Libra (constellation)

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This article is about the constellation. Libra is also a Roman coin and weight measure, see Ancient Roman weights and measures. Libra is also a novel by Don DeLillo. LIBRA is also a political party in Croatia. Libra is also an album by Toni Braxton.

Libra (, and Latin for balance) is a constellation of the zodiac. It is a fairly inconspicuous constellation and has no star of first magnitude, lying between Virgo to the west and Scorpius to the east. As the names of the brighter stars testify, it was at one point part of Scorpius' claws.

Libra
Constellation
Libra
AbbreviationLib
GenitiveLibrae
Right ascension15
Declination−15
Area538 sq. deg. (29th)
Meteor showers
Bordering
constellations
Visible at latitudes between +65° and −90°.
Best visible at 21:00 (9 p.m.) during the month of June.

Notable features

The brightest stars in Libra form a rectangle:

α and β Librae are the scales' balance beam, and γ and σ are the weighing pans.

σ Librae was formerly known as γ Scorpii despite being well inside the boundaries of Libra. It was not redesignated as σ Librae until 1851 (by Benjamin A. Gould).

Mythology

The constellation, which had originally formed part of the claws of the scorpion (Scorpio), is the youngest of the Zodiac and the only one not to represent a living creature. In later Greek mythology, the constellation, which when considered on its own looks vaguely like a set of scales, was considered to depict the scales held by Astraea (identified as Virgo), the goddess of justice.

Since Libra was originally part of Virgo (as scales), and before that part of Scorpio, it was not a distinct entity for which a zodiac sign was named. Its place may have been taken by Boötes, which is the nearest to the ecliptic. Since the place Boötes should have held on the ecliptic is vacant, it may have, together with Ursa Major, Draco, and Ursa Minor, also in Libra, led to the myth of the apples of the Hesperides, one of The Twelve Labours of Herakles.

Astrology

The Western astrological sign Libra of the tropical zodiac (September 23October 22) differs from the astronomical constellation and the Hindu astrological sign of the sidereal zodiac (October 31November 22).

In some cosmologies, Libra is associated with the classical element Air, and thus called an Air Sign (with Aquarius and Gemini). It is also one of the four cardinal signs (along with Aries, Cancer, and Capricorn). Its polar opposite is Aries. It is the domicile of Venus and the exaltation of Saturn. Each astrological sign is assigned a part of the body, viewed as the seat of its power. Libra rules the lower back and internal reproductive organs. The symbol for Libra is the Scales.

Stars

Stars with proper names:
  • (α Lib) Zubenelgenubi [Zuben Elgenubi] or Kiffa Australis [Elkhiffa australis] (8/α1 Lib, 9/α2 Lib) – double 5.15, 2.75
    < الزبن الجنوبي az-zuban al-janūbiyy The southern claw (of the scorpion)
    < ? al-kiffah al-janūbiyy The southern pan (of the scales)
  • (27/β Lib) 2.61 Zubeneschamali [Zuben Eschamali, Zuben el Chamali, Zubenesch, Zubenelg] or Kiffa Borealis
    < الزبن الشمالي az-zuban aš-šamāliyy The northern claw (of the scorpion)
    < ? al-kiffah aš-šamāliyy The northern pan (of the scales)
  • (38/γ Lib) 3.91 Zuben Elakrab [Zuben (el) Hakrabi, Zuben Hakraki]
    < زبن العقرب zuban al-caqrab The claw of the scorpion
Stars with Bayer designations:
ε Lib 4.92; ζ Lib 5.53; θ Lib 4.13; ι Lib 4.54; κ Lib 4.75; λ Lib 5.04; μ Lib 5.32; ξ1 Lib 5.78; ξ2 Lib 5.48; ο Lib 6.14; τ Lib 3.66; υ Lib 3.60
Stars with Flamsteed designations:
2 Lib 6.22; 4 Lib 5.70; 5 Lib 6.33; 11 Lib 4.93; 12 Lib 5.27; 16 Lib 4.47; 17 Lib 6.61; 18 Lib 5.88; 22 Lib 6.41; 23 Lib 6.47 – has a planet; 25 Lib 6.07; 26 Lib 6.18; 28 Lib 6.16; 30 Lib 6.46; 32 Lib 5.64; 33 Lib 6.69; 34 Lib 5.82; 36 Lib 5.13; 37 Lib 4.61; 41 Lib 5.36; 42 Lib 4.97; 47 Lib 5.95; 48 Lib 4.95; 49 Lib 5.47; 50 Lib 5.53
Other notable stars:
HR 5568