Leo (constellation)

Leo
Constellation

List of stars in Leo
Abbreviation Leo
Genitive Leonis
Pronunciation /ˈl/, genitive /lˈnɨs/
Symbolism the Lion
Right ascension 11 h
Declination +15°
Quadrant NQ2
Area 947 sq. deg. (12th)
Main stars 9, 15
Bayer/Flamsteed
stars
92
Stars with planets 11
Stars brighter than 3.00m 5
Stars within 10.00 pc (32.62 ly) 1
Brightest star Regulus (α Leo) (1.35m)
Nearest star Wolf 359
(7.78 ly, 2.39 pc)
Messier objects 5
Meteor showers Leonids
Bordering
constellations
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 ( /ˈl/) is one of the constellations 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.

Contents

Notable features

Stars

Leo contains many bright stars, such as Regulus (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-years), 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.[1]

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

Deep-sky objects

Leo contains many bright galaxies, 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.

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.[2]

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.

Astrology

As of 2002, the Sun appeared in the constellation Leo from August 10 to In tropical astrology, the Sun is considered to be in the sign Leo from July 22 to August 22, and in sidereal astrology, from August 16 to September 15.

Visualizations

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.[3]

Namesakes

USS Leonis (AK-128) was a United States Navy Crater class cargo ship named after the Latin version of this constellation name.

Citations

  1. ^ "Astronomers discover smallest "exoplanets" yet". Toronto. http://www.theglobeandmail.com/servlet/story/RTGAM.20040831.wplanet20831a/BNStory/specialScienceandHealth. 
  2. ^ Babylonian Star-lore by Gavin White, Solaria Pubs, 2008 page 140
  3. ^ H. A. Rey, The Stars — A New Way To See Them. Enlarged World-Wide Edition. Houghton Mifflin, Boston, 1997. ISBN 0-395-24830-2.

References

External links

Media related to [//commons.wikimedia.org/wiki/Category:Leo_(constellation) Leo (constellation)] at Wikimedia Commons

Observer links

Science

Myths

Coordinates: 11h 00m 00s, +15° 00′ 00″