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Leo (constellation)
Encyclopedia
Leo is one of the constellation
s of the zodiac
. Its name is Latin
for lion
. Its symbol is
. Leo lies between dim Cancer
to the west and Virgo
to the east.
(α Leonis); the lion's tail, Denebola
(β Leonis); and γ1 Leonis
(Algieba). Many other fainter stars have been named as well, such as δ Leo (Zosma), θ Leo (Chort), κ Leo (Al Minliar al Asad), λ Leo
(Alterf), and ο Leo
(Subra).
Regulus, Al Jabbah
, and Algieba
, together with the fainter stars ζ Leo
(Adhafera), μ Leo
(Ras Elased Borealis), and ε Leo
(Ras Elased Australis), make up the asterism
known as the Sickle. These stars represent the head and the mane of the lion.
The star Wolf 359, one of the nearest stars to Earth (7.78 light-year
s), is in Leo. Gliese 436, a faint star in Leo about 33 light years away from the Sun, is orbited by a transiting Neptune-mass extrasolar planet
.
The carbon star
CW Leo (IRC +10216
) is the brightest star in the night sky at the infrared N-band (10 μm wavelength).
, Messier 65
, Messier 66
, Messier 95
, Messier 96
, Messier 105
, and NGC 3628
are the most famous, the first two being part of the Leo Triplet
.
The Leo Ring
, a cloud of hydrogen and helium gas, is found in orbit of two galaxies found within this constellation.
In Greek mythology
, Leo was identified as the Nemean Lion
which was killed by Hercules
during one of his twelve labours, and subsequently put into the sky.
The Roman poet Ovid
called it Herculeus Leo and Violentus Leo. Bacchi Sidus (star of Bacchus
) was another of its titles, the god Bacchus
always being identified with this animal. However, Manilius
called it Jovis et Junonis Sidus (Star of Jupiter
and Juno
).
Early Hindu astronomers knew it as Asleha and as Sinha, the Tamil
Simham.
from July 22 to August 22, and in sidereal astrology
, from August 16 to September 15.
Leo is commonly represented as if the sickle-shaped asterism
of stars is the back of the Lion's head.
H.A. Rey has suggested an alternative way to connect the stars, which graphically shows a lion
walking. The stars delta Leonis, gamma Leonis
, eta Leonis
, and theta Leonis form the body
of the lion, with gamma Leonis being of the second magnitude and delta Leonis and theta Leonis being of the third magnitude. The stars gamma Leonis, zeta Leonis
, mu Leonis
, epsilon Leonis
, and eta Leonis
form the lion's neck
, with epsilon Leonis being of the third magnitude. The stars mu Leonis, kappa Leonis
, lambda Leonis
, and epsilon Leonis form the head
of the lion. Delta Leonis and beta Leonis form the lion's tail
: beta Leonis, also known as Denebola
, is the bright tip of the tail with a magnitude of two. The stars theta Leonis, iota Leonis
, and sigma Leonis
form the left hind leg
of the lion, with sigma Leonis being the foot. The stars theta Leonis and rho Leonis
form the right hind leg, with rho Leonis being the foot. The stars eta Leonis
and alpha Leonis
mark the lion's heart, with alpha Leonis, also known as Regulus
, being the bright star of magnitude one. The stars eta Leonis and omicron Leonis
form the right front foot of the Lion.
was a United States Navy
Crater class cargo ship
named after the Latin version of this constellation name.
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
s of the zodiac
Zodiac
In astronomy, the zodiac is a circle of twelve 30° divisions of celestial longitude which are centred upon the ecliptic: the apparent path of the Sun across the celestial sphere over the course of the year...
. Its name is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for lion
Lion
The lion is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger...
. Its symbol is
. Leo lies between dim CancerCancer (constellation)
Cancer is one of the twelve constellations of the zodiac. Its name is Latin for crab and it is commonly represented as such. Its symbol is . Cancer is small and its stars are faint...
to the west and Virgo
Virgo (constellation)
Virgo is one of the constellations of the zodiac. Its name is Latin for virgin, and its symbol is . Lying between Leo to the west and Libra to the east, it is the second largest constellation in the sky...
to the east.
