A constellation representing the three-headed monster that guarded the gates of Hades, introduced by Johannes Hevelius in 1687. It is depicted as being grasped in the outstretched hand of Hercules, who overpowered Cerberus and dragged it from the Underworld to the surface as one of his labours.

Cerberus consisted of the four stars we now know as 93, 95, 102, and 109 Herculi (R. H. Allen wrongly states 96 Herculi to have been a member). Although, in mythology, Cerberus was supposedly a three-headed dog, Hevelius and all subsequent map makers illustrated it with three snake heads. Hevelius’s Cerberus replaced another figure, the branch from the tree of the golden apples, that Johann Bayer had previously depicted in the hand of Hercules. Bayer’s more elaborate figure consisted of 10 stars.


Cerberus held in the grasp of Hercules, as shown on the Firmamentum Sobiescianum star atlas of Johannes Hevelius (1690). It is drawn in mirror image, as it would appear on a celestial globe. Image courtesy ETH-Bibliothek Zurich.

In or around 1721 the English engraver John Senex, a friend of Edmond Halley, combined Cerberus with the apple branch, Ramus, to produce Cerberus et Ramus. This combined figure first appeared on Senex’s chart of the northern celestial hemisphere, Stellarum Fixarum Hemisphaerium Boreale, which he produced from Halley’s unauthorized edition of Flamsteed’s star catalogue. The serpents in this case were wrapped around the branch, and this is how it was subsequently shown on the Uranographia atlas of Johann Bode (see illustration below).


Cerberus et Ramus shown in the Uranographia of Johann Bode (1801).

© Ian Ridpath. All rights reserved