Constellation, TrA
Triangulum Australe: the Southern Triangle
Triangulum Australe covers 110 square degrees of sky, the 83rd largest of the 88. Its brightest star is Atria. It is best placed in the evening sky in July.
Show Triangulum Australe in the live sky
Triangulum Australe at a glance
| Fact | Value |
|---|---|
| IAU abbreviation | TrA |
| Meaning | the Southern Triangle |
| Pronounced | try-ANG-gyuh-lum aw-STRAL-ee |
| Genitive, used in star names | Trianguli Australis (for example a Bayer name such as α Trianguli Australis) |
| Area | 110 square degrees, number 83 of 88 by size |
| Stars to magnitude 6 in our catalogue | 21 |
| Brightest star | Atria, magnitude 1.9 |
| Best seen | Evenings in July, when it is highest at 9 pm |
| Declination range | -70° to -60° |
| Borders | Circinus, Apus, Ara, Norma |
Where on Earth you can see Triangulum Australe
Triangulum Australe spans declinations -70° to -60°. Every part of it rises above the horizon at some moment for observers between latitudes 90°S and 20°N. Some of it can be seen from latitudes 90°S to 30°N. South of 30°S none of it ever sets. This is geometry only: it ignores haze, hills and buildings near the horizon.
From six cities
| City | Latitude | Visibility | Middle at its highest |
|---|---|---|---|
| Pune | 18.5°N | All of it rises | 6° |
| New York | 40.7°N | Never rises | below the horizon |
| London | 51.5°N | Never rises | below the horizon |
| Tromsø | 69.6°N | Never rises | below the horizon |
| Tokyo | 35.7°N | Never rises | below the horizon |
| Sydney | 33.9°S | Never sets | 58° |
Triangulum Australe's named stars
These stars in Triangulum Australe have names approved by the IAU Working Group on Star Names. Magnitude is brightness: a lower number is brighter, and the faintest stars seen with the naked eye on a dark night are about magnitude 6.
| Star | Designation | Magnitude | Distance (light-years) |
|---|---|---|---|
| Atria | α Trianguli Australis | 1.91 | 390 |
Distances are about, from the HYG database (Hipparcos parallax), and "not known" means the catalogue has no reliable parallax for that star.
How these facts were found
The name, meaning and boundaries are the IAU's. Area, borders and the latitude ranges are computed from those boundaries; the brightest star and the star count come from a magnitude-6 star catalogue; star names are matched to the catalogue by Hipparcos number and checked by position. The month is when Triangulum Australe's middle crosses the north-south line of the sky at 9 pm local solar time. See How we know.
Sources
- IAU: The Constellations. Names, meanings, pronunciations and boundaries
- IAU Working Group on Star Names. The official names of stars
- astronomy-engine. The MIT licensed library that does the calculations, run on the page's build machine and in the app
- HYG database v4.4 (astronexus). Distances, spectral types and luminosities, licence CC BY-SA 4.0