Stars
Leo contains many bright stars, such as RegulusRegulus
Regulus is the brightest star in the constellation Leo and one of the brightest stars in the night sky, lying approximately 77.5 light years from Earth. Regulus is a multiple star system composed of four stars which are organized into two pairs...
(α Leonis); the lion's tail, Denebola
Denebola
Denebola is the second brightest star in the constellation Leo. It is an A-class star that is about distant from earth, and has a luminosity about twelve times that of the sun. Its apparent magnitude is 2.14...
(β Leonis); and γ1 Leonis
Gamma Leonis
Gamma Leonis is a binary star system in the constellation Leo. It has the traditional name Algieba or Al Gieba.-Name origin and history:...
(Algieba). Many other fainter stars have been named as well, such as δ Leo (Zosma), θ Leo (Chort), κ Leo (Al Minliar al Asad), λ Leo
Lambda Leonis
Lambda Leonis is a star in the constellation Leo. It has the traditional name Alterf, from the Arabic الطرف "the view "....
(Alterf), and ο Leo
Omicron Leonis
Omicron Leonis is a binary star in the constellation Leo. It has the traditional name Subra.The two stars of Subra are of spectral class F9III for the primary and A5mV for the secondary. Their combined apparent magnitude is +3.53....
(Subra).
Regulus, Al Jabbah
Eta Leonis
Eta Leonis is a fourth-magnitude star in the constellation Leo.- Properties :Eta Leonis is a white supergiant with the stellar classification A0Ib. Though its apparent magnitude is 3.51, making it a relatively dim star to the naked eye, it is 5,600 times more luminous than the Sun, with an...
, and Algieba
Gamma Leonis
Gamma Leonis is a binary star system in the constellation Leo. It has the traditional name Algieba or Al Gieba.-Name origin and history:...
, together with the fainter stars ζ Leo
Zeta Leonis
Zeta Leonis is a fourth-magnitude star in the constellation Leo. It has the traditional name Adhafera , from the Arabic الضفيرة al-ðafīrah "the braid/curl", a reference clearly to its position in the lion's mane.- Properties :Adhafera is a rare F Class giant star with stellar classification F0III...
(Adhafera), μ Leo
Mu Leonis
Mu Leonis is a star in the constellation Leo. It has the traditional names Rasalas and Alshemali, abbreviations of Ras al Asad al Shamaliyy, from the Arabic رأس الأسد الشمالي ra’s al-’asad aš-šamālī "the northern of the lion's head".Mu Leonis is of spectral class K3 and apparent magnitude +4.1...
(Ras Elased Borealis), and ε Leo
Epsilon Leonis
Epsilon Leonis is the fifth brightest star in the constellation Leo, consistent with its Bayer designation Epsilon...
(Ras Elased Australis), make up the asterism
Asterism (astronomy)
In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...
known as the Sickle. These stars represent the head and the mane of the lion.
The star Wolf 359, one of the nearest stars to Earth (7.78 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s), is in Leo. Gliese 436, a faint star in Leo about 33 light years away from the Sun, is orbited by a transiting Neptune-mass extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
.
The carbon star
Carbon star
A carbon star is a late-type star similar to a red giant whose atmosphere contains more carbon than oxygen; the two elements combine in the upper layers of the star, forming carbon monoxide, which consumes all the oxygen in the atmosphere, leaving carbon atoms free to form other carbon compounds,...
CW Leo (IRC +10216
IRC +10216
IRC +10216 or CW Leonis is a well-studied carbon star that is embedded in a thick dust envelope. It was first discovered in 1969 by a group of astronomers led by Eric Becklin, based upon infrared observations made with the Caltech Infrared Telescope at Mount Wilson Observatory. Its energy is...
) is the brightest star in the night sky at the infrared N-band (10 μm wavelength).
Deep sky objects
Leo contains many bright galaxiesGalaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...
, Messier 65
Messier 65
Messier 65 is an intermediate spiral galaxy about 35 million light-years away in the constellation Leo. It was discovered by Charles Messier in 1780. M65, M66, and NGC 3628 comprise the famous Leo Triplet, a small group of galaxies.-Discovery:M65 was discovered by Charles Messier and included in...
