Triangulum Australe
Triangulum Australe is a Southern Hemisphere constellation otherwise known as the Southern Triangle. It is one of twelve constellations created around 1597 by Petrus Plancius (Wikipedia)from observations by the Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman. Triangulum Australe remains one of the 88 modern constellations defined by the International Astronomical Union (Wikipedia).
Triangulum Australe (abbrev. = TrA; genitive = Trianguli Australis) covers 110 square degrees or 0.27% of the celestial sphere making it the 83rd largest constellation. It contains 35 stars brighter than apparent magnitude 6.5, the brightest star being Atria.
For more information see the entries for Triangulum Australe at Wikipedia and U. Wisconsin. For a chart of Triangulum Australe, see TrA (IAU).