Yuyu
Yuyu is an orange star, cooler than the Sun, in the constellation Cancer.
How far
330 light years
The light you see from Yuyu tonight set off about 330 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 Everything we know about it is that much out of date.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
220 Suns
It gives out 220 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 4.03. Smaller numbers are brighter, and the faintest stars the eye can see are about 6.
How hot
About 4,700 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.
YuyuThe Sun
In your sky now
Working it out…
Its names
- Its own name
- Yuyu
- By constellation (Bayer)
- Iota Cancri
- Hipparcos catalogue
- HIP 43103
- Henry Draper catalogue
- HD 74739
- Spectral type
- G8Iab
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.