Meet a star / Gemini

Wasat

Wasat is a yellow-white star, a little hotter than the Sun, in the constellation Gemini. It is a subgiant: a star just beginning to leave the long, steady part of its life.

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

How far

60 light years

The light you see from Wasat tonight set off about 60 years ago. Everything we know about it is that much out of date.

How bright

12 Suns

It gives out 12 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 3.50. Smaller numbers are brighter, and the faintest stars the eye can see are about 6.

How hot

About 7,000 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.

WasatThe Sun

In your sky now

Working it out…

Its names

Its own name
Wasat
By constellation (Bayer)
Delta Geminorum
Hipparcos catalogue
HIP 35550
Henry Draper catalogue
HD 56986
Spectral type
F0IV

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.

To read more: Colour and brightness, How stars live and die, Measuring distance.