If a star was moving in the same direction as Earth at the same speed, we would expect to see a blueshift in its spectrum.

Here's why:

* Doppler Effect: The Doppler effect is the change in frequency of a wave (like light) as the source and observer move relative to each other.

* Moving Towards: When a source of light is moving towards an observer, the light waves are compressed, resulting in a higher frequency (blueshift).

* Moving Away: When a source of light is moving away from an observer, the light waves are stretched, resulting in a lower frequency (redshift).

Since the star and Earth are moving in the same direction at the same speed, the relative velocity between them is zero. However, this is only true in the direction of motion. If we consider the light emitted from the star in the direction perpendicular to the motion of the Earth and the star, we will see a blueshift. This is because the light waves are emitted from a source that is moving towards the Earth.

It's important to note that the magnitude of the blueshift would be relatively small in this scenario, as the speed of Earth is relatively slow compared to the speed of light.