Aries is one of the constellations of the zodiac. It is located in the Northern Hemisphere between Pisces to the west and Taurus to the east. The name Aries is Latin for ram. It is one of the 48 constellations described by the 2nd century astronomer Ptolemy, and remains one of the 88 modern constellations defined by the International Astronomical Union. Aries is the first astrological sign in the Zodiac, spanning the first 30 degrees of celestial longitude, which area the Sun transits, on average, between March 21 to April 20 each year. Poeticon astronomicon is a star atlas whose authorship is disputed. The work was originally attributed to the Roman historian Gaius Julius Hyginus (64 BC - AD 17). The book lists most of the constellations in the same order as Ptolemy's Almagest (2nd century AD) which has led many to believe that a more recent Hyginus created the text. The Poeticon astronomicon was not formally published until 1482, by Erhard Ratdolt. He commissioned a series of woodcuts, but the relative positions of the stars bear little resemblance to the descriptions given by Hyginus in the text or the actual positions of the stars in the sky.