a) Precession, parallax, and proper-motion all cause changes in a star's equatorial coordinates with respect to time. Briefly describe the origin of each of these three effects and how each is unique and distinct. [6 marks] year), and a radial velocity of −12.0kms−1. Its apparent visual magnitude is 12.2. b) Calculate the distance to the star in parsecs and meters. [2 marks] c) Calculate the absolute magnitude of the star. [2 marks] d) Calculate the magnitude of velocity of the star with respect to the us. [4 marks] e) Explain why parallax and proper motion can be measured much more precisely from space. [2 marks]