Blueshift is observed when(1 point)%0D%0AResponses%0D%0A%0D%0Aa distant luminous object travels rapidly towards an observer%0D%0Aa distant luminous object travels rapidly towards an observer%0D%0A%0D%0Aa luminous object is stationary compared to an observer%0D%0Aa luminous object is stationary compared to an observer%0D%0A%0D%0Aa distant luminous object travels rapidly away from an observer%0D%0Aa distant luminous object travels rapidly away from an observer%0D%0A%0D%0Aa luminous object travels alongside an observer

Answer 1

Blueshift is observed when a distant luminous object travels rapidly towards an observer. This effect occurs due to the Doppler effect, where the wavelength of light is compressed (shifted to the blue end of the spectrum) as the source moves closer to the observer.