Astronomy:Kappa Tucanae

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Short description: Quadruple star system in the constellation Tucana
Kappa Tucanae
Observation data
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[1] mas
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. 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode2007A&A...474..653V. 
  2. 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  3. 3.0 3.1 Hoffleit, D.; Warren, Jr., W. H. (1991), The Bright Star Catalogue (5th Revised ed.), http://vizier.u-strasbg.fr/cgi-bin/VizieR?-source=V/50, retrieved 2019-09-16. 
  4. Mason, B. D. et al. (2014), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode2001AJ....122.3466M. 
  5. 5.0 5.1 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, Bibcode2008MNRAS.389..869E. 
  6. 6.0 6.1 6.2 6.3 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, doi:10.1051/0004-6361/201118724, Bibcode2012A&A...542A.116A. 
  7. 7.0 7.1 "Sixth Catalog of Orbits of Visual Binary Stars". United States Naval Observatory. http://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/wds/orb6. 
  8. 8.0 8.1 Tokovinin, A.; Kiyaeva, O. (2015). "Eccentricity distribution of wide binaries". Monthly Notices of the Royal Astronomical Society 456 (2): 2070. doi:10.1093/mnras/stv2825. Bibcode2016MNRAS.456.2070T. 
  9. "kap Tuc -- Double or multiple star", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=kap+Tuc, retrieved 2017-04-21.