The statement that spectral lines of stars are all shifted toward the blue end of the spectrum is incorrect. It's the opposite that's true for most stars: the spectral lines are shifted towards the red end of the spectrum. This is due to the Doppler effect.

Here's why:

* The Doppler Effect: This principle states that the frequency of a wave (like light) changes depending on whether the source of the wave is moving towards or away from the observer. If the source is moving towards the observer, the waves are compressed, resulting in a higher frequency (shifted towards blue). If the source is moving away from the observer, the waves are stretched, resulting in a lower frequency (shifted towards red).

* Expanding Universe: Most stars in the universe are moving away from us due to the expansion of the universe. This means their light is stretched, causing a redshift.

* Exceptions: While most stars show a redshift, some nearby stars are actually moving towards us due to their individual motion within the Milky Way. These stars will exhibit a blueshift.

In summary:

* The spectral lines of most stars are shifted towards the red end of the spectrum due to the redshift caused by the expansion of the universe.

* A small number of stars show a blueshift because they are moving towards us.