Meet a star / Carina

Miaplacidus

Miaplacidus is a white star, hotter than the Sun, in the constellation Carina. 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

110 light years

The light you see from Miaplacidus tonight set off about 110 years ago. Everything we know about it is that much out of date.

How bright

230 Suns

It gives out 230 times as much visible light as the Sun. It is one of the hundred brightest stars in the night sky. It is easy to see by eye on a clear night.

Astronomers put its brightness in our sky at magnitude 1.67. Smaller numbers are brighter, and the faintest stars the eye can see are about 6.

How hot

About 9,300 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.

MiaplacidusThe Sun

In your sky now

Working it out…

Its names

Its own name
Miaplacidus
By constellation (Bayer)
Beta Carinae
Hipparcos catalogue
HIP 45238
Henry Draper catalogue
HD 80007
Spectral type
A2IV

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.