Kappa Tucanae
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Tucana |
| Right ascension | 01h 15m 46.16226s[1] |
| Declination | −68° 52′ 33.3356″[1] |
| Apparent magnitude (V) | +4.25[2] (5.00 + 7.74 + 7.84 + 8.44)[3] |
| Characteristics | |
| Spectral type | F6IV + G5V + K2V + K3V |
| B−V color index | 0.48[4] |
| Astrometry | |
| Radial velocity (Rv) | +7.7±1.7[5] km/s |
| Proper motion (μ) | RA: +412.11[1] mas/yr Dec.: +127.74[1] mas/yr |
| Parallax (π) | 47.72 ± 0.41 mas[1] |
| Distance | 68.3 ± 0.6 ly (21.0 ± 0.2 pc) |
| Absolute magnitude (MV) | 3.50[4] |
| Orbit[6] | |
| Period (P) | 857.0 yr |
| Semi-major axis (a) | 5.960″ |
| Eccentricity (e) | 0.384 |
| Inclination (i) | 127.1° |
| Longitude of the node (Ω) | 10.3° |
| Periastron epoch (T) | 1763.50 |
| Argument of periastron (ω) (secondary) | 284.9° |
| Details[7] | |
| κ Tuc Aa | |
| Mass | 1.35 M☉ |
| Temperature | 6,513 K |
| Rotational velocity (v sin i) | 61.1±3.1[4] km/s |
| κ Tuc Ab | |
| Mass | 0.2 or 0.4 M☉ |
| κ Tuc B | |
| Mass | 0.88 M☉ |
| Temperature | 5,145 K |
| κ Tuc C | |
| Mass | 0.86 M☉ |
| Temperature | 5,062 K |
| κ Tuc D | |
| Mass | 0.80 M☉ |
| Temperature | 4,850 K |
| Other designations | |
| Database references | |
| SIMBAD | data |
Kappa Tucanae, Latinised from, κ Tucanae, is a quintuple[7] star system in the southern constellation Tucana. It is visible to the naked eye as a faint point of light with a combined apparent visual magnitude of +4.25.[2] The system is located approximately 68 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +8 km/s.[5]
The system consists of two binary pairs separated by 5.3 arcminutes. The primary star, Kappa Tucanae Aa, is a F-type subgiant with an apparent magnitude of 4.88. This star makes an astrometric binary together with Kappa Tucanae Ab, which has an orbital period of either 22 of 120 years and a mass of 0.2 or 0.4 solar masses, being too faint to be detected using photometry. Its binary companion, Kappa Tucanae B, has a magnitude of 7.54[7] and is located about 6″ away from the primary. It completes an orbit around the primary every 857 years,[6] but the orbital period is still very uncertain.[7]
The other binary pair, the magnitude +7.76 C, and the magnitude +8.26 D, are closer to one another, at 1.09 arcseconds. They orbit each other once every 85.12 years.[7]
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, S2CID 18759600.
- ^ a b c "Kappa Tucanae". SIMBAD. Centre de données astronomiques de Strasbourg.
- ^ Mason, B. D.; et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
- ^ a b c Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics, 542: A116, arXiv:1204.2459, Bibcode:2012A&A...542A.116A, doi:10.1051/0004-6361/201118724, S2CID 53666672.
- ^ a b 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 "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. Archived from the original on 2017-08-01. Retrieved 2017-07-01.
- ^ a b c d e Tokovinin, Andrei (2020-06-01). "Nearby Quintuple Systems κ Tucanae and ξ Scorpii". The Astronomical Journal. 159 (6): 265. arXiv:2005.04057. Bibcode:2020AJ....159..265T. doi:10.3847/1538-3881/ab8af1. ISSN 0004-6256.
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