Meet a star / Ophiuchus

Mahsati

Mahsati is an orange star, cooler than the Sun, in the constellation Ophiuchus.

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

How far

610 light years

The light you see from Mahsati tonight set off about 610 years ago. Everything we know about it is that much out of date.

Distances this great are hard to measure, and this one could be out by a fifth or more.

How bright

13 Suns

It gives out 13 times as much visible light as the Sun. It is too faint to see without a telescope.

Astronomers put its brightness in our sky at magnitude 8.38. Smaller numbers are brighter, and the faintest stars the eye can see are about 6.

How hot

About 5,000 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.

MahsatiThe Sun

Its names

Its own name
Mahsati
Hipparcos catalogue
HIP 82651
Henry Draper catalogue
HD 152581
Spectral type
K0

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.