|Right ascension||14 h 21 m 38 s to 16 h 02 m 17 s|
|declination||−29 ° 59 ′ 42 ″ to −0 ° 28 ′ 27 ″|
|Completely visible||60.3 ° N to 90 ° S|
|Observation time for Central Europe||January - (March) -
(May) - July
|Number of stars brighter than 3 mag||2|
|Brightest star (size)||Zuben-el-Shemali (2.61)|
clockwise from north )
The scales lie on the ecliptic so that the sun , moon and the planets pass through them. It therefore belongs to the signs of the zodiac . However, due to the precession movement of the earth's axis, the time of the passage of the sun has changed compared to ancient times , which is why the zodiac sign Libra no longer corresponds to the constellation Libra. The sun is currently in Libra from October 31 to November 23.
History and mythology
Already with the Sumerians the constellation was called "Libra" ( Giš-rin ), perhaps because the sun was there 4000 years ago at the time of the equinox , but perhaps also because taxes were collected at this time of the year. The tax collectors weighed the amount of grain due with beam scales.
With the Babylonians and ancient Greeks , on the other hand, the stars were assigned to the scorpion and represented its claws. Therefore the constellation was called "Chelai" (the claws) by the Greeks.
The Arab astronomers also saw part of Scorpio in the constellation. The stars β and γ formed the northern scissors, the stars α, υ and σ the southern scissors of the Scorpio.
The “southern scissors” was not assigned to Libra until 1930 when the constellation boundaries were established by the International Astronomical Union (IAU). The star σ Librae was previously called γ Scorpii.
|B.||F.||Names or other designations||size||Lj||Spectral class|
|β||27||Zuben-el-schemali (Zubeneschemali)||2.61 m||120||B8 V|
|α 2||9||Zuben-el-dschenubi (Zubenelgenubi)||2.75 m||77||A3|
|σ||20th||Brachium , Cornu||3.29 m||292||M3 III|
|θ||39||3.6 m||120||K4 III|
|τ||40||3.66 m||400||B3 V|
|γ||38||Zuben-el-Akrab||3.91 m||152||G8 IV|
|δ||13||Zuben-el-meticulousness||4.4 to 5.8 m||304||B9.5 V|
|α 1||5.13 m|
|μ||7th||5.32 m||250||A1 + A5|
|ξ 2||5.48 m|
|ξ 1||5.78 m|
The σ Librae ( Brachium ), 292 light years away, is a reddish star of the spectral class M4 III.
γ Librae is 152 light years away. The Arabic name Zuben-el-Akrab means "scorpion's scissors".
|α||2.8 / 5.2 m||231 "|
|ι||4.7 / 9.7 m||8.5 "|
|μ||5.7 m / 6.6 m||2.0 "|
α Librae is a binary star system 77 light years away. Due to the wide angular distance of 231 arc seconds , they can already be observed with prism binoculars . The system is almost exactly on the ecliptic, so it is regularly the moon covered .
The binary star system ι Librae is about 250 light years away. A telescope with an opening of 6 cm or more is required for observation .
|δ||4.9 to 5.9 m||2,327 days||Coverage variable|
Messier and NGC objects
|5897||8.6 m||Globular clusters|
Further individual objects
Worth mentioning among the stars in Libra is u. a. Gliese 581 , a red dwarf 20.5 light years away , which is about 50 times weaker than our sun ( spectral class : M3.5, visual brightness: 10.56). It has a system of at least three planetary companions ( exoplanets ).
- http://www.astronomie.de/bibliothek/artikel/sternbilder/waage.htm (star map)
- Libra constellation A photographic journey through the signs of the zodiac
- http://deepsky.astroinfo.org/Sco/m4/ (pictures of Scorpio and Libra)
- https://exoplanetarchive.ipac.caltech.edu/ (data of the exoplanets)