Zeta Trianguli Australis

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Zeta Trianguli Australis
Observation data
Epoch J2000      Equinox J2000
Constellation Triangulum Australe
Right ascension 16h 28m 28.14362s[1]
Declination −70° 05′ 03.8419″[1]
Apparent magnitude (V) 4.90[2]
Spectral type F9 V[3]
U−B color index +0.02[2]
B−V color index +0.55[4]
Radial velocity (Rv) +8.3[5] km/s
Proper motion (μ) RA: 199.97[1] mas/yr
Dec.: 110.97[1] mas/yr
Parallax (π) 82.53 ± 0.52[1] mas
Distance 39.5 ± 0.2 ly
(12.12 ± 0.08 pc)
Absolute magnitude (MV) 4.49[6]
Period (P) 12.97662 ± 0.00017 d
Eccentricity (e) 0.01442 ± 0.00021
Periastron epoch (T) JD 2452752.31955
Argument of periastron (ω)
252.98° ± 0.80°
Semi-amplitude (K1)
7.4988 ± 0.0016 km/s
ζ TrA A
Mass 1.12[8] M
Metallicity [Fe/H] –0.18[4] dex
Rotation 13 days[4]
Rotational velocity (v sin i) 3.23[9] km/s
Age 600–900[10] Myr
ζ TrA B
Mass 0.40[8] M
Other designations
CD -69°2558, FK5 610, GCTP 3719.00, Gl 624, HD 147584, HIP 80686, HR 6098, LTT 6558, SAO 253554.
Database references

Zeta Trianguli Australis (ζ TrA) is a spectroscopic binary in the constellation Triangulum Australe. It is approximately 39.5 light years from Earth.

The binary's composite spectral class is F9V and its combined apparent magnitude is +4.90. The pair orbit each other once every 13 days, and the orbital eccentricity is a low 0.014, making it nearly circular.[7]

Somewhat surprisingly for a star located at 70° S, it is a candidate swarm member of the Ursa Major moving group.[11] However, there is some evidence to the contrary.[4]


  1. ^ a b c d e van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752v1Freely accessible, doi:10.1051/0004-6361:20078357.  Note: see VizieR catalogue I/311.
  2. ^ a b Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data. SIMBAD, Bibcode:1986EgUBV........0M. 
  3. ^ Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, Bibcode:2006AJ....132..161G, arXiv:astro-ph/0603770Freely accessible, doi:10.1086/504637. 
  4. ^ a b c d Maldonado, J.; et al. (October 2010), "A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups", Astronomy and Astrophysics, 521: A12, Bibcode:2010A&A...521A..12M, arXiv:1007.1132Freely accessible, doi:10.1051/0004-6361/201014948. 
  5. ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065. 
  6. ^ Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, Bibcode:2009A&A...501..941H, arXiv:0811.3982Freely accessible, doi:10.1051/0004-6361/200811191. 
  7. ^ a b Skuljan, Jovan (2004), "Accurate orbital parameters for the bright southern spectroscopic binary ζ Trianguli Australis – an interesting case of a near-circular orbit", Monthly Notices of the Royal Astronomical Society, 352: 975, Bibcode:2004MNRAS.352..975S, doi:10.1111/j.1365-2966.2004.07988.x. 
  8. ^ a b Tokovinin, Andrei (April 2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal, 147 (4): 14, Bibcode:2014AJ....147...87T, arXiv:1401.6827Freely accessible, doi:10.1088/0004-6256/147/4/87, 87. 
  9. ^ Martínez-Arnáiz, R.; et al. (September 2010), "Chromospheric activity and rotation of FGK stars in the solar vicinity. An estimation of the radial velocity jitter", Astronomy and Astrophysics, 520: A79, Bibcode:2010A&A...520A..79M, arXiv:1002.4391Freely accessible, doi:10.1051/0004-6361/200913725. 
  10. ^ Mamajek, Eric E.; Hillenbrand, Lynne A. (November 2008), "Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics", The Astrophysical Journal, 687 (2): 1264–1293, Bibcode:2008ApJ...687.1264M, arXiv:0807.1686Freely accessible, doi:10.1086/591785. 
  11. ^ Croswell, Ken (2005). "Descendants of the Dipper". Astronomy. 33 (3): 40–45. ISSN 0091-6358.