Meet a star / Scorpius

Sharjah

Sharjah is a red star, among the coolest, in the constellation Scorpius.

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

How far

47 light years

The light you see from Sharjah tonight set off about 47 years ago. Everything we know about it is that much out of date.

How bright

0.01 of a Sun

It gives out one 190th of the Sun's visible light. It is too faint to see without a telescope.

Astronomers put its brightness in our sky at magnitude 11.34. Smaller numbers are brighter, and the faintest stars the eye can see are about 6.

How hot

About 3,800 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.

SharjahThe Sun

Its names

Its own name
Sharjah
Hipparcos catalogue
HIP 79431

Its spectral type, the code for what kind of star it is, is not in the catalogue.

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.