Leo (constellation)

2007 Schools Wikipedia Selection. Related subjects: Space (Astronomy)

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Abbreviation Leo
Genitive Leonis
Symbology the Lion
Right ascension 11 h
Declination 15°
Area 947 sq. deg.
Ranked 12th
Number of stars 68
Number of bright stars

( magnitude < 3)

Number of nearby stars

( Distance < 100 ly)

Brightest star Regulus (α Leo)
( App. magnitude 1.4)
Nearest Star Denebola (β Leo)
( Distance: 36.2 ly)
Meteor showers
  • Leonids
  • Ursa Major
  • Leo Minor
  • Lynx (corner)
  • Cancer
  • Hydra
  • Sextans
  • Crater
  • Virgo
  • Coma Berenices
Visible at latitudes between +90° and −65°
Best visible at 21:00 (9 p.m.) during the month of April

Leo ( IPA: /ˈliəʊ/, Latin: lion, symbol , Unicode ♌) is a constellation of the zodiac. Leo lies between dim Cancer to the west and Virgo to the east.

Notable features

This constellation contains many bright stars, such as Regulus (α Leonis), the lion's heart; 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, η Leonis, and γ Leonis, 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.

A former asterism representing the tuft of the lion's tail was made its own constellation by Ptolemy III in 240 BC. It was given the name Coma Berenices.

The star Wolf 359, one of the nearest stars to Earth (7.7 light-years), is in Leo. Gliese 436, a faint star in Leo about 33 light years away from the Sun, is orbited by one of the smallest extrasolar planets ever found.

The carbon star CW Leo ( IRC +10216) is the brightest star in the night sky at the infrared N-band (10 μm wavelength).

Notable deep sky objects

Leo contains many bright galaxies, of which the twins ( Spiral Galaxy M65, Spiral Galaxy M66) and ( Spiral Galaxy M95, Spiral Galaxy M96) are the most famous.



Early Hindu astronomers knew it as Asleha and as Sinha, the Tamil Simham but later, influenced by Greece and Rome, as Leya or Leyaya, from the word Leo, as the Romans commonly called it.

Ovid wrote it as Herculeus Leo and Violentus Leo. Bacchi Sidus (Star of Bacchus) was another of its titles, the god always being identified with this animal, and its shape the one often adopted by him in his numerous transformations, while a lion's skin was his frequent dress. But Manilius had it Jovis et Junonis Sidus (Star of Jove and Juno), as being under the guardianship of these deities, perhaps appropriately considering its regal character, especially that of its lucida.

The Persians called it Ser or Shir; the Turks, Artan; the Syrians, Aryo; the Jews, Arye; the Indians, "Sher"; and the Babylonians, Aru — all meaning a lion. In Euphratean astronomy it was additionally known as Gisbar-namru-sa-pan, variously translated, but by Bertin, as the Shining Disc which precedes Bel, "Bel" being our Ursa Major, or in some way intimately connected therewith.


Hevelius' drawing of Leo, 1690
Hevelius' drawing of Leo, 1690

The adoption of this animal's form for the zodiac sign has been attributed to the fact that when the Sun was among its stars in midsummer the lions of the desert left their accustomed haunts for the banks of the Nile, where they could find relief from the heat in the waters of the inundation. Pliny wrote that the Egyptians worshipped the stars of Leo because the rise of their great river was coincident with the Sun's entrance among them. For the same reason the Sphinx is said to have been sculpted with Leo's body and the head of the adjacent Virgo, although Egyptologists maintain that this head represented one of the early kings, or the god Harmachis.

Distinct reference is made to Leo in an inscription of the walls of the Ramesseum at Thebes, which, like the Nile temples generally, was adorned with the animal's bristles, while on the planisphere of Dendera its figure is shown standing on an outstretched serpent. The Egyptian stellar Lion, however, comprised only a part of ours, and in the earliest records some of its stars were shown as a knife, as they now are as a sickle. Kircher gave its title there as Πιμεντεκεων, Cubitus Nili.

The astrological symbol has been supposed to portray the animal's mane, but it also might be the animal's tail. Gaius Julius Hyginus's writing published in 1488 and Albumasar's in 1489 showing this latter member of extraordinary length, twisting between the hind legs and over the back, Hyginus's manuscript properly locating the star Denebola in the end. But the International Dictionary says that this symbol is a corruption of the initial letter of Λεων (Leon). Félix Lajard's Cultes de Mithra mentions the hieroglyph of Leo as among the symbols of Mithraic worship, but how their Lion agreed, if at all, with ours is not known.


In Greek mythology, it was identified as the Nemean Lion (and may have been a source of the tale) which was killed by Heracles during one of his twelve labours, and subsequently put into the sky.


The Western astrological sign Leo of the tropical zodiac ( July 23 – August 23) differs from the astronomical constellation and the Hindu astrological sign of the sidereal zodiac ( August 10 – September 15).

In some cosmologies, Leo is associated with the classical element Fire, and thus called a Fire Sign (with Aries and Sagittarius). Leo is also one of the Fixed signs (along with Taurus, Scorpio, and Aquarius).

It is the domicile of the Sun. The Egyptian pharaoh Nechepso, and his priest Petosiris, taught that at the creation of the world the Sun rose here near Denebola, and hence Leo was Domicilium Solis, the emblem of fire and heat, and the "House of the Sun".

Each astrological sign is assigned a part of the body, viewed as the seat of its power. Leo rules the heart and spine.


In the symbolism of alchemy, Leo denoted the absorption or assimilation of one substance by another.

