Meet a star / Cepheus

Tarandus

Tarandus is an orange star, cooler than the Sun, in the constellation Cepheus. It is a bright giant: a star that has left the steady part of its life and swollen up.

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

How far

280 light years

The light you see from Tarandus tonight set off about 280 years ago. Everything we know about it is that much out of date.

At this distance the figure could be out by a tenth or so.

How bright

130 Suns

It gives out 130 times as much visible light as the Sun. It can be seen by eye away from bright lights.

Astronomers put its brightness in our sky at magnitude 4.24. Smaller numbers are brighter, and the faintest stars the eye can see are about 6.

How hot

About 4,300 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.

TarandusThe Sun

In your sky now

Working it out…

Its names

Its own name
Tarandus
Hipparcos catalogue
HIP 5372
Henry Draper catalogue
HD 5848
Spectral type
K2II-III

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.