Constellation Caelum (Engraving Tool)

Caelum: IAU Constellation Map [150]


Caelum is an inconspicuous, almost insignificant constellation at the end of Eridanus, southwest of Canis Maior and does not contain any stars brighter than 4.5 mag. It has an area of 125 square degrees and culminates at midnight on around November 30th. In Central Europe, it only just comes over the southern horizon. [9, 15]

Data for constellation Caelum [150]
IAU NameCaelum
IAU GenitiveCaeli
IAU Abbr.Cae
English NameEngraving Tool
Opposition2 December
Season (47° N)October … January
Right Ascension04h 19m 32s … 05h 05m 01s
Declination-48° 44' 18" … -27° 01' 30"
Area125 deg2
Neighbours (N↻)Lep, Eri, Hor, Dor, Pic, Col

Deep-Sky Object Descriptions



The constellation was introduced around 1752 by French astronomer Abbé Nicolas Louis de Lacaille, who lacked a little imagination. While all sorts of legendary heroes cavort in the constellations of the northern hemisphere, those in the southern hemisphere are more like the contents of a toolbox. The Caelum represents an engraving tool or burin, which was used by artisans to work on metal and ivory. [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;