Algieba

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Double star
Algieba (γ Leonis)
Algieba in the constellation Leo
Observation
dates equinox :  J2000.0 , epoch : J2000.0
AladinLite
Constellation lion
Right ascension 10 h 19 m 58 s
declination + 19 ° 50 ′ 29 ″
Apparent brightness  1.98 (1.84 to 2.03) mag
Astrometry
Radial velocity (−36.7 ± 0.9) km / s
parallax (26.0 ± 0.8) mas
distance  (126 ± 4) ly
((39 ± 1) pc )
orbit 
period 510 a
Individual data
Names A / γ 1 / Algieba; B / γ 2
Observation data:
Apparent brightness A / γ 1 / Algieba 2.28 mag
B / γ 2 3.51 mag
Typing:
Spectral class A / γ 1 / Algieba K1 III
B / γ 2 G7 III
B − V color index A / γ 1 / Algieba 1.15
U − B color index A / γ 1 / Algieba 1.00
Physical Properties:
Absolute vis.
Brightness M vis 		A / γ 1 / Algieba −0.7 mag
B / γ 2 +0.6 mag
radius A / γ 1 / Algieba 23 R ☉
B / γ 2 10 R ☉
Luminosity A / γ 1 / Algieba 180 L ☉
B / γ 2 50 L ☉
Effective temperature A / γ 1 / Algieba 4500 K
B / γ 2 5000 K
Other names
and catalog entries
Bayer name γ Leonis
Flamsteed name 41 Leonis
Bonn survey BD + 20 ° 2467
Hipparcos catalog HIP 50583 [1]
Bright Star Catalog HR 4057 HR 4058
Henry Draper Catalog HD 89484 HD 89485
SAO catalog SAO 81298 SAO 81299
Tycho catalog TYC 1423-1349-1 [2] TYC 1423-1349-2 [3]
WDS catalog WDS J10199 + 1951
Further designations: Struve 1424
So far, there is hardly any data on two other components C and D.

Algieba is the name of the star γ Leonis (Gamma Leonis) in the constellation Leo . The name comes from Arabic and means something like mane of the lion .

Algieba is a possibly four-fold star system in which the two main components can be separated in small telescopes (from 5 centimeters objective diameter). The angular distance between the components is 4.4 " , the position angle 125 degrees.

The apparent brightness of the entire system is 2.0 mag, the main star alone has an apparent brightness of +2.3 mag and belongs to the spectral class K1 III. The system is generally not yet understood as the assumed masses of the stars do not match the orbital times in the system.

The brightest component (A / gam01) is about 4500 Kelvin and has 180 times the luminosity of our sun ; From this information, the diameter of the star can be estimated to be about 23 times the diameter of our sun. This star is also orbited by an object that is a massive exoplanet or possibly a brown dwarf .

The second brightest component (B / gam02) has a brightness of +3.5 mag and belongs to the spectral class G7 III.

The IAU has on 20 July 2016 the proper name Algieba as standardized proper name for the star γ 1 defined. The star γ 2 therefore has no proper name (yet).

See also

Web links

Individual evidence

  1. ↑ gam Leo. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on September 22, 2018 .
  2. ↑ a b c gam01 Leo. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on September 22, 2018 .
  3. ↑ a b NSV 4823. In: VSX. AAVSO, accessed September 22, 2018 .
  4. ↑ a b Algieba. Jim Kaler, accessed September 22, 2018 .
  5. ↑ gam01 Leo. In: Extrasolar Planets Encyclopaedia . Retrieved September 22, 2018 .
  6. ↑ Bulletin of the IAU Working Group on Star Names, No. 1, July 2016. (PDF) Retrieved November 9, 2016 (English, 184 KiB).