Prokyon
Double star Prokyon (α Canis Minoris) |
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Location of the star in the constellation Little Dog | ||||||||||||||||||||||||||
Observation dates equinox : J2000.0 , epoch : J2000.0 |
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AladinLite | ||||||||||||||||||||||||||
Constellation | Small dog | |||||||||||||||||||||||||
Right ascension | 07 h 39 m 18.1 s | |||||||||||||||||||||||||
declination | + 05 ° 13 ′ 30.0 ″ | |||||||||||||||||||||||||
Apparent brightness | 0.37 mag | |||||||||||||||||||||||||
Astrometry | ||||||||||||||||||||||||||
Radial velocity | (−3.2 ± 0.9) km / s | |||||||||||||||||||||||||
parallax | (285.9 ± 0.9) mas | |||||||||||||||||||||||||
distance | (11.41 ± 0.04) Lj ((3.497 ± 0.011) pc ) |
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Proper movement : | ||||||||||||||||||||||||||
Rec. Share: | approx. −717 mas / a | |||||||||||||||||||||||||
Dec. portion: | approx. −1035 mas / a | |||||||||||||||||||||||||
Individual data | ||||||||||||||||||||||||||
Names | A; B. | |||||||||||||||||||||||||
Observation data: | ||||||||||||||||||||||||||
Apparent brightness | A. | +0.37 mag | ||||||||||||||||||||||||
B. | 10.92 mag | |||||||||||||||||||||||||
Typing: | ||||||||||||||||||||||||||
Spectral class | A. | F5 IV-V | ||||||||||||||||||||||||
B. | DQZ | |||||||||||||||||||||||||
B − V color index | A. | (+0.42) | ||||||||||||||||||||||||
B. | (−0.22) | |||||||||||||||||||||||||
U − B color index | A. | (+0.03) | ||||||||||||||||||||||||
Physical Properties: | ||||||||||||||||||||||||||
Absolute vis. Brightness M vis |
A. | +2.7 mag | ||||||||||||||||||||||||
B. | +13 likes | |||||||||||||||||||||||||
Dimensions | A. | 1.5 M ☉ | ||||||||||||||||||||||||
B. | 0.6 M ☉ | |||||||||||||||||||||||||
radius | A. | 2.05 R ☉ | ||||||||||||||||||||||||
B. | 0.012 R ☉ | |||||||||||||||||||||||||
Luminosity | A. | 6.93 L ☉ | ||||||||||||||||||||||||
B. | 0.0005 L ☉ | |||||||||||||||||||||||||
Effective temperature | A. | 6530 K | ||||||||||||||||||||||||
B. | 7740 K | |||||||||||||||||||||||||
Rotation time | A. | 4.6 d | ||||||||||||||||||||||||
B. | 0.5 d | |||||||||||||||||||||||||
Age | 1.7 billion years | |||||||||||||||||||||||||
Other names and catalog entries |
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Prokyon [proˈkyɔn] (α Canis Minoris; synonyms: Elgomaisa, Algomeysa, Antecanis ; in ancient Egyptian Imi-chet-Sopdet ) is the brightest star in the constellation Little Dog . At a distance of 11.4 light years , it is one of the stars closest to the Sun. The Greek name means "before the dog" and indicates that it rises before Sirius , the dog star.
description
Prokyon is part of the winter hexagon and winter triangle .
Like Sirius, Prokyon is a double star - the main star Prokyon A, a whitish-yellow star of the spectral class F5, has a faint companion 11th magnitude, Prokyon B, which is a white dwarf . The orbital period of the binary star system is 41 years.
Measurements by the MOST satellite could not detect any oscillations (fluctuations in brightness) at Prokyon. These should be measurable in so-called starquakes, which were expected at Prokyon (→ helioseismology ).
Others
Prokyon is depicted in the flag of Brazil , where it represents the state of Amazonas .
Web links
Individual evidence
- ↑ a b c d e f alf CMi. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed September 18, 2018 .
- ↑ a b alf CMi B. In: SIMBAD. Center de Données astronomiques de Strasbourg, accessed September 18, 2018 .
- ^ Hipparcos catalog (1997)
- ^ Daniel J. Schroeder, David A. Golimowski, Ryan A. Brukardt, Christopher J. Burrows, John J. Caldwell, William G. Fastie, Holland C. Ford, Brigette Hesman, Ilona Kletskin, John E. Krist, Patricia Royle, Richard. A. Zubrowski: A Search for Faint Companions to Nearby Stars Using the Wide Field Planetary Camera 2 . In: The Astronomical Journal . 119, No. 2, February 2000, pp. 906-922. bibcode : 2000AJ .... 119..906S . doi : 10.1086 / 301227 .
- ↑ James Liebert, Gilles Fontaine, Patrick A. Young, Kurtis A. Williams, David Arnett: The Age and Stellar Parameters of the Procyon Binary System . In: The Astrophysical Journal . 769, No. 1, May 2013, p. 10. arxiv : 1305.0587 . 7. bibcode : 2013ApJ ... 769 .... 7L . doi : 10.1088 / 0004-637X / 769/1/7 .
- ↑ a b c J. L. Provencal, HL Shipman, Detlev Koester, F. Wesemael, P. Bergeron: Procyon B: Outside the Iron Box . In: The Astrophysical Journal . 568, No. 1, 2002, pp. 324-334. bibcode : 2002ApJ ... 568..324P . doi : 10.1086 / 338769 .
- ↑ a b c P. Kervella, F. Thévenin, P. Morel, G. Berthomieu, P. Bordé, J. Provost: The diameter and evolutionary state of Procyon A. Multi-technique modeling using asteroseismic and interferometric constraints . In: Astronomy and Astrophysics . 413, No. 1, January 2004, pp. 251-256. arxiv : astro-ph / 0309148 . bibcode : 2004A & A ... 413..251K . doi : 10.1051 / 0004-6361: 20031527 .
- ↑ N. Giammichele, P. Bergeron, P. Dufour: Know Your Neighborhood: A Detailed Model Atmosphere Analysis of Nearby White Dwarfs . In: The Astrophysical Journal Supplement . 199, No. 2, April 2012, p. 29. arxiv : 1202.5581 . bibcode : 2012ApJS..199 ... 29G . doi : 10.1088 / 0067-0049 / 199/2/29 . Age is for the white dwarf stage.