Omega Capricorni
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Star ω Capricorni |
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| ω cap in the constellation "Capricorn" | |||||||||||||||||||||
| AladinLite | |||||||||||||||||||||
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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| Constellation | Capricorn | ||||||||||||||||||||
| Right ascension | 20 h 51 m 49.29 s | ||||||||||||||||||||
| declination | -26 ° 55 ′ 8.9 ″ | ||||||||||||||||||||
| Apparent brightness | 4.22 likes | ||||||||||||||||||||
| Typing | |||||||||||||||||||||
| B − V color index | 1.63 | ||||||||||||||||||||
| U − B color index | 1.91 | ||||||||||||||||||||
| R − I index | 0.94 | ||||||||||||||||||||
| Spectral class | K4 III | ||||||||||||||||||||
| Astrometry | |||||||||||||||||||||
| Radial velocity | (9.1 ± 1.4) km / s | ||||||||||||||||||||
| parallax | (3.87 ± 0.68) mas | ||||||||||||||||||||
| distance | (840 ± 150) ly (258 ± 45) pc |
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| Proper movement | |||||||||||||||||||||
| Rec. Share: | (−8.36 ± 0.78) mas / a | ||||||||||||||||||||
| Dec. portion: | (−0.36 ± 0.64) mas / a | ||||||||||||||||||||
| Physical Properties | |||||||||||||||||||||
| Effective temperature | 4150 K | ||||||||||||||||||||
| Metallicity [Fe / H] | −0.30 | ||||||||||||||||||||
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Other names and catalog entries |
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Omega Capricorni (ω Cap) is a star in the constellation Capricorn . It has an apparent magnitude of 4.2 mag and its distance is approximately 840 light years .
The star is a red giant star with 48 times the diameter, 7 times the mass and 3800 times the luminosity of the sun .
Omega Capricorni is occasionally referred to as “Baten al-Giedi” (from Arabic بطن الجدي, DMG baṭn al-ǧady 'belly of the billy goat').
Scientific research
Omega Capricorni belongs to the rare group of barium stars among the red giants, which show unusually strong lines of simply ionized barium and other elements in their emission spectrum . Almost all barium stars are components of a binary system where they are orbited by a white dwarf that cannot be directly observed. This is likely the case with Omega Capricorni as well. In a study from 1991, the star was classified in the Ba 0.5 class, making it one of the weak barium stars.
Individual evidence
- ^ A b c VizieR: Hipparcos, the New Reduction (van Leeuwen, 2007) - The Astrometric Catalog
- ↑ a b c VizieR: Stellar Photometry in Johnson's 11-color system (Ducati, 2002)
- ^ VizieR: Rotation and Spectral Peculiarities (Abt + 1995)
- ↑ VizieR: Pulkovo radial velocities for 35493 HIP stars (Gontcharov, 2006)
- ↑ VizieR: JMMC Stellar Diameters Catalog - JSDC (Lafrasse +, 2010)
- ↑ VizieR: Extended Hipparcos Compilation (XHIP) (Anderson +, 2012)
- ^ VizieR: Catalog of Stellar Diameters (CADARS) (Pasinetti-Fracassini + 2001)
- ↑ VizieR: Young runaway stars within 3 kpc (Tetzlaff +, 2011)
- ↑ VizieR: Infrared excesses of Hipparcos stars (McDonald +, 2012)
- ↑ Ph. K. Lu: Taxonomy of Barium Stars. In: The Astronomical Journal. Vol. 101, 1991, doi: 10.1086 / 115845 , pp. 2229-2254 ( bibcode : 1991AJ .... 101.2229L ).