Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Triangulum Australe |
Right ascension | 15h 18m 54.58198s[1] |
Declination | –68° 40′ 46.3654″[1] |
Apparent magnitude (V) | +2.87[2] |
Characteristics | |
Spectral type | A1 V[3][4] |
U−B color index | –0.02[5] |
B−V color index | +0.00[5] |
Astrometry | |
Radial velocity (Rv) | –3.0[2] km/s |
Proper motion (μ) | RA: –66.58[1] mas/yr Dec.: –32.31[1] mas/yr |
Parallax (π) | 17.74 ± 0.12 mas[1] |
Distance | 184 ± 1 ly (56.4 ± 0.4 pc) |
Absolute magnitude (MV) | −0.89[6] |
Details | |
Mass | 1.99[7] M☉ |
Radius | 5.86[8] R☉ |
Luminosity | 249[9] L☉ |
Surface gravity (log g) | 3.39[7] cgs |
Temperature | 9,306±316[7] K |
Rotational velocity (v sin i) | 199[4] km/s |
Age | 260[10] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Gamma Trianguli Australis, Latinized from γ Trianguli Australis, is a single,[12] white-hued star in the southern constellation of Triangulum Australe. Along with Alpha and Beta Trianguli Australis it forms a prominent triangular asterism that gives the constellation its name (Latin for southern triangle). It is the third-brightest member of this constellation with an apparent visual magnitude of +2.87.[2] Based upon parallax measurements, Gamma Trianguli Australis is located at a distance of about 184 light-years (56 parsecs) from Earth.[1]
The spectrum of this star matches a stellar classification of A1 V,[3][4] which identifies it as an A-type main sequence star that is generating energy through the nuclear fusion of hydrogen at its core. An unusual abundance of the element europium demonstrates it to be a peculiar, or Ap star.[13] Most stars of this type are slow rotators,[14] but Gamma Trianguli Australis displays a very high rate of rotation with a projected rotational velocity of 199 km s−1.[4] It has an estimated age of 260 million years.[10]
This system shows an excess emission of infrared radiation, suggesting that there is a circumstellar disk of dust orbiting this star. The mean temperature of the emission is 50 K, corresponding to a separation from the star of 481 astronomical units.[8]
γ TrA appears on the flag of Brazil, symbolising the state of Paraná.[15]