Ex-NASA astronaut confirmed the space fact that the Sun is white. The dwarf star appears yellow due to the play of physics. Read to know why.
“The Sun Is Actually White”
While many of us may find it difficult to believe, the Sun is white. Sunlight is a mixture of all colors and appears as white, which is highly evident in pictures taken from space. We cannot perceive a singular color for the dwarf star. Instead, when all colors are mixed, our eyes show it as white.
Yellow is not its true color. However, it appears so due to our atmosphere. As per NASA, the shorter wavelength of blue light scatters more efficiently compared to red. However, we lose some blue tints of the sun as the light passes through the Earth’s atmosphere.
“I can confirm this space fact,” tweeted Scott Kelly, to a recent Space fact Tweet. Kelly is a former NASA astronaut and a commander of the International Space Station.
More on the phenomenon
All wavelengths of visible light passing through Earth’s atmosphere are attenuated. This ensures the light reaching our eyes does not immediately saturate the eye’s cone receptors.
“This allows the brain to perceive color from the image with a little less blue-yellow. Though it does not affect what our eyes see, all x-ray and gamma-ray radiation are filtered out before it comes close to the ground. Most UV is absorbed by stratospheric ozone (above 10km) and most IR is absorbed by water vapor and other molecules with non-zero dipole moments,” explained NASA.
Additionally, NASA added that when sunlight passed through several atmospheres, sunsets, and sunrises, blue light gets scattered. Hence leads to a greater amount of blue light dispersion and allows red wavelength to enter. The sun is classified as a yellow dwarf star. However, it is a misnomer and only refers to its medium size.