Triangulum Australe

TrA · genitive Trianguli Australis · southern sky

The Triangulum Australe figure as the IAU defines it, drawn looking south with east to the left — the orientation you see standing outside.

At a glance

Catalogued stars
35
Visible to the eye
35 stars
Brightest star
Atria (1.91)
Best seen
May
Declination span
-69.0° to -63.4°
Nearest star
Zet TrA · 39.5 ly

Visible from everywhere south of about 21°N.

When and where to look for Triangulum Australe

Triangulum Australe crosses the meridian — its highest point in the sky — at local midnight around May, which makes the months from April to June the easiest time to find it in the evening. It spans declinations -69.0° to -63.4°, so visible from everywhere south of about 21°N.

The quickest way to find it is to open the live AR sky map and point your phone at the sky — if Triangulum Australe is above your horizon right now, its figure is drawn in the position it genuinely occupies above you.

Brightest stars in Triangulum Australe

StarMagTypeDistance
AtriaAlp TrA1.91K2IIb-IIIa390.6 ly
Bet TrA2.83F2III40.4 ly
Gam TrA2.87A1V183.9 ly
Del TrA3.86G5II607.4 ly
Eps TrA4.11K0III201.7 ly
Zet TrA4.90F9V39.5 ly

Magnitude runs backwards: lower numbers are brighter, and anything below about 6.5 is beyond the naked eye under a dark sky.

What Triangulum Australe is made of

The catalogue lists 35 stars within Triangulum Australe, of which 35 are magnitude 6.5 or brighter — the limit of what an unaided eye picks up under a genuinely dark sky. The rest need binoculars or a telescope.

Spectral make-up

B6
A10
F5
G3
K9
M1

Spectral class is a temperature ordering, running from O at around 30,000 K down to M below 3,500 K. A constellation is a direction, not a group, so this is simply what happens to lie along that line of sight.

The closest catalogued star in this direction is Zet TrA at 39.5 light years. The most distant is HD 150097 at roughly 1,615 light years — stars that appear side by side here are nothing of the sort.

Nearby constellations