The Constellation Directory


"The Clock"


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

Abbreviation: Hor
Genitive: Horologii
Constellation family: Lacaille
Nearest constellations: Caelum, Dorado, Eridanus, Hydrus, and Reticulum
Right ascension: 3.11h
Declination: -52.80°
Visible between latitudes: +20° and -90°
Square degrees: 249
Luminary: Alpha Horologii
Notable deep sky objects: Horologium Supercluster


Horologium is a constellation in the Southern Hemisphere. It is best seen in December.

Horologium was created in the mid-1700s by Nicolas Louis de Lacaille. He originally named it Horologium Oscillitorium in honor of the pendulum clock which was invented by Christiaan Huygens in the previous century.

This constellation contains the Horologium Supercluster (also called the Horologium-Reticulum Supercluster) which is a massive cluster of galaxies 550 million light years in length. It is the largest supercluster within 1 billion light years.


There is no mythology associated with this constellation.