Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Triangulum Australe |
Right ascension | 16h 35m 44.81924s[1] |
Declination | −65° 29′ 43.4478″[1] |
Apparent magnitude (V) | +5.50[2] |
Characteristics | |
Spectral type | G8-K0 III[3] |
U−B color index | +0.73[2] |
B−V color index | +0.93[2] |
Astrometry | |
Radial velocity (Rv) | 9.6±2.8[4] km/s |
Proper motion (μ) | RA: +35.117[1] mas/yr Dec.: −29.356[1] mas/yr |
Parallax (π) | 9.7682 ± 0.0849 mas[1] |
Distance | 334 ± 3 ly (102.4 ± 0.9 pc) |
Absolute magnitude (MV) | +0.40[5] |
Details | |
Radius | 11[6] R☉ |
Luminosity | 79[7] L☉ |
Surface gravity (log g) | 2.81±0.08[8] cgs |
Temperature | 5,039±31[8] K |
Metallicity [Fe/H] | −0.05±0.03[8] dex |
Other designations | |
Database references | |
SIMBAD | data |
θ Trianguli Australis, Latinized as Theta Trianguli Australis, is a single[10] star in the southern constellation of Triangulum Australe. It is visible to the naked eye as a dim, yellow-hued star with an apparent visual magnitude of +5.50.[2] The star is located about 334 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +10 km/s.[4]
This is an evolved G/K-type giant star with a stellar classification of G8-K0 III.[3] The interferometry-measured angular diameter of the primary component is 0.99±0.01 mas,[11] which, at its estimated distance, equates to a physical radius of about 11 times the radius of the Sun.[6] The star is radiating 79[7] times the Sun's luminosity from its photosphere at an effective temperature of 5,039 K.[8]