Triangulum Australe constellation

Triangulum Australe (the Southern Triangle) is a constellation in the southern sky, best seen in the evening in July. Its brightest star is Atria (magnitude 1.92). Triangulum Australe covers 110 square degrees and is the 83rd-largest of the 88 constellations.

Updated: 2026-11-01

Triangulum Australe constellation: the main stars connected by lines, labeled Atria — The shape of Triangulum Australe: its brighter stars joined by the traditional stick figure.

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Detailed star map of Triangulum Australe

Triangulum Australe constellation star map with lines connecting the stars, the brightest stars labeled (Atria), the IAU boundary and neighboring constellations — Map of Triangulum Australe: lines connect the stars of the traditional figure, the dashed line is the official IAU boundary. Star names and Greek letters mark the brightest stars.

Facts

Latin name	Triangulum Australe (genitive: Trianguli Australis)
Abbreviation	TrA
Meaning	the Southern Triangle
Area	110 square degrees (83rd of 88)
Location	right ascension 16.1 h, declination −66°
Visible from	latitudes 19° N to 90° S (whole constellation)
Best month	July (at about 9 pm)
Brightest star	Atria
Stars brighter than magnitude 6	20
Named stars (IAU)	1
Messier objects	none
Neighbors	Apus, Ara, Circinus, Norma

Sources: star positions, magnitudes and colors from the Yale Bright Star Catalogue; constellation boundaries and star names from the IAU; areas and distances from Wikidata; stick figures by M. van der Sluys. How the maps are made.

How to find Triangulum Australe

From 40° N (the USA, southern Europe, Japan) Triangulum Australe never rises completely above the horizon. From 35° S (Australia, South Africa, Argentina) it never sets and stands highest in the south, about 59° up. The months before and after (June and August) are also good: then it is up a couple of hours earlier or later.

Triangulum Australe borders Apus, Ara, Circinus and Norma.

Where Triangulum Australe is in the night sky, shown among its neighbors Apus, Ara, Circinus and Norma — Triangulum Australe (highlighted) among the neighboring constellations. Bright stars are named for orientation.

Stars of Triangulum Australe

Triangulum Australe has 20 stars brighter than magnitude 6, the limit of the naked eye under a dark sky. These are the brightest:

Star	Designation	Magnitude	Type	Distance
Atria	α Trianguli Australis	1.92	K2IIb-IIIa	—
—	β Trianguli Australis	2.85	F2III	—
—	γ Trianguli Australis	2.89	A1V	—
—	δ Trianguli Australis	3.85	G2Ib-IIa	—
—	ε Trianguli Australis	4.11	K1-2III	—

Printable Triangulum Australe map and outline

A black and white version for printing and a plain outline of the Triangulum Australe figure, useful for school projects, worksheets and learning to recognize the shape.

Printable black and white map of the Triangulum Australe constellation with star names, lines and boundary

Triangulum Australe constellation outline: the stick figure of Triangulum Australe without labels

History

Triangulum Australe is introduced by the Dutch navigators Pieter Dirkszoon Keyser and Frederick de Houtman in the 1590s and published by Petrus Plancius and Johann Bayer. Its official boundary was drawn by Eugène Delporte for the International Astronomical Union in 1930.

Questions about Triangulum Australe

What is the brightest star in Triangulum Australe?

Atria, at magnitude 1.92.

When can you see Triangulum Australe?

Triangulum Australe is best seen in the evening in July. The whole constellation is visible from latitudes between 19° N and 90° S.

How many stars are in Triangulum Australe?

20 stars in Triangulum Australe are brighter than magnitude 6 and can be seen with the naked eye under a dark sky; 1 of them have official IAU names.

What does Triangulum Australe mean?

Triangulum Australe means “the Southern Triangle” in Latin. Its abbreviation is TrA and the genitive, used in star names such as α Trianguli Australis, is Trianguli Australis.