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I was going through the preliminary papers of other schools and found a question that I did not know. It was "Why sunlight appears yellow?". Can anyone answer it?

Qmechanic
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6 Answers6

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Color of Sunlight as seen on Earth's surface during day is yellow due to Rayleigh Scattering.

Our Sun is actually white (mixture of all wavelengths of visible spectrum) if we see it from outer space or high-altitude airplanes. Our atmosphere scatters shorter to bigger wavelengths color from sunlight when the white light travels through it. During day, it scatters violet and blue colors leaving yellowish sunlight (the reason why sky is blue and sunlight is yellow). During morning and evening, the sun appears reddish because light rays needs to travel longer distance in atmosphere which causes scattering of yellow light too.

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It's not. It's white.

At least, most of the time it's white. When the Sun is near the horizon, and its light is passing through ~2000km of atmosphere rather than through only ~20km, then the blueish end of the spectrum is scattered out, and the Sun looks reddish/yellow.

But when higher in the sky the Sun looks white. We just don't look at it.

Check the colour of the Moon (which is just reflecting the Sun's light) in the sky during the day or night to confirm.

Images of the Sun, whether by crayon or telescope/camera, are coloured yellow because that's what we expect to see.

(It's not pure white as in an equal intensity at every visible frequency - there's a flattish peak around green light and it tapers away quickly towards UV and much slower towards IR.)

Errol Hunt
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The reason why the sun is yellow is because the color is determined by additive combination of its component spectrum.

In other words, the sun emits a range of light that we can see, from violet to red, at different intensities. To compute the net color, the color we see, you must add together the radiation. In the case of the sun, the dominant wavelengths are green-yellow-red. Those are the wavelengths with the greatest intensity and total energy. If you add green plus red, you get yellow. The sun also emits, for example, blue light, but that light is overpowered by the green and red light.

Note that this is for a human. Other creatures might see a different color. For example, cats can see farther into the red part of the spectrum than humans can. Therefore, to a cat, the sun will appear slightly more reddish orange than it appears to us.

Ambrose Swasey
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I think this is because of the temperature of the earth.Stars with less temperature are red in colour as visualized by us. stars with higher temp. than sun are blue. however it is actually white

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The reason, for which the color of sunlight is yellow, is scattering. We know that sun is perfect black body and emite radiations of all wavelengths ( Visible spectrum [VIBGYOR] and invisible spectrum [Infrared etc.]).

The frequency of blue color is high while the wavelength is short. This results in scattering of blue(including The whole VIB spectrum) color, as the atmosphere contains heavy dust particles having greater diameter then wavelength of blue color(VIB spectrum), thus resulting in yellowish sunlight. This is also the reason for why sky is blue...

Ashu
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Our sun's surface temperature is about 5000K, which corresponds to a peak in the spectrum in the wavelength of yellow visible light.

WIMP
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