Menkar (α Kita, Alpha Kita) is a red giant in the constellation Kita, spectral class M1.5 IIIa. The name comes from the Arabic word منخر ( manħar , "nostril" ). In Chinese astronomy, it was designated as the first star of the configuration of Tien-jun ( "Heavenly bins" ) - 天 囷 一 ( Chinese ) [2] .
| Menkar | |||
|---|---|---|---|
| Star | |||
  | |||
| Observational data ( Age j2000 ) | |||
| Right ascension | 03 h 02 m 16.77307 s | ||
| Declination | + 04 ° 05 ′ 23.0596 ″ | ||
| Distance | 249 ± 8 St. years (76 ± 3 pc ) | ||
| Visible magnitude ( V ) | +2.53 | ||
| Constellation | Whale | ||
| Astrometry | |||
| Radial velocity ( R v ) | –26.08 ± 0.02 km / s | ||
| Own movement (μ) | RA: -10.41 ± 0.51 mas per year Dec: -76.85 ± 0.36 mas per year | ||
| Parallax (π) | 13.09 ± 0.44 mas | ||
| Absolute magnitude (V) | –3.2 ± 0.3 | ||
| Characteristics | |||
| Spectral class | M1.5 IIIa | ||
| Color Index ( B - V ) | +1.64 | ||
| Color Index ( U - B ) | +1.93 | ||
| Variability | |||
| physical characteristics | |||
| Weight | 2.3 ± 0.2 M ☉ | ||
| Radius | 89 ± 5 R ☉ | ||
| Temperature | 3795 ± 70 K | ||
| Luminosity | 1455 ± 328 L ☉ | ||
| Metallicity | 0.00 ± 0.30 | ||
| Rotation | 6.9 | ||
| |||
| Database Information | |||
| SIMBAD | |||
Despite the fact that according to the Bayer catalog, the star is designated as α Ceti, it is not the brightest star in the constellation (the apparent magnitude of α Ceti is 2.53, β of Ceti is 2.04). The mass of the star is more than twice the mass of the Sun, while its radius is 89 times greater than the solar. Due to the large area of the photosphere, a star radiates 1455 times more energy than the Sun, although its effective temperature is only 3795 K (5778 K for the Sun). Relatively low temperature gives the star a red tint typical of M-class stars [3] .
A star came off the main sequence after burning out helium in its core. With the beginning of the burning of the carbon core, the star is likely to become extremely unstable, similar to the World , and, dropping the outer layers, will form a planetary nebula , remaining a relatively large white dwarf [4] .
The Alpha Kit planetary system is set in the 22nd episode of Star Trek , the 311st episode of South Park, and the 8th episode of the third season of Star Trek: Enterprise .
Notes
- ↑ 1 2 3 4 Leeuwen F. v. Validation of the new Hipparcos reduction // Astron. Astrophys. - EDP Sciences , 2007. - Vol. 474, Iss. 2. - P. 653–664. - ISSN 0004-6361 ; 0365-0138 ; 1432-0746 ; 1286-4846 - doi: 10.1051 / 0004-6361: 20078357 - arXiv: 0708.1752
- ↑ Annotated Index of Astronomical Terms
- ↑ The Color of Stars , Commonwealth Scientific and Industrial Research Organization, December 21, 2004 , < http://outreach.atnf.csiro.au/education/s Senior / astrophysics / photometry_colour.html > . Retrieved January 16, 2012. Archived March 10, 2012.
- ↑ Kaler, James B., MENKAR (Alpha Ceti) , University of Illinois , < http://stars.astro.illinois.edu/sow/menkar.html > . Retrieved December 24, 2011.