Meet a star / Taurus

63 Tauri

63 Tauri is a white star, hotter than the Sun, in the constellation Taurus.

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

How far

160 light years

The light you see from 63 Tauri tonight set off about 160 years ago. Everything we know about it is that much out of date.

How bright

12 Suns

It gives out 12 times as much visible light as the Sun. It can just be seen by eye from a really dark place.

Astronomers put its brightness in our sky at magnitude 5.64. 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 spectral type, A1m, with a standard table of how hot stars of each type are. It is a guide and not a measurement, and could be out by a tenth or so. Its colour alone would suggest only about 7,400 K. Dust lying between us and the star reddens its light, the way the air reddens the setting Sun, so for this star the type is the better guide. 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.

63 Tauri, as it looks through the dustThe 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)
63 Tauri
Hipparcos catalogue
HIP 20484
Henry Draper catalogue
HD 27749
Spectral type
A1m

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 read from the spectral type with the table of Pecaut and Mamajek (2013), and the words are written for this site.

To read more: Colour and brightness, How stars live and die, Measuring distance.