Blueshift is observed when(1 point)

Responses

a distant luminous object travels rapidly towards an observer.
a distant luminous object travels rapidly towards an observer.

a luminous object is stationary compared to an observer.
a luminous object is stationary compared to an observer.

a luminous object travels alongside an observer.
a luminous object travels alongside an observer.

a distant luminous object travels rapidly away from an observer.

Blueshift is observed when:

a distant luminous object travels rapidly towards an observer.