Blueshift is observed when
a
a luminous object is stationary compared to an observer.
b
a luminous object travels alongside an observer.
c
a distant luminous object travels rapidly towards an observer.
d
a distant luminous object travels rapidly away from an observer.
c
a distant luminous object travels rapidly towards an observer.
c
a distant luminous object travels rapidly towards an observer.
c
a distant luminous object travels rapidly towards an observer.
Blueshift is the phenomenon observed when light or other electromagnetic waves from a distant luminous object appear to have shorter wavelengths (shifted towards the blue end of the spectrum) compared to when the object is at rest relative to the observer. This occurs when the object is moving rapidly towards the observer.
To understand why blueshift occurs, we can use the concept of the Doppler effect. The Doppler effect states that when a source of waves (such as light) is moving relative to an observer, the wavelength of the waves will appear shorter if the source is moving towards the observer. This is because each successive wave is emitted from a position closer to the observer than the previous wave. As a result, the waves become compressed, leading to a shorter wavelength.
In the case of blueshift, if a distant luminous object is moving rapidly towards an observer, the light waves emitted by the object are compressed as they travel towards the observer. This compression causes a decrease in the wavelength of the light, making it shift towards the blue end of the electromagnetic spectrum.
Therefore, option c is the correct answer.