There is little known about the early life of Hipparchus other than the fact that he was born in Nicaea, Bithynia, now Iznik, Turkey in 190 B.C.. Hipparchus was the most important Greek astronomer of his time. The fact that he was extremely accurate in his research, helped his works gain credence. His accuracy is rather amazing since he used the only astronomical instrument available to him, his eyes. With his eyes he took on the task of measuring the positions of the stars and planets as they passed overhead each night, making a star chart as he went along. By the time he was done he had a catalog of 1,080 stars, which he had labled either, "bright", or "small". His research influenced the thinking of many great astronomers for many years after his death.

By comparing his own studies with those of earlier astronomers, Hipparchus discovered the precession of the equinoxes, as well as many other things. His connection to Sun research is his calculation of the length of the year measured by the Sun. His calculation was within 6.5 minutes of modern measurements. He figured this out entirely without the aid of modern technology, which is quite amazing. Hipparchus also made a table of trigonometric chords that became the basis for what is now called trigonometry.