Is it yellow because from Earth it usually looks yellow to us? Or is it white because the sun gives off all wavelengths of light (white light)? Or is it some other color?
In: Planetary Science
With regard to other stars, would a “blue” star or a “red” giant also be producing mostly white light (to our eyes)?
This is a tricky question, because ‘color’ is basically defined by how something differs from the light given out by the sun.
Your sense of color has evolved to tell you about the properties of surfaces around you. Specifically, which parts of the sun’s light sink into them and which bounce off.
So a strawberry looks red because it’s absorbed the green looking parts of the sunlight, and vice versa for the green leaves around it.
Each color you can see represents a different direction in which sunlight can be skewed.
So what color is the sun itself? Arguably it doesn’t have a color, in the same way that still air has no sound.
The sun is our perceptual zero point in color space, and every ‘white’ artificial source of light you’ve ever seen has simply been trying to spoof it.
The sun is by definition white, it is all the colors we have evolved to see in exactly the ratio we evolved to see them. It emits more light than we can see though
All color is really an illusion. But the sun would/does appear white above the earth’s atmosphere.
These comments confused me even more, but [this](https://youtu.be/dX6qouLEo2E?si=70sAkoUxtLkJeaBl) video helped me understand it. If I’m correct, the sun is white, which is all colors on the spectrum. The atmosphere is like a prism, which is why it’s yellow at sunrise, white during the day, and orange at sunset. It’s also blue from Mars.
Everyone else is talking about the physics, but I see this as actually as a question of colorimetry, because color is a perceptual phenomenon of the human visual system, it’s not just wavelengths and energy.
The sun is a black body with temperature of ~5800K, which means if you were to be able to look directly at it from outer space, without the atmosphere in the way, and somehow also without blinding yourself, the color would be somewhere in between a 5000K and 6500K LED. The atmosphere interferes with this throughout the day to give different colors as viewed on earth, ranging from around 6500K to 2700K.
Now, all these colors along the [black body locus](https://en.wikipedia.org/wiki/Planckian_locus#/media/File:PlanckianLocus.png) (6500K, 5000K, 4000K, 3000K, 2700K, 1800K, etc. and everything in between), are considered “white”, even though they’re obviously very different colors and some are redder or bluer, because the spectrum of the light source actually changes our color perception though a system called “chromatic adaptation”. Basically, a white piece of paper always looks like the same color, no matter what time of day it is, because the brain adjusts for the color of the sun.
So from a psychovisual perspective, you could say that the sun is always white, no matter what time of day, even in outer space.
If you don’t want to take chromatic adaptation into account and want to directly compare it to the color of another light source, then you can get a LED that is close to 5800K and it will be a reasonable approximation.
Of course, another complication is that brightness actually also slightly affects color perception. Even worse, at the brightness of the sun, which is quite literally blindingly bright, our color models completely break down. So you could also say that the sun has no color when you’re directly looking at it, because… well you’d be blind.
It could be brown
It could be blue
It could be violet sky
It could be hurtful
It could be purple
It could be anything you like
The Sun is white. If you look up at the sun mid day, it is white. But if you look at the sun at dawn or sunset, the color appears to change because the light is being filtered through more and more air.
Earths air scatters the light as it passes through it. But not equally, it scatters blue light more than red. This is why the sky is blue, and the sun is deep red at sunset.
The actual color of the Sun is white. Even though it peaks in the green wavelength of visible light, the sheer amount of light coming from the Sun makes this a moot point. It still appears white.
Anyone that says they know what color a star is, is misinformed at best, lying at worst.
What we humans see, here in earth’s atmosphere, is not accurate. Saying starlight is white is also partially wrong, as it contains all wavelengths of electromagnetic spectrum, something we humans only see about 4% of.
Starlight is full spectrum light, at max intensity, our eyes, and most of our optical sensors, get washed out in high intensity light, so things become white. When we look at things through other lenses or wavelengths, like xray, nearferred, violet, ultraviolet etc… we see stars as many different colors.
For a five year old, the best explanation is starlight is too bright to define a color, and the earth’s atmosphere absorbs some light making it appear more yellow to our eyes.
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