Astronomy:Kappa Capricorni
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| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Capricornus |
| Right ascension | 21h 42m 39.508s[1] |
| Declination | −18° 51′ 58.76″[1] |
| Apparent magnitude (V) | +4.73[2] |
| Characteristics | |
| Evolutionary stage | red clump[3] |
| Spectral type | G8 III[4] |
| U−B color index | +0.51[2] |
| B−V color index | +0.88[2] |
| Astrometry | |
| Radial velocity (Rv) | −2.87±0.18[5] km/s |
| Proper motion (μ) | RA: +146.354[1] mas/yr Dec.: −8.343[1] mas/yr |
| Parallax (π) | 10.6991 ± 0.1277[1] mas |
| Distance | 305 ± 4 ly (93 ± 1 pc) |
| Absolute magnitude (MV) | −0.023[6] |
| Details[7] | |
| Mass | 2.43±0.21 M☉ |
| Radius | 13.28±0.47 R☉ |
| Luminosity | 106.8±5.9 L☉ |
| Surface gravity (log g) | 2.59±0.06 cgs |
| Temperature | 5,096±57 K |
| Metallicity [Fe/H] | −0.39±0.10 dex |
| Rotational velocity (v sin i) | 0.0[5] km/s |
| Age | 1.19[8] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Kappa Capricorni is a solitary[10] star in the constellation Capricornus. Its name is a Bayer designation that is Latinized from κ Capricorni, and abbreviated Kappa Cap or κ Capricorni. This star is visible to the naked eye with an apparent visual magnitude of +4.73.[2] Based upon an annual parallax shift of 11.09 mas as seen from the Earth,[1] the star is located about 305 light-years (93 pc) from the Sun. It is drifting closer with a line of sight velocity of −3 km/s.[5] The star is positioned sufficiently close to the ecliptic that it is occasionally subject to lunar occultation.[11]
This is a yellow-hued, evolved, G-type giant star with a stellar classification of G8 III.[4] There is a 91% probability that it is currently on the horizontal branch, rather than the red giant branch.[7] As such, it is a red clump[3] giant with an estimated 2.43 times the mass of the Sun and has expanded to 13.28 times the radius of the Sun.[7] The star is about 1.2[8] billion years old and has a projected rotational velocity that is too small to be measured.[5] It radiates 107 times the solar luminosity from its photosphere at an effective temperature of 5,096 K.[7]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940. Gaia DR3 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99): 99, Bibcode: 1966CoLPL...4...99J.
- ↑ 3.0 3.1 Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode: 2000ApJ...539..732A.
- ↑ 4.0 4.1 Houk, N.; Smith-Moore, M. (1988), Michigan Catalogue of Two-dimensional Spectral Types for the HD Stars, 4, Bibcode: 1988mcts.book.....H.
- ↑ 5.0 5.1 5.2 5.3 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, doi:10.1088/0004-6256/135/1/209, Bibcode: 2008AJ....135..209M.
- ↑ Soubiran, C. et al. (2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants", Astronomy and Astrophysics 480 (1): 91–101, doi:10.1051/0004-6361:20078788, Bibcode: 2008A&A...480...91S.
- ↑ 7.0 7.1 7.2 7.3 Reffert, Sabine et al. (2015), "Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity", Astronomy and Astrophysics 574A (2): 116–129, doi:10.1051/0004-6361/201322360, Bibcode: 2015A&A...574A.116R. Values are based on 91% probability it is on the horizontal branch.
- ↑ 8.0 8.1 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", The Astronomical Journal 150 (3): 88, doi:10.1088/0004-6256/150/3/88, Bibcode: 2015AJ....150...88L.
- ↑ "kap Cap". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=kap+Cap.
- ↑ Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Evans, D. S. et al. (November 1985), "Photoelectric observations of lunar occultations. XV.", Astronomical Journal 90: 2360–2371, doi:10.1086/113941, Bibcode: 1985AJ.....90.2360E.
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