A Celestial Avatar is an avatar of a planetary or celestial body.
Avatars are the artificial constructs built by stellar bodies in order to travel, communicate, and to change and manipulate important events in history. An Avatars appearance usually reflects what its respective celestial body looks like, in either a superficial way, or by how the Avatar acts. They are extremely powerful creatures, and often change events on a universal scale. While they are immortal and can recover from most injuries, even fatal ones, avatars can be killed as shown when Dylan Hunt killed Virgil Vox with his force lance.
Appearance
Avatars usually assume a humanoid form, but are themed by whatever celestial body they represent. For example, Trance Gemini, the Avatar of the Vedran sun.