Proper motion (5 marks) (a) The gure on the right shows the three A stars and their velocities. Which star has the largest proper motion? Which

Proper motion (5 marks) (a) The figure on the right shows the three Astars and their velocities. Which star has the largest proper motion? Which star ./has the smallest proper motion? (b) In Chapter 10 of the slides, on page 52, cthe position of a star changes over time. On page 56, the position of a star also ®changes over time. Yet the explanationsare different. How could we distinguish the two situations? [Note: For simplicity, let’s say that a change of position is due to either the propermotion or stellar parallax, but not both.]