Alshat
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Star Alshat (ν Capricorni) |
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| ν 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 20 m 39.82 s | ||||||||||||||||||
| declination | -12 ° 45 ′ 32.7 ″ | ||||||||||||||||||
| Apparent brightness | 4.75 likes | ||||||||||||||||||
| Typing | |||||||||||||||||||
| B − V color index | −0.05 | ||||||||||||||||||
| U − B color index | −0.11 | ||||||||||||||||||
| R − I index | −0.06 | ||||||||||||||||||
| Spectral class | B9 IV | ||||||||||||||||||
| Astrometry | |||||||||||||||||||
| Radial velocity | (−1.00 ± 0.1) km / s | ||||||||||||||||||
| parallax | (12.88 ± 0.27) mas | ||||||||||||||||||
| distance | (253 ± 5) ly (77.6 ± 1.6) pc |
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| Proper movement | |||||||||||||||||||
| Rec. Share: | (14.74 ± 0.33) mas / a | ||||||||||||||||||
| Dec. portion: | (−14.32 ± 0.22) mas / a | ||||||||||||||||||
| Physical Properties | |||||||||||||||||||
| Dimensions | 2.7 M ☉ | ||||||||||||||||||
| radius | 2.9 R ☉ | ||||||||||||||||||
| Luminosity |
87 L ☉ |
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| Effective temperature | 10,000 K | ||||||||||||||||||
| Metallicity [Fe / H] | −0.15 | ||||||||||||||||||
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Other names and catalog entries |
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Alshat (from Arabic الشاة, DMG aš-šāt 'the sheep') is the proper name of the star Ny Capricorni (ν Cap) in the constellation Capricorn . Alshat has an apparent magnitude of 4.8 mag and is approximately 253 light years away.
Ny Capricorni is a blue and white subgiant about 2.7 times the mass, 3 times the diameter and 87 times the luminosity of the sun . Its surface temperature is around 10,000 K.
The proper name of the star "Alshat" is to be seen mythologically in connection with the proper name "Dabih" of the neighboring star Beta Capricorni , which means "(lucky star of) the slaughterer", to whom the sheep is symbolically taken for slaughter.
Scientific investigations
The light from the star was examined spectroscopically for the abundance of different elements. Peculiarities in the profiles of the spectral lines , similar to those observed in Wega and other stars, can possibly be explained by the fact that the star rotates rapidly, but its axis of rotation is approximately directed towards us, since the value of the projected equatorial rotation speed v ∙ sin i is only about 24 km / s.
Individual evidence
- ↑ a b c d e VizieR: Hipparcos, the New Reduction (van Leeuwen, 2007) - The Astrometric Catalog
- ↑ a b VizieR: Stellar Photometry in Johnson's 11-color system (Ducati, 2002) - Photometric data in the UBVRIJHKLMN colors
- ↑ VizieR: Michigan Catalog of HD stars, Vol.4 (Houk +, 1988) - The Catalog
- ^ VizieR: Pulkovo radial velocities for 35493 HIP stars (Gontcharov, 2006) - Main catalog data
- ↑ a b c VizieR: Fundamental parameters of stars (Allende Prieto +, 1999)
- ↑ a b VizieR: Extended Hipparcos Compilation (XHIP) (Anderson +, 2012)
- ↑ L. Ideler: Investigations into the origin and the meaning of the star names. Berlin 1809, pp. 191-193 PDF; 19.6 MB .
- ^ SJ Adelmann: Elemental abundance analyzes with DAO spectrograms. - VII. The late normal B stars Pi Ceti, 134 Tauri, 21 Aquilae, and Nu Capricorni and the use of Reticon spectra. In: Monthly Notices of the Royal Astronomical Society. Vol. 252, 1991, doi: 10.1093 / mnras / 252.1.116 , pp. 116-131, bibcode : 1991MNRAS.252..116A .
- ^ AF Gulliver, SJ Adelmann, Ch.R. Cowley, JM Fletcher: Metallic line profiles of the A0 V star Vega. In: The Astrophysical Journal. Vol. 380, 1991, doi: 10.1086 / 170577 , pp. 223-229, bibcode : 1991ApJ ... 380..223G .
- ^ VizieR: Rotational velocities of A-type stars. IV. (Zorec +, 2012)