Hipparchus was an ancient Greek astronomer, mathematician, and geographer who lived around 190 to 120 BCE. He is often regarded as the father of astronomy due to his significant contributions, including the development of a star catalog that listed over 850 stars and the introduction of the concept of celestial coordinates. His work laid the foundation for future astronomical studies. In addition to his astronomical achievements, Hipparchus is known for creating the first known trigonometric table, which helped in calculating angles and distances in astronomy. His methods and observations influenced later astronomers, including Ptolemy, and shaped the course of Western astronomy for centuries.