What's the name of ancient officials' fortune telling?

What was the name of the fortune teller in the ancient palace?

Tian Jian, official name. The central organization responsible for observing astronomy, calculating calendars and managing astronomical phenomena in the early Yuan Dynasty. Later, the school of astronomy. There was a supervisor in the Jin Dynasty, who was in charge of astronomical events and taught students. Set up points, supervisors, less supervisors, judges, professors and supervisors. Jurisdiction over astronomy, calendar, three types, experiments and omissions. At the beginning of the yuan dynasty, due to the gold system, the company set up a rooftop, which was supervised by the secretary.