1911 Encyclopædia Britannica/Ursa Minor

URSA MINOR (“The Little Bear”), in astronomy, a constellation of the northern hemisphere, mentioned by Thales (7th century B.C.) and by Eudoxus and Aratus. By the Greeks it was sometimes named Cynosura (Gr. κυνός, dog’s; οὐρά, tail), alleging this to be one of the dogs of Callisto, who became Ursa major. The Phoenicians named it Phoenice, or the Phoenician constellation, possibly in allusion to the fact that the brightest star is a Ursae minoris or the pole-star, which being situated very close to the north pole is of incalculable service to navigators. Ptolemy catalogued 8 stars, Tycho Brahe 7 and Hevelius 12. α Ursae minoris, more generally known as the pole-star or Polaris, a star of the 2nd magnitude, describes a circle of 2° 25′ daily about the north pole; it has a 9th-magnitude companion, and is also a spectroscopic binary.