Gamma Trianguli Australis

Gamma Trianguli Australis is a white star, hotter than the Sun, in the constellation Triangulum Australe. It is in the long, steady part of its life, making helium from hydrogen in its core, as the Sun is.

Fly to it in 3D Find it on the sky map

A drawing in the star's own colour, worked out from its measured colour index. It is not a photograph.

How far

180 light years

The light you see from Gamma Trianguli Australis tonight set off about 180 years ago. Everything we know about it is that much out of date.

How bright

200 Suns

It gives out 200 times as much visible light as the Sun. It is easy to see by eye on a clear night.

Astronomers put its brightness in our sky at magnitude 2.87. Smaller numbers are brighter, and the faintest stars the eye can see are about 6.

How hot

About 10,000 K

That is the temperature of its surface, worked out from its colour, so it is a guide and not a measurement. It could be out by a few hundred degrees. The Sun's is 5,772 K. Hotter stars are bluer and cooler stars are redder, the same way a poker in a fire goes from red to white.

Gamma Trianguli AustralisThe Sun

In your sky now

Working it out…

Its names

It has no name of its own. Its name by constellation is a Greek letter and the constellation it is in, a way of naming begun by Johann Bayer in 1603.

By constellation (Bayer): Gamma Trianguli Australis
Hipparcos catalogue: HIP 74946
Henry Draper catalogue: HD 135382
Spectral type: A1V

Where this comes from

Distance, brightness, colour and spectral type are from the HYG star database, version 4.4, by David Nash, shared under a Creative Commons Attribution-ShareAlike 4.0 licence. Its distances are those measured by the Hipparcos satellite. The temperature is worked out here from the colour with the formula of Ballesteros (2012), and the words are written for this site.