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Suggest pagesAlpha Librae
| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Libra |
| Right ascension | 14h 50m 41.26s |
| Declination | -15° 59' 49.5" |
| Apparent magnitude (V) | +5.15 |
| Absolute magnitude (V) | +3.28 |
| Distance | 77 ly (23.62 pc) |
| Spectral type | F3V |
| Other designations | |
| Observation data Epoch J2000.0 Equinox J2000.0 |
|
|---|---|
| Constellation | Libra |
| Right ascension | 14h 50m 52.78s |
| Declination | -16° 02' 29.8" |
| Apparent magnitude (V) | +2.75 |
| Absolute magnitude (V) | +0.88 |
| Distance | 77 ly (23.62 pc) |
| Spectral type | A3IV |
| Other designations | |
Alpha Librae (α Lib, α Librae) is the second brightest star in the constellation Libra (despite its Bayer designation as alpha). It has the traditional name Zubenelgenubi. The name, from Arabic الزبن الجنوبي (al-zuban al-janūbiyy), means "southern claw" and was coined before Libra was recognized as distinct from Scorpius. The alternate names Kiffa Australis and Elkhiffa Australis, partial Latin translations of Arabic al-kiffah al-janūbiyy, mean "southern pan (of the scales)". Another name used in older astronomy texts, equivalent to "southern scale or pan", was Lanx Australis.[2]
Contents |
[edit] Description
Alpha Librae is visual binary located approximately 77 light years from the Sun.
Its two stars are separated in the sky by an angular distance of 231" (3'51"). The position angle of the companion is 314 degrees. The brighter of the two is a white star of spectral type A3, with an apparent brightness of 2.8 and an absolute brightness of 1.1, designated Alpha-2 Librae (α2 Lib). Its companion is a type F4 star of apparent brightness 5.2 and absolute brightness 3.5, designated Alpha-1 Librae (α1 Lib).
[edit] Viewing
 Alpha Librae, on the right, is the westernmost bright star in the constellation Libra, and is very close to the ecliptic. |
α1 Lib and α2 Lib on DSS2 sky survey; 1° view Credit: AAO/STScI/WikiSky |
Alpha Librae is close to the ecliptic so it can be easily occulted by the Moon and (very rarely) by planets. The next occultation by a planet will be by Mercury on 10 November 2052.[3]
[edit] See also
[edit] References
- ^ These table provide astronomical data for each of the stellar components of the Alpha Librae system. The data were retrieved from the Simbad Astronomical Database.
- ^ Philippe La Hire, "Tabulae Astronomicae" (1727), see star table, page 13.
- ^ Peuschel, Marco (2003). "Astronomische Ereignisse der besonderen Art". Retrieved July 10, 2005.
- Kaler, Jim (2004). "STARS: Zubenelgenubi". Retrieved July 10, 2005.
- "HD 130819 -- Star in Double System". SIMBAD Astronomical Database. http://simbad.u-strasbg.fr/sim-id.pl?protocol=html&Ident=alpha1+librae&NbIdent=1&Radius=10&Radius.unit=arcmin&CooFrame=FK5&CooEpoch=2000&CooEqui=2000&output.max=all&o.catall=on&output.mesdisp=N&Bibyear1=1983&Bibyear2=2005&Frame1=FK5&Frame2=FK4&Frame3=G&Equi1=2000.0&Equi2=1950.0&Equi3=2000.0&Epoch1=2000.0&Epoch2=1950.0&Epoch3=2000.0. Retrieved 2007-01-23.
- "HD 130841 -- Variable Star". SIMBAD Astronomical Database. http://simbad.u-strasbg.fr/sim-id.pl?protocol=html&Ident=alpha2+librae&NbIdent=1&Radius=10&Radius.unit=arcmin&CooFrame=FK5&CooEpoch=2000&CooEqui=2000&output.max=all&o.catall=on&output.mesdisp=N&Bibyear1=1983&Bibyear2=2005&Frame1=FK5&Frame2=FK4&Frame3=G&Equi1=2000.0&Equi2=1950.0&Equi3=2000.0&Epoch1=2000.0&Epoch2=1950.0&Epoch3=2000.0. Retrieved 2007-01-23.z
[edit] External links
- Alpha Librae on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images
Coordinates: 
14h 50m 41.26s, −15° 59′ 49.5″
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