Yellow Stars

We know there are red stars, and we know there are white and even blue stars, but are there yellow stars? Is it possible to get the right temperature of star to have it look yellow? You might think that the Sun is yellow, but actually, the light coming from the Sun is pure white; it goes a little more yellow when it passes through the Earth’s atmosphere.

It’s actually difficult to see a pure yellow star. That’s because stars give off all the colors of the rainbow. The color we see is actually an average of all the photons reaching our eyes. Some are red, some are yellow and some are blue. The temperature of a star defines the color it will give off. Above 6,000 Kelvin, and the star appears white. From 5,000 – 6,000 Kelvin, the star appears yellowish, and below 5,000 Kelvin, the star looks yellowish-orange. So instead of being pure yellow, as star like that is going to be yellow mixed with something else.

A star with less than 5,000 Kelvin will be a lower-mass star; perhaps 75% the mass of the Sun. This means that it will have a lower luminosity and use up its fuel more slowly. It will live much longer than the Sun.

We have written many articles about stars here on Universe Today. Here’s an article about a yellow star, somewhat similar to our own Sun.

If you’d like more information on stars, check out Hubblesite’s News Releases about Stars, and here’s the stars and galaxies homepage.

We have recorded several episodes of Astronomy Cast about stars. Here are two that you might find helpful: Episode 12: Where Do Baby Stars Come From, and Episode 13: Where Do Stars Go When they Die?