Triangulum Australe

Triangulum Australe

Triangulum Australe is a small constellation in the far Southern Celestial Hemisphere. It was first depicted on a celestial globe as Triangulus Antarcticus by Petrus Plancius in 1589. Alpha Trianguli Australis, known as Atria, is a second-magnitude orange giant and the brightest star in the constellation.

About Triangulum Australe in brief

Summary Triangulum AustraleTriangulum Australe is a small constellation in the far Southern Celestial Hemisphere. Its name is Latin for \”the southern triangle\”, which distinguishes it from Triangulum in the northern sky. It was first depicted on a celestial globe as Triangulus Antarcticus by Petrus Plancius in 1589. The French explorer and astronomer Nicolas Louis de Lacaille charted and gave the brighter stars their Bayer designations in 1756. Alpha Trianguli Australis, known as Atria, is a second-magnitude orange giant and the brightest star in the constellation. Completing the triangle are the two white main sequence stars Beta and Gamma Triangulia Australis. Although the constellation lies in the Milky Way and contains many stars, deep-sky objects are not prominent. Notable features include the open cluster NGC 6025 and planetary nebula NGC 5979. The Wardaman people of the Northern Territory in Australia perceived the stars as the tail of the Rainbow Serpent, which stretched out from near Crux across to Scorpius. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is \”TrA\”.

The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of 18 segments. In the equatorial coordinate system the right ascension and declination of these borders lie between 14h 56 4m and 17h 5m while the declination is between 26° 26 −70 51° and 13h 13m m on p 23 August each year. In August, each year on 9 p.m. the constellation culminates each year at 9:23 p.M. (GMT) The three brightest stars, Alpha, Beta and gamma, make up the triangle that is the 42nd-brightest star of the night sky. The constellation lies near the Pointers, with only Circinus in between. It lies too far south in the celestial southern hemisphere to be visible from Europe, yet is circumpolar from most of the southern hemisphere. It is bordered by Norma to the north, Circinus to the west, Apus to the south and Ara to the east. The first depiction of the constellation was provided by Flemish astronomer and clergyman Petrus. Plancius on a ​32 1⁄2-cm diameter celestial globe published in Amsterdam by Dutch cartographer Jacob Floris van Langren in 1504.