If we observe one edge of a star to be redshifted and the opposite edge to be blueshifted,what can we conclude about the star?
A)We must actually be observing planets orbiting the star in opposite directions,not the star planet itself.
B)The star is rotating.
C)The star is in the process of falling apart.
D)The star is in the process of formation.

Question

Quizplus · Accepted Answer

If one edge of a star is redshifted and the opposite edge is blueshifted, it indicates that the star is rotating. This is because the light emitted from the edge rotating towards us will be blueshifted, while the light emitted from the edge rotating away from us will be redshifted. Therefore, we can conclude that the star is not falling apart or in the process of formation, and it is unlikely to be planets orbiting in opposite directions.

If We Observe One Edge of a Star to Be