Meet a star / Vulpecula

29 Vulpeculae

29 Vulpeculae is a white star, hotter than the Sun, in the constellation Vulpecula. It is in the long, steady part of its life, making helium from hydrogen in its core, as the Sun is.

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

How far

230 light years

The light you see from 29 Vulpeculae tonight set off about 230 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 Everything we know about it is that much out of date.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

53 Suns

It gives out 53 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 4.81. Smaller numbers are brighter, and the faintest stars the eye can see are about 6.

How hot

About 10,500 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.

29 VulpeculaeThe Sun

In your sky now

Working it out…

Its names

It has no name of its own. Its name by constellation is a number and the constellation it is in, from the catalogue of John Flamsteed, the first Astronomer Royal.

By constellation (Flamsteed)
29 Vulpeculae
Hipparcos catalogue
HIP 101867
Henry Draper catalogue
HD 196724
Spectral type
A0V

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.