Lambda Tauri

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Multiple star
λ Tauri
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation bull
Right ascension 04 h 00 m 40.82 s
declination + 12 ° 29 ′ 25.3 ″
Apparent brightness 3.41 (3.37 to 3.91) mag
Typing
B − V color index (−0.12) 
U − B color index (−0.63) 
R − I index (−0.09) 
Spectral class B3 V + A4 IV + G / K
Variable star type EA / DM 
Astrometry
Radial velocity (17.8 ± 0.9) km / s
parallax (8.21 ± 0.53)  mas
distance (400 ± 25)  ly
(120)  pc
Proper movement 
Rec. Share: (−7.9 ± 1.2)  mas / a
Dec. portion: (−14.6 ± 0.9)  mas / a
Physical Properties
Dimensions (7.18 / 1.89 / 0.7)  M ☉
radius (6.40 / 5.30)  R ☉
Luminosity

( 4000/95 )  L ☉

Age 100 mill.  A
Other names
and catalog entries
Bayer name λ Tauri
Flamsteed name 35 Tauri
Bonn survey BD + 12 ° 539
Bright Star Catalog HR 1239 [1]
Henry Draper Catalog HD 25204 [2]
Hipparcos catalog HIP 18724 [3]
SAO catalog SAO 93719 [4]
Tycho catalog TYC 662-1546-1 [5]
2MASS catalog 2MASS J04004082 + 1229253 [6]
Other names FK5  150

Lambda Tauri ( λ Tauri , λ Tau ) is a star system in the constellation Taurus . It has an apparent magnitude of around 3.4 mag and is around 400 light years away. The system is probably a triple star .

properties

As early as 1848 it was discovered that the star is a variable star . The inner pair Lambda Tauri AB orbits each other with a period of 3.95 days at a distance of about 22 R ☉ from each other. The third star is probably a star of the spectral class G or K and is responsible for a second observed period of about 33 days, which can be seen in the light curves .

Individual evidence

  1. ↑ a b c d e f g h lam Tau. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed August 25, 2018 .
  2. ↑ a b c Lam Tau. In: VSX. AAVSO, accessed August 25, 2018 .
  3. ↑ a b c d F. C., Jr. Fekel, J. Tomkin: Secondaries of eclipsing binaries. IV - The triple system Lambda Tauri . In: Astrophysical Journal, Part 1 . 263, December 1982, pp. 289-301. bibcode : 1982ApJ ... 263..289F . doi : 10.1086 / 160503 .
  4. ^ A b A. Dervişoğlu, Christopher A. Tout, C. Ibanoğlu: Spin angular momentum evolution of the long-period Algols . In: Monthly Notices of the Royal Astronomical Society . 406, No. 2, August 2010, pp. 1071-1083. arxiv : 1003.4392 . bibcode : 2010MNRAS.406.1071D . doi : 10.1111 / j.1365-2966.2010.16732.x .
  5. ↑ a b Lambda Tau. Jim Kaler, accessed August 25, 2018 .
  6. ↑ David Vesper, Kent Honeycutt, Thomas Hunt: Survey of Hα Mass Transfer Structures in Classical Algol-Type Binaries . In: The Astronomical Journal . 121, No. 5, May 2001, pp. 2723-2736. bibcode : 2001AJ .... 121.2723V . doi : 10.1086 / 320381 .