Zeta Trianguli Australis

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]
Characteristics
Spectral type F9 V[3]
U−B color index +0.02[2]
B−V color index +0.55[4]
Astrometry
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 mas[1]
Distance39.5 ± 0.2 ly
(12.12 ± 0.08 pc)
Absolute magnitude (MV)4.49[6]
Orbit[7]
Period (P)12.97662 ± 0.00017 d
Eccentricity (e)0.01442 ± 0.00021
Periastron epoch (T)JD 2452752.31955
Argument of periastron (ω)
(secondary)		252.98° ± 0.80°
Semi-amplitude (K1)
(primary)		7.4988 ± 0.0016 km/s
Details
ζ TrA A
Mass1.12[8] M☉
Metallicity [Fe/H]–0.18[4] dex
Rotation13 days[4]
Rotational velocity (v sin i)3.23[9] km/s
Age600–900[10] Myr
ζ TrA B
Mass0.40[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
SIMBADdata
ARICNSdata

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 Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference MERMILLIOD was invoked but never defined (see the help page).
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  4. ^ a b c d Cite error: The named reference aaa521_A12 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Holmberg2009 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference mnras352_975 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference aj147_4_87 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference aaa520_A79 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference apj687 was invoked but never defined (see the help page).
  11. ^ Croswell, Ken (2005). "Descendants of the Dipper". Astronomy. 33 (3): 40–45. Bibcode:2005Ast....33c..40C. ISSN 0091-6358.