stars in the constellation ...
lies along the western segment, between Zeta and Eta. * The curve of stars at the front end of the Lion from
Epsilon Epsilon (, ; uppercase , lowercase or ; ) is the fifth letter of the Greek alphabet, corresponding phonetically to a mid front unrounded vowel or . In the system of Greek numerals it also has the value five. It was derived from the Phoenic ...
(ε Leo) to
Regulus Regulus is the brightest object in the constellation Leo (constellation), Leo and one of the List of brightest stars, brightest stars in the night sky. It has the Bayer designation designated α Leonis, which is Latinisation of names, ...
(α Leo), looking much like a mirror-image question mark, has long been known as the ''Sickle''. * The brighter stars of Sagittarius form the ''Teapot''. (The Large Sagittarius Star Cloud appears to be steam emerging from the "spout".) * Northeast of the Teapot asterism lies the fainter ''Teaspoon'', consisting of the stars ξ1, ξ2, ο, π, ρ1 and ρ2 Sagitarii. * Four bright stars in
Delphinus Delphinus 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 2nd-century astronomer Pt ...
( Sualocin or α Delphini,
Rotanev Beta Delphini (β Delphini, abbreviated Beta Del, β Del) is a binary star in the constellation of Delphinus (constellation), Delphinus. It is the brightest star in Delphinus. The two components of the system are desi ...
or β Delphini, γ Delphini and δ Delphini) form ''Job's Coffin''. * The ''Terebellum'' is a small quadrilateral of four faint stars (
Omega Omega (, ; uppercase Ω, lowercase ω; Ancient Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the twenty-fourth and last letter in the Greek alphabet. In the Greek numerals, Greek numeric system/isopsephy (gematria), it has a value ...
, 59, 60, 62) in Sagittarius' hindquarters. * Just south of Pegasus, the western fish of
Pisces Pisces may refer to: *Pisces (astrology), an astrological sign Astronomy *Pisces (constellation), a constellation ** Pisces Overdensity, an overdensity of stars in the Milky Way's halo that is situated in the Pisces constellation ** Pisces II, a ...
is home to the ''Circlet'' formed from
Gamma Gamma (; uppercase , lowercase ; ) 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 normally repr ...
(γ Piscium),
Kappa Kappa (; uppercase Κ, lowercase κ or cursive ; , ''káppa'') is the tenth letter of the Greek alphabet, representing the voiceless velar plosive sound in Ancient and Modern Greek. In the system of Greek numerals, has a value of 20. It was d ...
(κ Piscium),
Lambda Lambda (; uppercase , lowercase ; , ''lám(b)da'') is the eleventh letter of the Greek alphabet, representing the voiced alveolar lateral approximant . In the system of Greek numerals, lambda has a value of 30. Lambda is derived from the Phoen ...
(λ Piscium), TX Piscium,
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 J ...
(ι Piscium), and
Theta Theta (, ) uppercase Θ or ; lowercase θ or ; ''thē̂ta'' ; Modern: ''thī́ta'' ) is the eighth letter of the Greek alphabet, derived from the Phoenician letter Teth 𐤈. In the system of Greek numerals, it has a value of 9. Gree ...
(θ Piscium). *
Dubhe Dubhe is a multiple star system in the northern constellation of Ursa Major. It is formally designated Alpha Ursae Majoris, Latinised from α Ursae Majoris, Despite being designated "α" (alpha), it is the second-brightest object ...
and Merak (Alpha and Beta Ursae Majoris), the two stars at the end of the bowl of the
Big Dipper The Big Dipper (American English, US, Canadian English, Canada) or the Plough (British English, UK, Hiberno-English, Ireland) is an asterism (astronomy), asterism consisting of seven bright stars of the constellation Ursa Major; six of them ar ...
are often called the ''Pointers'': a line from β to α and continued for about five times the distance between them arrives at the North Celestial Pole and the star
Polaris Polaris is a star in the northern circumpolar constellation of Ursa Minor. It is designated α Ursae Minoris (Latinisation of names, Latinized to ''Alpha Ursae Minoris'') and is commonly called the North Star or Pole Star. With an ...
(α UMi/Alpha Ursae Minoris), the North Star. * Rigil Kentaurus (α Centauri) and Hadar (β Centauri) are the ''Southern Pointers'' leading to the Southern Cross and thus helping to distinguish
Crux CRUX is a lightweight x86-64 Linux distribution targeted at experienced Linux users and delivered by a tar.gz-based package system with BSD-style initscripts. It is not based on any other Linux distribution. It also utilizes a ports system ...
from the False Cross.


