Are you sure you know the answer? Your eyes could easily deceive you. That’s why science tells us what the true color of the Sun is. And why our eyes see it differently. Andrei Malikhin from the Space Research Institute explains.
Yellow or white?
The debate about the color of the Sun arises because of what astronomer Alastair Gunn said. He indicated that the real color of the Sun is white. But that the eyes generally perceive it as yellow.
“The Sun peaks at a wavelength that we would normally describe as green. But the human eye does not perceive light by averaging the different colors of the spectrum together. A slight excess of green light does not look green to the human eye, it looks white. The Sun would have to emit only green light for us to see it as green,” the astronomer explained.
Andrei Malikhin noted that stars are considered to be totally black bodies. They are objects that absorb any stream of light and do not reflect it. If you shine a torch on the Sun, it will not reflect anything.
The radiance of the stars comes from the temperature of their surface. Each temperature is characterized by emission at its own wavelength. A red dwarf would correspond to 3,000 degrees Kelvin. For the Sun the radiation curve would correspond to about 5,500 degrees Kelvin.
“Summarizing all this we see the following: the maximum of the Sun’s radiation is observed at a wavelength of 501 nanometers. This color could be called green or turquoise. The range from 500 to 570 nanometers can be called green,” Malijin said. However, the scientist believes that one should not jump to conclusions.
Eyes that choose
Color denotes a person’s perception of a given electromagnetic radiation. Human eyes are limited in the extent of color perception by three photoreceptors. The most sensitive receptor is the L-receptor, responsible for the yellow-red range. The M receptors are responsible for the green-yellow range. And the S receptors are responsible for violet-blue.
The L-receptor most easily picks up the signal. A person should almost always see things in shades of red. To compensate for the difference in the received signals, the brain brings them into chromatic balance.
But then, what is the true color of the Sun? “The Sun’s radiation illuminates almost uniformly the L, M, and S receptors. Our brain corrects for this. And it tells us that each color is approximately equal. So we end up seeing white. That’s what the original paper by the British scientist says,” Malijin concluded.