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] or +4.86[3]
(5.00 + 7.74 + 7.84 + 8.44)[4]
Characteristics
Spectral type F6 IV + G5 V + K2V + ?[5]
B−V color index 0.48[6]
Astrometry
Radial velocity (Rv)+7.7±1.7[2] 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]
Distance68.3 ± 0.6 ly
(21.0 ± 0.2 pc)
Absolute magnitude (MV)3.50[6]
Orbit[7]
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
κ Tuc A
Mass1.37[8] M☉
Temperature6,366[6] K
Rotational velocity (v sin i)61.1±3.1[6] km/s
κ Tuc B
Mass0.85[8] M☉
Other designations
κ Tuc, HD 7788, HIP 5896, HR 377, SAO 248346[9]
Database references
SIMBADdata

Kappa Tucanae, Latinised from, κ Tucanae, is a quadruple[5] 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 either +4.25[2] or +4.86,[3] depending on the source. 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.[2]

The system consists of two binary pairs separated by 5.3 arcminutes. The brightest star, Kappa Tucanae A, is a yellow-white F-type subgiant with an apparent magnitude of +5.0. Its binary companion, Kappa Tucanae B, has a magnitude of 7.74 and is located about 6″ away from the primary. It completes an orbit around the primary every 857 years.[7]

The other binary pair, the magnitude +7.8 C, and the magnitude +8.4 D, are closer to one another, at 1.12 arcseconds, or at least 23 astronomical units. They orbit each other once every 86.2 years.

References

  1. ^ 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.
  2. ^ a b c d 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.
  3. ^ a b Hoffleit, D.; Warren, Jr., W. H. (1991), The Bright Star Catalogue (5th Revised ed.), retrieved 2019-09-16.
  4. ^ 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.
  5. ^ a b 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  6. ^ a b c d 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.
  7. ^ 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.
  8. ^ a b Tokovinin, A.; Kiyaeva, O. (2015). "Eccentricity distribution of wide binaries". Monthly Notices of the Royal Astronomical Society. 456 (2): 2070. arXiv:1512.00278. Bibcode:2016MNRAS.456.2070T. doi:10.1093/mnras/stv2825.
  9. ^ "kap Tuc -- Double or multiple star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-04-21.
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