, Messier 66
Messier 66
Messier 66 is an intermediate spiral galaxy about 36 million light-years away in the constellation Leo. It was discovered by Charles Messier in 1780...
, Messier 95
Messier 95
Messier 95 is a barred spiral galaxy about 38 million light-years away in the constellation Leo. It was discovered by Pierre Méchain in 1781, and catalogued by Charles Messier four days later.-Nucleus:...
, Messier 96
Messier 96
Messier 96 is an intermediate spiral galaxy about 31 million light-years away in the constellation Leo. It was discovered by Pierre Méchain in 1781.-M96 Group:...
, Messier 105
Messier 105
Messier 105 is an elliptical galaxy in the constellation Leo. Messier 105 is known to have a supermassive black hole.-History:...
, and NGC 3628
NGC 3628
NGC 3628, also known as Sarah's Galaxy, is an unbarred spiral galaxy about 35 million light-years away in the constellation Leo. It was discovered by William Herschel in 1784. It has an approximately 300,000 light-years long tidal tail. NGC 3628 along with M65 and M66 form the famous Leo...
are the most famous, the first two being part of the Leo Triplet
Leo Triplet
The Leo Triplet is a small group of galaxies about 35 million light-years away in the constellation Leo. This galaxy group consists of the spiral galaxies M65, the M66, and the NGC 3628.-Members:...
.
The Leo Ring
Leo Ring
The Leo Ring is an immense primordial cloud of hydrogen and helium gas in orbit of two galaxies within the constellation of Leo.Radio astronomers discovered the cloud in 1983...
, a cloud of hydrogen and helium gas, is found in orbit of two galaxies found within this constellation.
History and mythology
The Persians called Leo Ser or Shir; the Turks, Artan; the Syrians, Aryo; the Jewish, Arye; the Indians, Simha, all meaning "lion". In Babylonian astronomy the constellation was called UR.GU.LA - the 'Great Lion'; the bright star, Regulus, that stands at the Lion's breast also had distinctly regal associations as it was known as the King Star.In Greek mythology
Greek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
, Leo was identified as the Nemean Lion
Nemean Lion
The Nemean lion was a vicious monster in Greek mythology that lived at Nemea. It was eventually killed by Heracles. It could not be killed with mortal weapons because its golden fur was impervious to attack...
which was killed by Hercules
Heracles
Heracles ,born Alcaeus or Alcides , was a divine hero in Greek mythology, the son of Zeus and Alcmene, foster son of Amphitryon and great-grandson of Perseus...
during one of his twelve labours, and subsequently put into the sky.
The Roman poet Ovid
Ovid
Publius Ovidius Naso , known as Ovid in the English-speaking world, was a Roman poet who is best known as the author of the three major collections of erotic poetry: Heroides, Amores, and Ars Amatoria...
called it Herculeus Leo and Violentus Leo. Bacchi Sidus (star of Bacchus
Dionysus
Dionysus was the god of the grape harvest, winemaking and wine, of ritual madness and ecstasy in Greek mythology. His name in Linear B tablets shows he was worshipped from c. 1500—1100 BC by Mycenean Greeks: other traces of Dionysian-type cult have been found in ancient Minoan Crete...
) was another of its titles, the god Bacchus
Dionysus
Dionysus was the god of the grape harvest, winemaking and wine, of ritual madness and ecstasy in Greek mythology. His name in Linear B tablets shows he was worshipped from c. 1500—1100 BC by Mycenean Greeks: other traces of Dionysian-type cult have been found in ancient Minoan Crete...
always being identified with this animal. However, Manilius
Marcus Manilius
Marcus Manilius was a Roman poet, astrologer, and author of a poem in five books called Astronomica.-Criticism:The author of Astronomica is neither quoted nor mentioned by any ancient writer. Even his name is uncertain, but it was probably Marcus Manilius; in the earlier books the author is...
called it Jovis et Junonis Sidus (Star of Jupiter
Jupiter (mythology)
In ancient Roman religion and myth, Jupiter or Jove is the king of the gods, and the god of the sky and thunder. He is the equivalent of Zeus in the Greek pantheon....
and Juno
Juno (mythology)
Juno is an ancient Roman goddess, the protector and special counselor of the state. She is a daughter of Saturn and sister of the chief god Jupiter and the mother of Mars and Vulcan. Juno also looked after the women of Rome. Her Greek equivalent is Hera...
