Lambda Scorpii

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Multiple star
λ Scorpii (Shaula)
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Scorpio
Right ascension 17 h 33 m 36.5 s
declination -37 ° 06 ′ 14 ″
Apparent brightness 1.62 (1.59 to 1.65) mag
Typing
B − V color index (−0.14) 
U − B color index (−0.96) 
Spectral class B1.5 IV / PMS / B2 IV
Variable star type BCEP + EA 
Astrometry
Radial velocity (−3.0 ± 2.8) km / s
parallax (5.71 ± 0.75)  mas
distance (600)  ly
Proper movement 
Rec. Share: (−8.53 ± 1.08)  mas / a
Dec. portion: (−30.80 ± 0.62)  mas / a
Physical Properties
Dimensions (14.5 / 2 / 10.6)  M ☉
radius (9 / 1.5 / 5)  R ☉
Effective temperature (25000 /? / 25000)  K
Age <15 mill.  A
Other names
and catalog entries
Bayer name λ Scorpii
Flamsteed name 35 Scorpii
Cordoba Survey CD −37 11673
Bright Star Catalog HR 6527 [1]
Henry Draper Catalog HD 158926 [2]
Hipparcos catalog HIP 85927 [3]
SAO catalog SAO 208954 [4]
Tycho catalog TYC 7388-1093-1 [5]
2MASS catalog 2MASS J17333652-3706135 [6]
Other names Shaula, Alascha, FK5 652

Lambda Scorpii (also Shaula , or Alascha ) is a multiple star system in the constellation Scorpio . Lambda Scorpii is located on the sting of the scorpion, the name ( Arabic الشولاء, DMG aš-šaulāʾ ) means "raised tail". The system has an apparent magnitude of +1.62 mag, making it one of the 50 brightest stars in the night sky. It is about 600 light years away ( Hipparcos database) and a member of the Gouldian Belt .

system

The star system of Lambda Scorpii consists of at least 3 components. The brightest component Lambda Scorpii Aa was named Shaula by the IAU in 2016 . It is a massive Beta Cephei star . There are also 2 other components in the system. Lambda Scorpii Ab orbits Lambda Scorpii Aa in a narrow orbit with an orbital time of only about 6 days. It is significantly less massive than the other two components. Its nature is unknown: either it is in a very early phase (pre- main sequence phase or at the beginning of the main sequence ) or it is a relatively massive compact star . Together, the two form a cover-variable algolstern . Lambda Scorpii B is significantly further away and orbits Lambda Scorpii Aa with a period of about 3 years.

See also

Individual evidence

  1. ↑ a b c d e f lam Sco. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed January 27, 2020 .
  2. ^ Hipparcos catalog (ESA 1997)
  3. ↑ a b c lam Sco. In: VSX. AAVSO , accessed January 27, 2020 .
  4. ↑ a b c d G. Handler, A. Schwarzenberg-Czerny: Time-resolved multicolour photometry of bright B-type variable stars in Scorpius . In: Astronomy & Astrophysics . 557, 2013, p. A1. arxiv : 1307.2733 . bibcode : 2013A & A ... 557A ... 1H . doi : 10.1051 / 0004-6361 / 201321886 .
  5. ↑ a b c d Shaula. In: STARS. Jim Kaler, accessed January 27, 2020 .
  6. ^ IAU Catalog of Star Names (IAU-CSN). International Astronomical Union , accessed January 27, 2020 .