Caelus appears at the top of the cuirass
Caelus or Coelus was a god of the sky in Roman myth and theology and literature. Its name usually appears in masculine form when he is thought of as a male generative force.
According to Cicero and Hyginus, Caelus was the son of Aether and Dies ("Day" or "Daylight"). Caelus and Dies were in this tradition the parents of Mercury.