).
Early Hindu astronomers knew it as Asleha and as Sinha, the Tamil
Tamil language
Tamil is a Dravidian language spoken predominantly by Tamil people of the Indian subcontinent. It has official status in the Indian state of Tamil Nadu and in the Indian union territory of Pondicherry. Tamil is also an official language of Sri Lanka and Singapore...
Simham.
Astrology
, the Sun appeared in the constellation Leo from August 10 to In tropical astrology, the Sun is considered to be in the sign LeoLeo (astrology)
Leo is the fifth astrological sign of the Zodiac, originating from the constellation of Leo. In astrology, Leo is considered to be a "masculine", positive sign. It is also considered a fire sign and is one of four fixed signs ruled by the Sun.Individuals born when the Sun is in this sign are...
from July 22 to August 22, and in sidereal astrology
Sidereal astrology
Sidereal and tropical are astronomical terms used to describe two different definitions of a "year". They are also used as terms for two systems of ecliptic coordinates used in astrology....
, from August 16 to September 15.
Visualizations
Asterism (astronomy)
In astronomy, an asterism is a pattern of stars recognized on Earth's night sky. It may form part of an official constellation, or be composed of stars from more than one. Like constellations, asterisms are in most cases composed of stars which, while they are visible in the same general direction,...
of stars is the back of the Lion's head.
Lion
The lion is one of the four big cats in the genus Panthera, and a member of the family Felidae. With some males exceeding 250 kg in weight, it is the second-largest living cat after the tiger...
walking. The stars delta Leonis, gamma Leonis
Gamma Leonis
Gamma Leonis is a binary star system in the constellation Leo. It has the traditional name Algieba or Al Gieba.-Name origin and history:...
, eta Leonis
Eta Leonis
Eta Leonis is a fourth-magnitude star in the constellation Leo.- Properties :Eta Leonis is a white supergiant with the stellar classification A0Ib. Though its apparent magnitude is 3.51, making it a relatively dim star to the naked eye, it is 5,600 times more luminous than the Sun, with an...
, and theta Leonis form the body
Body
With regard to living things, a body is the physical body of an individual. "Body" often is used in connection with appearance, health issues and death...
of the lion, with gamma Leonis being of the second magnitude and delta Leonis and theta Leonis being of the third magnitude. The stars gamma Leonis, zeta Leonis
Zeta Leonis
Zeta Leonis is a fourth-magnitude star in the constellation Leo. It has the traditional name Adhafera , from the Arabic الضفيرة al-ðafīrah "the braid/curl", a reference clearly to its position in the lion's mane.- Properties :Adhafera is a rare F Class giant star with stellar classification F0III...
, mu Leonis
Mu Leonis
Mu Leonis is a star in the constellation Leo. It has the traditional names Rasalas and Alshemali, abbreviations of Ras al Asad al Shamaliyy, from the Arabic رأس الأسد الشمالي ra’s al-’asad aš-šamālī "the northern of the lion's head".Mu Leonis is of spectral class K3 and apparent magnitude +4.1...
, epsilon Leonis
Epsilon Leonis
Epsilon Leonis is the fifth brightest star in the constellation Leo, consistent with its Bayer designation Epsilon...
, and eta Leonis
Eta Leonis
Eta Leonis is a fourth-magnitude star in the constellation Leo.- Properties :Eta Leonis is a white supergiant with the stellar classification A0Ib. Though its apparent magnitude is 3.51, making it a relatively dim star to the naked eye, it is 5,600 times more luminous than the Sun, with an...
form the lion's neck
Neck
The neck is the part of the body, on many terrestrial or secondarily aquatic vertebrates, that distinguishes the head from the torso or trunk. The adjective signifying "of the neck" is cervical .-Boner anatomy: The cervical spine:The cervical portion of the human spine comprises seven boney...
, with epsilon Leonis being of the third magnitude. The stars mu Leonis, kappa Leonis
Kappa Leonis
Kappa Leonis is a 4th-magnitude double star in the constellation Leo. It was known as Minchir el-asad on Bode's large star atlas, Uranographia. This name is derived from the Arabic Minkhir al-Asad, "the Muzzle of the Lion" for this star...
