Zeta Trianguli Australis
Binary star system in the constellation Triangulum Australe / From Wikipedia, the free encyclopedia
Zeta Trianguli Australis (ζ TrA) is a spectroscopic binary in the constellation Triangulum Australe. It is approximately 39.5 light years from Earth.
Quick Facts Observation data Epoch J2000 Equinox J2000, Constellation ...
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] |
Distance | 39.5 ± 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 | |
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 | |
Database references | |
SIMBAD | data |
ARICNS | data |
Close
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]