Matthew 2:2 and 9 report that magi saw a star and followed it in their quest to find the birthplace of the King of the Jews. Here are a couple of paragraphs that helped me get a better grasp of what they were doing:
“The old Polynesians were great navigators. They took bearings by the sun by day and the stars by night. Their knowledge of the heavenly bodies was astonishing. They knew the earth was round, and they had names for such conceptions as the Equator and the northern and Southern tropics. . . . The Polynesians knew five planets, which they called wandering stars and distinguished them from the fixed stars, for which they had nearly two hundred different names. A good navigator in old Polynesia knew well in what part of the sky the different stars would rise and where they would be at different times of the night and at different times of the year. They knew which stars culminated over the different islands, and there were cases in which an island was named after a star which culminated over it night after night and year after year.
Apart from the fact that the starry sky lay like a glittering giant compass revolving from east to west they understood that the different stars right over their heads always showed how far north or south they were. When the Polynesians had explored and brought under their sway their present domain, which is the whole of the sea nearest to America, they maintained traffic between some of the islands for many generations to come. Historical traditions relate that, when the chiefs from Tahiti visited Hawaii, which lay more than 2,000 sea miles farther north and several degrees farther west, the helmsman steered first due north by sun and stars, till the stars above their heads told them that they were en the latitude of Hawaii. Then they turned at a right angle and steered due west till they came so near that birds and clouds told them where the group of islands lay.” (Heyerdahl, Thor. Kon-Tiki: Across The Pacific By Raft. New York: Pocket Books, 1984.)
