Ain (star)
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Star ε Tauri / Ain |
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| AladinLite | |||||||||||||||||||||
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | bull | ||||||||||||||||||||
| Right ascension | 04 h 28 m 37 s | ||||||||||||||||||||
| declination | + 19 ° 10 ′ 49.6 ″ | ||||||||||||||||||||
| Apparent brightness | (3.53 ± 0.05) mag | ||||||||||||||||||||
| Typing | |||||||||||||||||||||
| Known exoplanets | 1 | ||||||||||||||||||||
| B − V color index | 1.01 | ||||||||||||||||||||
| U − B color index | 0.88 | ||||||||||||||||||||
| R − I index | 0.50 | ||||||||||||||||||||
| Spectral class | K0 III | ||||||||||||||||||||
| Astrometry | |||||||||||||||||||||
| Radial velocity | (38.5 ± 0.05) km / s | ||||||||||||||||||||
| parallax | (20.31 ± 0.83) mas | ||||||||||||||||||||
| distance | (160 ± 3) ly (49.2 ± 1.0) pc |
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| Visual absolute brightness M vis | (0.145) mag | ||||||||||||||||||||
| Proper movement | |||||||||||||||||||||
| Rec. Share: | (107.50 ± 1.04) mas / a | ||||||||||||||||||||
| Dec. portion: | (−38.07 ± 0.70) mas / a | ||||||||||||||||||||
| Physical Properties | |||||||||||||||||||||
| Dimensions | (2.7 ± 0.1) M ☉ | ||||||||||||||||||||
| radius | (12.7 ± 0.6) R ☉ | ||||||||||||||||||||
| Luminosity |
(97 ± 8) L ☉ |
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| Effective temperature | (4901 ± 20) K. | ||||||||||||||||||||
| Metallicity [Fe / H] | (0.17 ± 0.04) | ||||||||||||||||||||
| Age | ≈ 625 · 10 6 a | ||||||||||||||||||||
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Other names and catalog entries |
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Ain is the name of the star ε Tauri (Epsilon Tauri) in the constellation Taurus . The name comes from Arabic عين, DMG ʿAin 'eye', or Latin Oculus Borealis , "eye of the bull". Another name is Koronis ( ancient Greek Κορωνις ), one of the Hyades .
Ain belongs to the spectral class G9 and has an apparent brightness of +3.5 mag. It is about 160 light years away and part of the Hyades open cluster . The star is in a late stage of development and is currently a Red Clump Star . The star has an 11th magnitude companion at a distance of 182 arc seconds , corresponding to about 8600 AU . The orbital period of this companion is given as around 500,000 years, if it is tied to Ain at all.
As a star close to the ecliptic, Ain can be covered by the moon and rarely also by planets .
In 2007, an exoplanet was observed, named Amateru in 2015, orbiting Ain at a distance of about 1.9 AU with a period of 1.6 years.
Web links
Individual evidence
- ↑ a b c d e f eps tau. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed August 18, 2018 .
- ↑ a b c Bright Star Catalog
- ↑ a b c d e Bun'ei Sato, Hideyuki Izumiura, Eri Toyota, Eiji Kambe, Yoichi Takeda, Seiji Masuda, Masashi Omiya, Daisuke Murata, Yoichi Itoh: A Planetary Companion to the Hyades Giant ε Tauri . In: The Astrophysical Journal . 661, No. 1, 2007, pp. 527-531. bibcode : 2007ApJ ... 661..527S . doi : 10.1086 / 513503 .
- ↑ Erika Böhm-Vitense, Kenneth G. Carpenter, Richard D. Robinson: Ultraviolet Emission Lines in BA and Non-BA Giants . In: The Astrophysical Journal . 545, No. 2, December 2000, pp. 992-999. bibcode : 2000ApJ ... 545..992B . doi : 10.1086 / 317850 .
- ↑ Gerard T. van Belle and Kaspar von Braun: Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars . (abstract) In: The Astrophysical Journal . 694, No. 2, 2009, pp. 1085-1098. arxiv : 0901.1206 . bibcode : 2009ApJ ... 694.1085V . doi : 10.1088 / 0004-637X / 694/2/1085 .
- ↑ a b eps tau. In: Extrasolar Planets Encyclopaedia . Retrieved August 18, 2018 .
- ↑ AIN. Jim Kaler, accessed August 18, 2018 .