Kappa Cancri
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Cancer |
| Right ascension | 08h 20m 32.13630s[1] |
| Declination | +24° 01′ 20.3198″[1] |
| Apparent magnitude (V) | +5.233[2] |
| Characteristics | |
| Spectral type | B8 IIIp[3] |
| B−V color index | −0.113[2] |
| Variable type | α2 CVn[4] |
| Astrometry | |
| Proper motion (μ) | RA: −20.29[1] mas/yr Dec.: −18.81[1] mas/yr |
| Parallax (π) | 7.13 ± 0.38 mas[1] |
| Distance | 460 ± 20 ly (140 ± 7 pc) |
| Absolute magnitude (MV) | −0.82[5] |
| Orbit[6] | |
| Period (P) | 6.3933 d |
| Eccentricity (e) | 0.13 |
| Periastron epoch (T) | 2440001.95 JD |
| Argument of periastron (ω) (secondary) | 157° |
| Semi-amplitude (K1) (primary) | 67.4 km/s |
| Details[7] | |
| κ Cnc A | |
| Mass | 4.5 M☉ |
| Radius | 5.0 R☉ |
| Luminosity | 322[5] L☉ |
| Surface gravity (log g) | 3.7±0.1[2] cgs |
| Temperature | 12,800±200[2] K |
| Metallicity [Fe/H] | +0.51[5] dex |
| Rotational velocity (v sin i) | 6±2[2] km/s |
| κ Cnc B | |
| Mass | 2.1 M☉ |
| Radius | 2.4 R☉ |
| Surface gravity (log g) | 4.0 cgs |
| Temperature | 8,500 K |
| Rotational velocity (v sin i) | 40 km/s |
| Other designations | |
| Database references | |
| SIMBAD | data |
Kappa Cancri, Latinized from κ Cancri, is a blue-white hued binary star system in the zodiac constellation of Cancer. It is faintly visible to the naked eye with an apparent visual magnitude of +5.23.[2] The magnitude difference between the two stars is about 2.6.[9] Based upon an annual parallax shift of 7.13 mas as seen from the Earth,[1] the system is located roughly 460 light years from the Sun.
This is a single-lined spectroscopic binary[2] star system with an orbital period of 6.39 days and an eccentricity of 0.13.[6] The primary, component A, has a stellar classification of B8 IIIp,[3] suggesting it is a B-type giant star. It a mercury-manganese star, a type of chemically peculiar star showing large overabundances of those two elements in the outer atmosphere.[2] It is classified as an Alpha2 Canum Venaticorum type variable star and its brightness varies from magnitude +5.22 to +5.27 with a period of 5 days.[4]
The primary component has 4.5 times the mass of the Sun, 5 times the Sun's radius, and an effective temperature of 13,200 K. The secondary, component B, is a smaller star with 2.1 times the mass and 2.4 times the radius of the Sun, having an effective temperature of 8,500 K.[7]
References
- ^ a b c d e f 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 e f g h Maza, Natalia L.; et al. (December 2014), "A non-LTE spectral analysis of the 3He and 4He isotopes in the HgMn star κ Cancri", Astronomy & Astrophysics, 572: 7, arXiv:1412.2052, Bibcode:2014A&A...572A.112M, doi:10.1051/0004-6361/201425037, A112.
- ^ a b Levato, H. (1975), "Rotational velocities and spectral types for a sample of binary systems", Astronomy and Astrophysics, 19: 91, Bibcode:1975A&AS...19...91L.
- ^ a b Samus', N. N.; et al. (January 2017), "General catalogue of variable stars: Version GCVS 5.1", Astronomy Reports, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085.
- ^ a b c Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015.
- ^ a b Pourbaix, D.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy & Astrophysics, 424 (2): 727, arXiv:astro-ph/0406573, Bibcode:2004A&A...424..727P, doi:10.1051/0004-6361:20041213.
- ^ a b Ryabchikova, T. (April 1998), "Abundance analysis of SB2 binary stars with HgMn primaries", Contributions of the Astronomical Observatory Skalnate Pleso, 27 (3): 319–323, arXiv:astro-ph/9805063, Bibcode:1998CoSka..27..319R.
- ^ "kap Cnc". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-19.
- ^ Ryabchikova, T.; et al. (April 1998), "Discovery of the secondary star of the HgMn binary kappa CANCRI", Contributions of the Astronomical Observatory Skalnate Pleso, 27 (3): 258–260, arXiv:astro-ph/9805143, Bibcode:1998CoSka..27..258R.
