in the sky at far northern latitudes to be of use in navigation. In Chinese astronomy, the main stars of Ursa Minor are divided between two asterisms: 勾陳 Gòuchén (Curved Array) (including α UMi, δ UMi, ε UMi, ζ UMi, η UMi, θ UMi, λ UMi) and 北極 Běijí (Northern Pole) (including β UMi and γ UMi). Characteristics Ursa Minor is bordered by Camelopardalis to the west, Draco to the west, and Cepheus to the east. Covering 256 square degrees, it ranks 56th of the 88 constellations in size. Ursa Minor is colloquially known in the US as the Little Dipper because its seven brightest stars seem to form the shape of a dipper (ladle or scoop). The star at the end of the dipper handle is Polaris. Polaris can also be found by following a line through the two stars—Alpha and Beta Ursae Majoris, popularly called the Pointers—that form the end of the "bowl" of the Big Dipper, for 30 degrees (three upright fists at arms' length) across the night sky. The four stars constituting the bowl of the Little Dipper are of second, third, fourth, and fifth magnitudes, respectively, and provide an easy guide to determining what magnitude stars are visible, useful for city dwellers or testing one's eyesight. The three-letter abbreviation for the constellation, as adopted by the IAU (International Astronomical Union) in 1922, is "UMi". The official constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of 22 segments (illustrated in infobox). In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates range from the north celestial pole to 65.40° in the south. Its position in the far northern celestial hemisphere means that the whole constellation is visible only to observers in the northern hemisphere. Features Stars The German cartographer Johann Bayer used the Greek letters alpha to theta to label the most prominent stars in the constellation, while his countryman Johann Elert Bode subsequently added iota through phi. Only lambda and pi remain in use, likely because of their proximity to the north celestial pole. Within the constellation's borders, there are 39 stars brighter than or equal to apparent magnitude 6.5. Marking the Little Bear's tail, Polaris, or Alpha Ursae Minoris, is the brightest star in the constellation, varying between apparent magnitudes 1.97 and 2.00 over a period