Constellation Horologium (Clock)

Horologium: IAU Constellation Map [150]


Horologium is an amorphous place in the sky with stars weaker than the 4th magnitude. It is located between Eridanus near the bright star Achernar and the similarly inconspicuous constellation Reticulum. The covered area is 249 square degrees and the center culminates around midnight on November 24th. For Central Europe it just comes up just a little over the southern horizon. [9, 15]

Data for constellation Horologium [150]
IAU NameHorologium
IAU GenitiveHorologii
IAU Abbr.Hor
English NameClock
Opposition13 November
Season (47° N)
Right Ascension02h 12m 49s … 04h 20m 18s
Declination-67° 02' 09" … -39° 38' 13"
Area249 deg2
Neighbours (N↻)Eri, Hyi, Ret, Dor, Cae

Deep-Sky Object Descriptions



The constellation belongs to the group of figures that represent mechanical instruments and were introduced by the French Lacaille in 1752. [7]


  • [7] «Der grosse Kosmos-Himmelsführer» von Ian Ridpath und Wil Tirion; Kosmos Verlag; ISBN 3-440-05787-9
  • [9] «Drehbare Sternkarte SIRIUS» von H. Suter-Haug; Hallwag-Verlag, Bern
  • [15] «Hartung's Astronomical Objects for Southern Telescopes» by David Malin and David J. Frew; Melbourne University Press 1995; ISBN 0-522-84553-3
  • [150] IAU: The Constellations, 11. Oktober 2020;