Triangulum Australe

Triangulum Australe
Constellation
Triangulum Australe
AbbreviationTrA
GenitiveTrianguli Australis
Pronunciation/trˈæŋɡjʊləm ɒsˈtrl/,
genitive /trˈæŋɡjʊl ɒˈstrlɪs/
Symbolismthe Southern Triangle
Right ascension14h 56.4m to 17h 13.5m [1]
Declination−60.26° to −70.51°[1]
QuadrantSQ3
Area110 sq. deg. (83rd)
Main stars3
Bayer/Flamsteed
stars
10
Stars with planets1
Stars brighter than 3.00m3
Stars within 10.00 pc (32.62 ly)0
Brightest starα TrA (Atria) (1.91m)
Messier objects0
Meteor showers0
Bordering
constellations
Norma
Ara
Circinus
Apus
Visible at latitudes between +25° and −90°.
Best visible at 21:00 (9 p.m.) during the month of July.

Triangulum 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 and is derived from the acute, almost equilateral pattern of its three brightest stars. It was first depicted on a celestial globe as Triangulus Antarcticus by Petrus Plancius in 1589, and later with more accuracy and its current name by Johann Bayer in his 1603 Uranometria. 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, as well as the 42nd-brightest star in the night sky. Completing the triangle are the two white main sequence stars Beta and Gamma Trianguli 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 Great Attractor, the gravitational center of the Laniakea Supercluster which includes the Milky Way galaxy, straddles between Triangulum Australe and the neighboring constellation Norma.[2]

  1. ^ a b IAU Constellation Boundary.
  2. ^ "Hubble focuses on "the Great Attractor"". NASA. 18 January 2013. Retrieved 24 October 2020.