GENERAL KNOWLEDGE

Detailed explanation-1: -When an object is moving away from us, the light from the object is known as redshift, and when an object is moving towards us, the light from the object is known as blueshift. Astronomers use redshift and blueshift to deduce how far an object is away from Earth, the concept is key to charting the universe’s expansion.

Detailed explanation-2: -If a star is traveling towards us, its light will appear blueshifted, and if it is traveling away the light will be redshifted. This shift in color will not change the apparent color of the star enough to be seen with the naked eye.

Detailed explanation-3: -If a star is moving towards the earth, its light is shifted to higher frequencies on the color spectrum (towards the green/blue/violet/ultraviolet/x-ray/gamma-ray end of the spectrum). A higher frequency shift is called a “blue shift".

Detailed explanation-4: -As objects move away from us, their light gets shifted into longer wavelengths or the red end of the spectrum-that’s redshift. Blueshift is the opposite, when light is shifted to shorter wavelengths on the blue side of the spectrum as an object comes towards us.