Asterisms across multiple constellations

Other asterisms that are formed from stars in more than one constellation. * The ''Egyptian X'' is a large asterism which, like the Diamond of Virgo, is composed of a pair of equilateral triangles.
Sirius Sirius is the brightest star in the night sky. Its name is derived from the Greek word (Latin script: ), meaning 'glowing' or 'scorching'. The star is designated  Canis Majoris, Latinized to Alpha Canis Majoris, and abbr ...
(α CMa),
Procyon Procyon () is the brightest star in the constellation of Canis Minor and usually the list of brightest stars, eighth-brightest star in the night sky, with an apparent visual magnitude of 0.34. It has the Bayer designation α Canis Min ...
(α CMi), and
Betelgeuse Betelgeuse is a red supergiant star in the constellation of Orion (constellation), Orion. It is usually the List of brightest stars, tenth-brightest star in the night sky and, after Rigel, the second brightest in its constellation. It i ...
(α Ori) form one to the North ( Winter Triangle) while Sirius, Naos (ζ Pup), and Phakt (α Col) form another to the South. Unlike the Diamond, however, these triangles meet, not base-to-base, but vertex-to-vertex. The name derives from both the shape and, because the stars straddle the Celestial Equator, it is more easily seen from south of the Mediterranean than in Europe. * The ''Lozenge'' is a small diamond formed from three stars – Eltanin, Grumium, and Rastaban (Gamma, Xi, and Beta Draconis) – in the head of Draco and one – Iota Herculis – in the foot of
Hercules Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures. The Romans adapted the Gr ...
. * The diamond-shaped ''False Cross'' is composed of the four stars Alsephina (δ Velorum), Markeb (κ Velorum), Avior (ε Carinae), and Aspidiske (ι Carinae). Although its component stars are not quite as bright as those of the
Southern Cross CRUX is a lightweight x86-64 Linux distribution targeted at experienced Linux users and delivered by a tar.gz-based package system with BSD-style initscripts. It is not based on any other Linux distribution. It also utilizes a ports system to ...
, it is somewhat larger and better shaped than the Southern Cross, for which it is sometimes mistaken, causing errors in
astronavigation Celestial navigation, also known as astronavigation, is the practice of position fixing using stars and other celestial bodies that enables a navigator to accurately determine their actual current physical position in space or on the surface o ...
. Like the Southern Cross, three of its main four stars are whitish and one orange. * The ''Northern Y'' is formed by four prominent stars,
Arcturus , - bgcolor="#FFFAFA" , Note (category: variability): , , H and K emission vary. Arcturus is a red giant star in the Northern celestial hemisphere, northern constellation of Boötes, and the brightest star in the constellation. It ha ...
(α Boötis), Seginus (γ Boötis), Alphecca (α Coronae Borealis), and centered on Izar (ε Boötis). From the
United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
in particular, where there is serious
light pollution Light pollution is the presence of any unwanted, inappropriate, or excessive artificial Visible spectrum, lighting. In a descriptive sense, the term ''light pollution'' refers to the effects of any poorly implemented lighting sources, during the ...
in many areas and also
twilight Twilight is daylight illumination produced by diffuse sky radiation when the Sun is below the horizon as sunlight from the upper atmosphere is scattered in a way that illuminates both the Earth's lower atmosphere and also the Earth's surf ...
much of the night when these constellations appear, this "Y" is often visible while other stars of Boötes and Corona Borealis are not. * The ''Lightning Bolt'', aligned north to south, consists of the stars
Epsilon Pegasi Epsilon Pegasi ( Latinised from ε Pegasi, abbreviated Epsilon Peg, ε Peg), formally named Enif , is the brightest star in the northern constellation of Pegasus. With an average apparent visual magnitude of 2.4, this is a second-magnit ...
, Alpha Aquarii,
Beta Aquarii Beta Aquarii is a single yellow supergiant star in the constellation of Aquarius. It has the official name Sadalsuud () and the Bayer designation β Aquarii, abbreviated Beta Aqr or β Aqr. Based upon parallax measurements obtained duri ...
and Delta Capricorni. (It should not be confused with the so-called David Bowie "constellation".) Easily visible to naked eyes even in light polluted skies, the asterism is useful for orienting among three constellations. * The ''Serpent Bowl'' is a large curved asterism spanning 3.5 hours of right ascension, from mid-northern latitudes best seen in July and August evenings. From west to east, it includes the stars Delta, Alpha and Epsilon Serpentis, Delta, Epsilon, Upsilon, Zeta and Eta Ophiuchi, Xi Serpentis, Nu and Tau Ophiuchi, Eta and Theta Serpentis. * The ''Eagle Tail Corona'' is a flattened curved figure in the tail of Aquila and extending into Scutum. It consists of the stars 14, 15, Lambda and 12 Aquilae, Eta Scuti, HD 174208, R and Beta Scuti. The compact open cluster Messier 11 is also aligned with the curve.