, lambda Leonis
Lambda Leonis
Lambda Leonis is a star in the constellation Leo. It has the traditional name Alterf, from the Arabic الطرف "the view "....
, and epsilon Leonis form the head
Head
In anatomy, the head of an animal is the rostral part that usually comprises the brain, eyes, ears, nose and mouth . Some very simple animals may not have a head, but many bilaterally symmetric forms do....
of the lion. Delta Leonis and beta Leonis form the lion's tail
Tail
The tail is the section at the rear end of an animal's body; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, reptiles, and birds...
: beta Leonis, also known as Denebola
Denebola
Denebola is the second brightest star in the constellation Leo. It is an A-class star that is about distant from earth, and has a luminosity about twelve times that of the sun. Its apparent magnitude is 2.14...
, is the bright tip of the tail with a magnitude of two. The stars theta Leonis, iota Leonis
Iota Leonis
Iota Leonis is a star in the constellation Leo.It was known as 太微右垣三, "the Third of the Right Wall of the Supreme Palace Enclosure" or 次將 , "the Vice-General", in traditional Chinese astronomy...
, and sigma Leonis
Sigma Leonis
Sigma Leonis is a blue-white 4th-magnitude star in the constellation Leo.Sigma Leonis is of the spectral class B9.5Vs and has an apparent magnitude of +4.04....
form the left hind leg
Leg
Łęg may refer to the following places in Poland:*A former name for the town of Ełk *Part of the Czyżyny district of Kraków*Łęg, Pleszew County in Greater Poland Voivodeship...
of the lion, with sigma Leonis being the foot. The stars theta Leonis and rho Leonis
Rho Leonis
Rho Leonis is a blue-white 4th-magnitude star in the constellation Leo.Rho Leonis is a supergiant star with a spectral class of B1Iab and has an apparent magnitude of +3.84. It is located at an estimated distance of 870 parsecs, and is 690 parsecs above the plane of the Milky Way galaxy...
form the right hind leg, with rho Leonis being the foot. The stars eta Leonis
Eta Leonis
Eta Leonis is a fourth-magnitude star in the constellation Leo.- Properties :Eta Leonis is a white supergiant with the stellar classification A0Ib. Though its apparent magnitude is 3.51, making it a relatively dim star to the naked eye, it is 5,600 times more luminous than the Sun, with an...
and alpha Leonis
Alpha Leonis
Alpha Leonis is an American indie rock band from Portland, Oregon carried on Planet Ceres Enterprises. The band began as the solo project of Atticus Reynard, who released the album "Shadows of Men" on January 5, 2010.-Members:Current...
mark the lion's heart, with alpha Leonis, also known as Regulus
Regulus
Regulus is the brightest star in the constellation Leo and one of the brightest stars in the night sky, lying approximately 77.5 light years from Earth. Regulus is a multiple star system composed of four stars which are organized into two pairs...
, being the bright star of magnitude one. The stars eta Leonis and omicron Leonis
Omicron Leonis
Omicron Leonis is a binary star in the constellation Leo. It has the traditional name Subra.The two stars of Subra are of spectral class F9III for the primary and A5mV for the secondary. Their combined apparent magnitude is +3.53....
form the right front foot of the Lion.
Namesakes
USS Leonis (AK-128)USS Leonis (AK-128)
USS Leonis was a in service with the United States Navy in World War II. It was the only ship of the Navy to have borne this name, the Latin form of the northern constellation Leo....
was a United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
Crater class cargo ship
Crater class cargo ship
Crater-class cargo ship is a category of freighter that was constructed for use by the United States Navy during World War II under Maritime Commission EC2-S-C1 type....
named after the Latin version of this constellation name.
Observer links
- The Deep Photographic Guide to the Constellations: Leo
- Information from Windows to the Universe
- Star Map of Leo and Information from Students for Exploration and Development of Space
- Information about Leo from Chris Dolan
- Information from StarDate Online
- Leo's skymap and information from Gary Madison
- Star Map of Leo and basic information
- Pictures, Sky Map and detailed information from StarrySkies