Graphic visualization

Diagram of an alternate way to connect the stars of the constellation Leo.  The lion is shown walking.
Diagram of an alternate way to connect the stars of the constellation Leo. The lion is shown walking.

The stars of the constellation Leo can be connected in an alternative way, 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.

The stars 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 form the left front foot, with alpha Leonis, also known as Regulus, being the bright foot of magnitude one. The stars eta Leonis and omicron Leonis form the right front foot of the Lion.

In popular culture

  • Leo was one of four constellations depicted in a United States Postal Service commemorative stamp issue of October 2005 entitled "Constellations".
  • Leo is the insignia of the US Navy fighter squadron VF-213 Black Lions.


Stars with proper names:
  • Regulus or Cor Leonis or Qalb [Kabelaced, Qalb al-Asad] or Rex (32/α Leo) 1.36
    < rēgulus The prince
    < cor leōnis The heart of the lion
    < قلب الأسد Qalb ul-Āsad The heart of the lion
  • (94/β Leo) 2.14 Denebola [Deneb Alased, Deneb Aleet]
    < ذنب الأسد Ðanab ul-Āsad The tail of the lion
  • ( 41/γ1 Leo) 2.01 Algieba [Al Gieba, Algeiba]
    < الجبهة al-jabha[h] The forehead
    (or much less likely from Arabicized Latin juba The mane)
  • ( 68/δ Leo) 2.56 Zosma [Zozma, Zozca, Zosca, Zubra] or Duhr [Dhur]
  • ( 17/ε Leo) 2.97 Ras Elased [Ras Elased Australis] or Algenubi
    < رأس الأسد الجنوبي Rās al-Āsad al-Janūbii The southern one of the lion head
  • ( 36/ζ Leo) 3.43 Adhafera [Aldhafera, Aldhafara]
    < الضفيرة Al-Ðafīrah The braid/curl (of the mane)
  • ( 30/η Leo) 3.48 Al Jabhah
    < الجبهة al-jabha[h] The Front or The Forehead
  • ( 70/θ Leo) 3.33 Chertan [Chort] or Coxa
    < ? al-xarat The rib (two small ribs?)
    < cōxa The hip
  • ( 78/ι Leo) 4.00 Tsze Tseang
    < 次將 (Mandarin cìjiàŋ) The vice-general
  • ( 1/κ Leo) 4.47 Al Minliar al Asad
    < Muzzle (or Nose) of the Lion
  • ( 4/λ Leo) 4.32 Alterf or Al Terf
    < الطرف AŢ-Ţarf The eye, the glance (of the lion)
  • ( 24/μ Leo) 3.88 Rasalas [Ras Elased Borealis, Ras al Asad al Shamaliyy] or Alshemali
    < رأس الأسد الشمالي Ra's ul-Āsad il-Šamālii The northern one of the lion head
  • ( 14/ο Leo) — double 3.52, 3.7 Subra
Stars with Bayer designations:
  • ( 47/ρ Leo) 3.84 Shir or Ser
    < shir Persian for "lion"
  • ( 77/σ Leo) 4.05 Shishimai
    < 獅子舞 shishimai Lion Dance
41/γ2 Leo 3.80; 27/ν Leo 5.26; 5/ξ Leo 4.99; 29/π Leo 4.68; 84/τ Leo 4.95; 91/υ Leo 4.30; 63/χ Leo 4.62; 74/φ Leo 4.45; 16/ψ Leo 5.36; 2/ω Leo 5.40
Stars with Flamsteed designations:
3 Leo 5.72; 7 Leo 6.32; 8 Leo 5.73; 9 Leo 6.61; 10 Leo 5.00; 11 Leo 6.63; 13 Leo 6.26; 18 Leo 5.67; 19 Leo 6.44; 20 Leo 6.10; 23 Leo 6.45; 34 Leo 6.43; 35 Leo 5.95; 37 Leo 5.42; 39 Leo 5.81; 40 Leo 4.78; 42 Leo 6.16; 43 Leo 6.06; 44 Leo 5.61; 45 Leo 6.01; 46 Leo 5.43; 48 Leo 5.07; 49 Leo 5.67; 54 Leo – double 4.30, 6.30; 55 Leo 5.91; 56 Leo 5.91; 64 Leo 6.48; 67 Leo 5.70; 71 Leo 7.31; 72 Leo 4.56; 75 Leo 5.18; 76 Leo 5.90; 79 Leo 5.39; 80 Leo 6.35; 81 Leo 5.58; 83 Leo – double 6.49, 7.57; comp. B has a planet; 85 Leo 5.74; 86 Leo 5.54; 88 Leo 6.27; 89 Leo 5.76; 90 Leo 5.95; 92 Leo 5.26; 93 Leo 4.50
Other notable stars:
  • Wolf 359 13.45 — flare star; 3rd closest star
  • GJ 436 10.68 — nearby; has a planet
  • HD 88133 8.06 — has a planet
  • CW Leonis is the brightest star at N-band (10 μm wavelength)

Astronomy | Constellations of the Zodiac | Astrology

Aries Taurus Gemini Cancer Leo Virgo Libra Scorpius Ophiuchus Sagittarius Capricornus Aquarius Pisces

Constellations changed by Johann Bayer in the 1603 text Uranometria

Centaurus | split into | Centaurus | Crux
Leo | split into | Leo | Coma Berenices
Piscis Austrinus | split into | Piscis Austrinus | Grus
Sagittarius | split into | Sagittarius | Corona Australis
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