About

Monoceros (Greek: Μονόκερως, "unicorn") is a faint constellation on the celestial equator. Its definition is attributed to the 17th-century cartographer Petrus Plancius. It is bordered by Orion to the west, Gemini to the north, Canis Major to the south, and Hydra to the east. Other bordering constellations include Canis Minor, Lepus, and Puppis.

History and mythology

In Western astronomy, Monoceros is a relatively modern constellation, not one of Ptolemy's 48 in the Almagest. Its first certain appearance was on a globe created by the cartographer Petrus Plancius in 1612 or 1613 and it was later charted by German astronomer Jakob Bartsch as Unicornu on his star chart of 1624. German astronomers Heinrich Wilhelm Olbers and Ludwig Ideler indicate (according to Richard Hinckley Allen's allegations) that the constellation may be older, quoting an astrological work from 1564 that mentioned "the second horse between the Twins and the Crab has many stars, but not very bright"; these references may ultimately be due to the 13th century Scotsman Michael Scot, but refer to a horse and not a unicorn, and its position does not quite match. Joseph Scaliger (died 1609) is reported to have found Monoceros on an ancient Persian sphere. Astronomer Camille Flammarion (died 1925) believed that a former constellation, Neper (the "Auger"), occupied the part of that sky now deemed Monoceros and Microscopium, but this is disputed. Chinese asterisms Sze Fūh, the Four Great Canals; Kwan Kew; and Wae Choo, the Outer Kitchen, all lay within the boundaries of Monoceros.