Medieval Islamic astronomers gave Arabic names to many stars that are still used today and they invented numerous astronomical instruments that could compute the positions of the stars . They built the first large observatory research institutes , mainly for the purpose of producing Zij star catalogues . Among these , the Book of Fixed Stars ( 964 ) was written by the Persian astronomer Abd al @-@ Rahman al @-@ Sufi , who observed a number of stars , star clusters ( including the Omicron Velorum and Brocchi 's Clusters ) and galaxies ( including the Andromeda Galaxy ) . According to A. Zahoor , in the 11th century , the Persian polymath scholar Abu Rayhan Biruni described the Milky Way galaxy as a multitude of fragments having the properties of nebulous stars , and also gave the latitudes of various stars during a lunar eclipse in 1019 .