Observations of stars, planets and constellations were made by scholars of Ancient Egypt -- and they were so precise that they remained state of the art for two millennia.
Claudius Ptolemaeus, the geographer and astronomer from Ancient Egypt's Roman Period (who is more commonly known as Ptolemy), created a star catalogue, called the Almagest around 137 CE. The catalogue lists some 1028 stars, visible to the naked eye, associated with 48 different constellations (which date at least to the third century BCE works of Aratus and Eudoxus).
Each of the stars is identified both by constellation and position, given by ecliptic coordinates of latitude and longitude exact to a sixth of a degree. They are also recorded a corresponding magnitude (of brightness) on a scale of one to six. Ptolemy wrote that 'we observed as many stars as we could sight down to the sixth magnitude'1.
There is much debate whether Ptolemy originated the observations used in the Almagest, with detractors claiming that errors in longitude, and the fact that a few of the stars referenced would not have been visible above the horizon at Alexandria, where Ptolemy worked. It is possible that some of the work is based on that of Hipparchus, a Greek scholar working between 147 and 127 BCE in Rhodes (and six degrees further north than Alexandria which accounts for those stars otherwise hidden beneath the horizon).
The original of Ptolemy's Almagest is lost in history, but copies dating from the ninth to sixteenth century CE survive. An English translation of the work by Peters and Knobel, Ptolemy's Catalogue of Stars: A Revision of the Almagest, became a standard Astronomical reference when it was published in 1915 by the Carnegie Institute of Washington.
References
1 JB Hearnshaw, The Measurement of Starlight: Two centuries of Astronomical Photometry, Cambridge University Press, 1996.
