Theta2 Tauri

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Double star
Theta2 Tauri
The Hyades with θ2 Tauri in the middle
The Hyades with θ 2 Tauri in the middle
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation bull
Right ascension 04 h 28 m 39.75 s
declination + 15 ° 52 ′ 15.1 ″
Apparent brightness 3.41 (3.35 to 3.42) mag
Typing
B − V color index +0.19 
U − B color index +0.09 
Spectral class A7 III
Variable star type DSCTC + E 
Astrometry
Radial velocity (38.9 ± 0.2) km / s
parallax (20.83 ± 0.37)  mas
distance (157 ± 3)  ly
(48)  pc
Proper movement 
Rec. Share: (103.33 ± 0.75)  mas / a
Dec. portion: (−18.63 ± 0.57)  mas / a
Physical Properties
Dimensions (2.42 ± 0.30 / 2.11 ± 0.17)  M ☉
Luminosity

(77)  L ☉

Metallicity [Fe / H] (+0.01)
Other names
and catalog entries
Bayer name θ 2 Tauri
Flamsteed name 78 Tauri
Bonn survey BD + 15 ° 632
Bright Star Catalog HR 1412 [1]
Henry Draper Catalog HD 28319 [2]
Hipparcos catalog HIP 20894 [3]
SAO catalog SAO 93957 [4]
Tycho catalog TYC 1265-1172-1 [5]
2MASS catalog 2MASS J04283971 + 1552151 [6]
Other names Chamukuy

θ 2 Tauri ( Theta2 Tauri or Chamukuy ) is a star system 157 light years away in the constellation Taurus and is part of the Hyades . The star is a component of the visual binary star Theta Tauri . Since the two components θ 1 Tauri and θ 2 Tauri are about 3 light years apart, they are not considered to be a gravitationally bound system, although the question has not yet been finally clarified. Theta Tauri itself acts as an eye checker , i.e. H. the θ 1 tau and θ 2 tau can already be separated from each other with bare eyes .

properties

θ 2 Tauri itself is a spectroscopic binary star . The two stars (components a and b) orbit each other at a distance of about 0.88 AU and need about 140 days for one orbit. The system belongs to the eclipsed variable stars . The lighter component a also has the spectral class A7 III and belongs to the pulsating Delta Scuti stars . The apparent brightness fluctuates between 3.35 and 3.42 during a period of about 109 minutes.

Web links

Individual evidence

  1. ↑ a b c d e f g tet02 Tau. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on August 3, 2018 .
  2. ↑ a b c tet 2 Tau. In: VSX. AAVSO, accessed August 3, 2018 .
  3. ↑ a b Guillermo Torres, Robert P. Stefanik, David W. Latham: The Hyades Binaries θ 1 Tauri and θ 2 Tauri: The Distance to the Cluster and the Mass ‐ Luminosity Relation . In: The Astrophysical Journal . 485, 1997, p. 167. bibcode : 1997ApJ ... 485..167T . doi : 10.1086 / 304422 .
  4. ^ A b E. Anderson, Ch. Francis: XHIP: An extended hipparcos compilation . In: Astronomy Letters . 38, No. 5, 2012, p. 331. arxiv : 1108.4971 . bibcode : 2012AstL ... 38..331A . doi : 10.1134 / S1063773712050015 .
  5. ↑ a b XHIP in VizieR. Retrieved August 3, 2018 .