25 Canum Venaticorum is a binary star[10] system in the northern constellation of Canes Venatici, approximately 199[1] light years from the Sun. It is visible to the naked eye as a faint, white-hued star with a combined apparent visual magnitude of +4.82[2] The system is moving closer to the Earth with a heliocentric radial velocity of roughly −10 km/s.[2]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Canes Venatici |
| Right ascension | 13h 37m 27.62782s[1] |
| Declination | +36° 17′ 41.6337″[1] |
| Apparent magnitude (V) | +4.82[2] (4.98 + 6.95)[3] |
| Characteristics | |
| Spectral type | A7 III + A8 V:[4] |
| Astrometry | |
| Radial velocity (Rv) | −10.4±2.1[2] km/s |
| Proper motion (μ) | RA: −95.54[1] mas/yr Dec.: +23.75[1] mas/yr |
| Parallax (π) | 16.42 ± 0.53 mas[1] |
| Distance | 199 ± 6 ly (61 ± 2 pc) |
| Absolute magnitude (MV) | 0.90[2] |
| Orbit[5] | |
| Period (P) | 228 yr |
| Semi-major axis (a) | 1.02″ |
| Eccentricity (e) | 0.80 |
| Inclination (i) | 147° |
| Longitude of the node (Ω) | 87° |
| Periastron epoch (T) | 1864.0 |
| Argument of periastron (ω) (secondary) | 159° |
| Details | |
| 25 CVn A | |
| Mass | 2.23[6] M☉ |
| Surface gravity (log g) | 3.85[7] cgs |
| Temperature | 7,609±259[7] K |
| Rotational velocity (v sin i) | 235[8] km/s |
| Age | 659[7] Myr |
| 25 CVn B | |
| Mass | 1.58[6] M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
This is a wide binary system with an orbital period of 228 years and an eccentricity of 0.80.[5] As of 2001, they had a projected separation of 107.0 AU.[6] The magnitude 4.98[3] primary, component A, has a stellar classification of A7 III,[4] which matches an A-type giant star. It is 659[7] million years old with a projected rotational velocity of 235 km/s. This rate of spin is giving the star an oblate shape with an equatorial bulge that is an estimated 27% larger than the polar radius.[8] The companion, component B, is a magnitude 6.95[3] A-type main-sequence star with a class of A8 V:.[4] The ':' suffix indicates some uncertainty in the classification of this star.
References
edit- ^ 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, S2CID 18759600.
- ^ a b c d e 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. S2CID 119257644.
- ^ a b c Mason, B. D.; et al. (December 2001), "The Washington Visual Double Star Catalog (WDS), Version 2019-01-21", The Astronomical Journal, 122 (6), U. S. Naval Observatory, Washington D.C.: 3466–3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
- ^ a b c Stephenson, C. B.; Sanwal, N. B. (June 1969), "The masses of stars above the main sequence", Astronomical Journal, 74: 689–704, Bibcode:1969AJ.....74..689S, doi:10.1086/110845.
- ^ a b Söderhjelm, Staffan (1999), "Visual binary orbits and masses POST HIPPARCOS", Astronomy and Astrophysics, 341: 121–140, Bibcode:1999A&A...341..121S.
- ^ a b c De Rosa, R. J.; Patience, J.; Wilson, P. A.; Schneider, A.; Wiktorowicz, S. J.; Vigan, A.; Marois, C.; Song, I.; Macintosh, B.; Graham, J. R.; Doyon, R.; Bessell, M. S.; Thomas, S.; Lai, O. (2014), "The VAST Survey - III. The multiplicity of A-type stars within 75 pc", Monthly Notices of the Royal Astronomical Society, 437 (2): 1216–1240, arXiv:1311.7141, Bibcode:2014MNRAS.437.1216D, doi:10.1093/mnras/stt1932.
- ^ a b c d David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
- ^ a b van Belle, Gerard T. (March 2012), "Interferometric observations of rapidly rotating stars", The Astronomy and Astrophysics Review, 20 (1): 51, arXiv:1204.2572, Bibcode:2012A&ARv..20...51V, doi:10.1007/s00159-012-0051-2, S2CID 119273474.
- ^ "25 CVn". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-27.
- ^ Eggleton, P. P.; Tokovinin, A. A. (2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.