Capella (star)

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Double star
Capella (α Aur)
Capella in the constellation Carter
Observation
dates equinox :  J2000.0 , epoch : J2000.0
AladinLite
Constellation Carter
Apparent brightness  0.08 (0.03 to 0.16) mag
Astrometry
Radial velocity 29.2 ± 0.07 km / s
parallax 76.2 ± 0.46 mas
distance  42.8 ± 0.3 ly
(13.1 ± 0.1 pc )
Proper movement :
Rec. Share: 75.25 ± 0.54 mas / a
Dec. portion: −426.89 ± 0.28 mas / a
Individual data
Names A; H / L
Observation data:
Right ascension A. 5 h 16 m 41.40 s
H / L 517245 h 17 m 24 s
declination A. 2455953+ 45 ° 59 ′ 53.0 ″
H / L 2455020+ 45 ° 50 ′ 20 ″
Apparent brightness A. 0.76 / 0.91 mag
H / L 10.16 / 13.7 mag
Typing:
Spectral class A. G8 III / G0 III
H / L M1 / M5
B − V color index A. 0.8
H / L 1.5
U − B color index A. 0.45
H / L 1.24
Physical Properties:
Dimensions A. 2.6 / 2.5 M ☉
H / L 0.57 / 0.53 M ☉
radius A. 12 / 8.8 R ☉
H / L 0.56 / 0.25 R ☉
Luminosity A. 78.7 / 72.7 L ☉
H / L 0.012 / 0.00048 L ☉
Effective temperature A. 4970/5730 K
H / L
Metallicity [Fe / H] A. −0.04
H / L
Other names
and catalog entries
Bayer name α Aurigae
Flamsteed name 13 Aurigae
Bright Star Catalog HR 1708 [1]
Henry Draper Catalog HD 34029 [2]
SAO catalog SAO 40186 [3]
Tycho catalog TYC 3358-3141-1 [4]
Hipparcos catalog HIP 24608 [5]
Further designations: GL 194, GJ 194 (Capella Aa-Ab), FK5 193
  GL 195, GJ 195 (Capella HL)
  1. ↑ Data for Capella Aa, Ab
  2. ↑ Data for Capella H, L

Template: Infobox double star / maintenance / single coordinates

Capella (Latin for "little goat") or Kapella is the main star (α Aurigae) in the constellation Fuhrmann . The name goes back to the Latin diminutive of the word capra (female goat) , kid. The Greek mythology describes the Greek god Zeus goat Amalthea was nurtured as he grew up in Crete. As a thank you, he moved it to the starry sky. Capella is also called Alhajoth , which is probably an Arabicized form of the Greek word αίξ (goat).

General

Capella is the brightest star in the Auriga constellation.

Capella is 0.1 like the sechsthellste star in the night sky and after Arcturus and Vega the third brightest in the northern sky . Capella forms the northern tip of the winter hexagon .

Capella is a double-double star system , consisting of the components Aa and Ab as well as H and L. Capella Aa and Ab circle around the common center of gravity on almost perfect circular orbits at intervals of 0.74 AU within 104 days.

The two binary star systems Aa-Ab and HL (under single data binary star systems A and H / L) have an average projected distance of approx. 9,500 AU to each other. While the components Aa ( spectral class G8 III) and Ab (spectral class G0 III) belong to the so-called yellow giants , H (spectral class M1) and L (spectral class M5) are red dwarfs , which are located at a distance of almost 49 AU and a period of about 300 years.

It is a physically bound, hierarchical quadruple system.

At a distance of a good 43 light years , the two main stars belong to the giant stars relatively close to Earth. Due to the intrinsic movement of the system, Capella belongs to the Hyaden Stream (see also stellar currents ), a widely distributed group of stars whose physical connection is still unclear.

Size comparison between the sun and the components of the Capella star system
Adaptive optics Image of Capella H (1) and L (2) in the near infrared with the Hale telescope

Web links

Commons : Capella  - collection of images, videos and audio files

Individual evidence

  1. ↑ a b c d e f g alf Aur. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on August 2, 2019 .
  2. ^ NSV 1897. In: VSX. AAVSO , accessed August 2, 2019 .
  3. ↑ Capella. Jim Kaler, accessed August 2, 2019 .
  4. ↑ a b c d K.G. Helminiak, M. Konacki, SR Kulkarni, J. Eisner: Precision astrometry of a sample of speckle binaries and multiples with the adaptive optics facilities at the Hale and Keck II telescopes . In: MNRAS . 400, 2009, p. 16. arxiv : 0908.3468 . bibcode : 2009MNRAS.400..406H . doi : 10.1111 / j.1365-2966.2009.15495.x .
  5. ↑ a b c d e f g h Guillermo Torres, Antonio Claret, Krešimir Pavlovski, Aaron Dotter: Capella (α Aurigae) Revisited: New Binary Orbit, Physical Properties, and Evolutionary State . In: The Astrophysical Journal . 807, 2015, p. 26. arxiv : 1505.07461 . bibcode : 2015ApJ ... 807 ... 26T . doi : 10.1088 / 0004-637X / 807/1/26 .
  6. ↑ B. Famaey, F. Pont, X. Luri, S. Udry, M. Mayor, A. Jorissen: The Hyades stream: an evaporated cluster or an intrusion from the inner disk? . In: Astronomy & Astrophysics . 461, No. 3, 01/2007, pp. 957-962. arxiv : astro-ph / 0609785 . bibcode : 2007A & A ... 461..957F . doi : 10.1051 / 0004-6361: 20065706 .