The Constellation Directory


"The Unicorn"


By IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg) [CC-BY-3.0], via Wikimedia Commons

Abbreviation: Mon
Genitive: Monocerotis
Constellation family: Orion
Nearest constellations: Canis Major, Canis Minor, Gemini, Hydra, Lepus, Orion, and Puppis
Right ascension: 7.15h
Declination: -5.74°
Visible between latitudes: +75° and -86°
Square degrees: 482
Luminary: Beta Monocerotis
Notable deep sky objects: M50, NGC 2237 (the Rosette Nebula), NGC 2264 (the Cone Nebula), the Snowflake Cluster, the Fox Fur Nebula


By Johannes Hevelius from Prodromus Astronomia - Volume III

By Johannes Hevelius [Public domain], via Wikimedia Commons

Monoceros is a faint constellation near the equator. It is best seen in February.

The brightest star in the constellation, Beta Monocerotis, is a unique triple star system. The three stars form a distinct triangle when viewed through a telescope.

Monoceros includes the location of Plaskett's star, which is one of the most massive binary stars discovered in the universe. The two stars have a combined mass of around 100 times the mass of the Sun and orbit a common center of gravity every 14.4 days.


There is no mythology associated with this constellation.