Kappa Virginis
 | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Virgo |
| Right ascension | 14h 12m 53.74538s[1] |
| Declination | −10° 16′ 25.3340″[1] |
| Apparent magnitude (V) | 4.180[2] |
| Characteristics | |
| Spectral type | K2/3 III[3] |
| U−B color index | +1.457[2] |
| B−V color index | +1.343[2] |
| Astrometry | |
| Radial velocity (Rv) | −4.38±0.21[4] km/s |
| Proper motion (μ) | RA: +7.25[1] mas/yr Dec.: +139.88[1] mas/yr |
| Parallax (π) | 12.80 ± 0.25 mas[1] |
| Distance | 255 ± 5 ly (78 ± 2 pc) |
| Details | |
| Mass | 1.46±0.04[5] M☉ |
| Radius | 25.41±0.74[5] R☉ |
| Luminosity | 229[5] L☉ |
| Surface gravity (log g) | 1.83±0.08[5] cgs |
| Temperature | 4235±20[5] K |
| Metallicity [Fe/H] | −0.43±0.04[5] dex |
| Rotational velocity (v sin i) | 5.1[4] km/s |
| Age | 9.67±0.97[5] Gyr |
| Other designations | |
Kappa Virginis (κ Vir, κ Virginis) is a solitary star in the zodiac constellation of Virgo. It has an apparent visual magnitude of 4.18,[2] which is sufficiently bright to be seen with the naked eye. Based upon stellar parallax measurements, the distance to this star is about 255 light years.
This is an orange-hued K-type giant star with a stellar classification of K2/3 III.[3] It has about 146% of the mass of the Sun, but at an estimated age of 9.7 billion years it has evolved and expanded to over 25 times the Sun's radius. As a consequence, it shines with around 229 times the solar luminosity. The effective temperature of the star's outer atmosphere is 4,235 K.[5]
References
- ^ a b c d e van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
- ^ a b c d Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants.", Monthly Notices of the Royal Astronomical Society, 172: 667–679, Bibcode:1975MNRAS.172..667J, doi:10.1093/mnras/172.3.667.
- ^ a b Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
- ^ a b Massarotti, Alessandro; et al. (January 2008), "Rotational and radial velocities for a sample of 761 HIPPARCOS giants and the role of binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209.
- ^ a b c d e f g h Maldonado, J.; et al. (June 2013), "The metallicity signature of evolved stars with planets", Astronomy & Astrophysics, 554: 18, arXiv:1303.3418, Bibcode:2013A&A...554A..84M, doi:10.1051/0004-6361/201321082, A84.
- ^ "kap Vir -- Variable Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-09-08.
 | This giant-star-related article is a stub. You can help Wikipedia by expanding it. |