Gamma Trianguli Australis
Gamma Trianguli Australis, Latinized from γ Trianguli Australis, is a 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. It is the third-brightest member of this constellation with an apparent visual magnitude of +2.87. Based upon parallax measurements, Gamma Trianguli Australis is located at a distance of about from Earth.
Characteristics
The spectrum of this star matches a stellar classification of A1 III, which identifies it as a giant star. It could be also a subgiant. An unusual abundance of the element europium demonstrates it to be a peculiar, or Ap star. However, its classification as a chemically peculiar star is doubtful. Most stars of this type are slow rotators, but Gamma Trianguli Australis displays a very high rate of rotation with a projected rotational velocity of 199 km s−1.At a mass of 3.04solar masses, Gamma Trianguli Australis was a late B-type star in the main sequence. Being 350 million years old, it has recently begun its expansion towards a red giant. Its radius is either or . The star is emitting a luminosity equivalent to 250solar luminosities. Its surface has an effective temperature of. This is around hotter than the Sun and gives it a white hue, typical of A-type stars.
This star 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.