What is the person who studies astrology called?

Astrology is the study of how events on earth correspond to the positions and movements of astronomical bodies(heavenly bodies). A horoscope is a diagram of the heavenly bodies showing the relative positions of the sun, moon, stars, and planets at a given time. This diagram is created through the study of astronomy. People who study astronomy are called Astrologers. So, it'll be safe to call people who study these horoscopes Astrologers. Hope this helps, thanks.