Capricornus, the sea goat, is a zodiacal constellation and one of the 48 constellations cataloged by Ptolemy in the 2nd century. It is located on the ecliptic between Sagittarius and Aquarius, and is south of the Summer Triangle and the Great square of Pegasus. Capricornus reaches its highest nightfall ascension in October. Its alpha star, Deneb Algedi (Delta Capricorni), is just brighter than magnitude 3, and can be seen under most reasonable conditions. The remainder of the constellation is rather dim and difficult to see in light-polluted urban skies. The globular star cluster, M30, is the only Messier object in this constellation.
© James R. Johnson, 2014.