Telescopic asterisms

Asterisms range from the large and obvious to the small, and even telescopic. * The ''37'' or ''LE'' of NGC 2169, in Orion. * The ''Engagement Ring'' in
Ursa Minor Ursa Minor (, contrasting with Ursa Major), also known as the Little Bear, is a constellation located in the far northern celestial hemisphere, northern sky. As with the Great Bear, the tail of the Little Bear may also be seen as the handle of ...
has the north star
Polaris Polaris is a star in the northern circumpolar constellation of Ursa Minor. It is designated α Ursae Minoris (Latinisation of names, Latinized to ''Alpha Ursae Minoris'') and is commonly called the North Star or Pole Star. With an ...
as the diamond, at one end of a ring of much fainter stars about one degree across. * The ''Broken Engagement Ring'' in
Ursa Major Ursa Major, also known as the Great Bear, is a constellation in the Northern Sky, whose associated mythology likely dates back into prehistory. Its Latin name means "greater (or larger) bear", referring to and contrasting it with nearby Ursa M ...
at 10:51 / +56°10' (preceding β Ursae Majoris, Merak). * The ''Christmas Tree'' shape of the Christmas Tree Cluster, in
Monoceros Monoceros ( Greek: , "unicorn") is a faint constellation on the celestial equator. Its definition is attributed to the 17th-century cartographer Petrus Plancius. It is bordered by Orion to the west, Gemini to the north, Canis Major to the s ...
. It is made up of about approximately 40 stars. * '' The Coathanger'', in
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 ...
, also known as ''Brocchi's Cluster'' (see image at top). * '' Kemble's Cascade'', a chain of stars that ends in open cluster NGC 1502, in
Camelopardalis Camelopardalis is a large but faint constellation of the northern sky representing a giraffe. The constellation was introduced in 1612 or 1613 by Petrus Plancius. Some older astronomy books give Camelopardalus or Camelopardus as alternative form ...
. * ''Napoleon's Hat'' (Picot 1), in Bootes (south of α Bootis, Arcturus). * ''The Ring of the Nibelungen'' (Ferrero 27) in Draco, named after the 1857 German epic drama, at 15:57 / +62°32' (near galaxy NGC 6015). * The V-shaped Messier 73 in Aquarius, determined to be an asterism in 2002.


See also

* Australian Aboriginal astronomy *
Chinese constellation Traditional Chinese astronomy has a system of dividing the celestial sphere into asterisms or constellations, known as "officials" ( Chinese ''xīng guān''). The Chinese asterisms are generally smaller than the constellations of Hellenisti ...
*
Nakshatra Nakshatra () is the term for Lunar mansion in Hindu astrology and Buddhist astrology. A nakshatra is one of 27 (sometimes also 28) sectors along the ecliptic. Their names are related to a prominent star or asterisms in or near the respective s ...


References


Bibliography

* Allen, Richard Hinckley (1969). '' Star Names: Their Lore and Meaning.'' Dover Publications Inc. (Reprint of 1899 original). . * Burnham, Robert (1978). ''Burnham's Celestial Handbook'' (3 vols). Dover Publications Inc. . * Pasachoff, Jay M. (2000). ''A Field Guide to the Stars and Planets (4th ed.).'' Houghton Mifflin Co.


External links


List of Asterisms
from deep-sky.co.uk
Naked-Eye Asterisms
from Milwaukee Astronomical Society
List of Asterisms
from deepsky.waarnemen.com
List of Asterisms
from nightskyatlas.com

from saguaroastro.org

from waynesthisandthat.com {{DEFAULTSORT:Asterism (Astronomy) Stellar groupings + Former constellations