Kappa Tucanae

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]
Distance68.3 ± 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
Mass1.35 M
Temperature6,513 K
Rotational velocity (v sin i)61.1±3.1[4] km/s
κ Tuc Ab
Mass0.2 or 0.4 M
κ Tuc B
Mass0.88 M
Temperature5,145 K
κ Tuc C
Mass0.86 M
Temperature5,062 K
κ Tuc D
Mass0.80 M
Temperature4,850 K
Other designations
κ Tuc, HD 7788, HIP 5896, HR 377, SAO 248346[2]
Database references
SIMBADdata

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]

  1. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c "Kappa Tucanae". SIMBAD. Centre de données astronomiques de Strasbourg.
  3. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference vonEiff2012 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference ORB6 was invoked but never defined (see the help page).
  7. ^ a b c d e Cite error: The named reference Tokovinin2020 was invoked but never defined (see the help page).