Apparition

Ap·pa·ri·tion

The act of becoming visible; appearance; visibility.
The sudden apparition of the Spaniards.
— Prescott.

The apparition of Lawyer Clippurse occasioned much speculation in that portion of the world.
— Sir W. Scott.
The thing appearing; a visible object; a form.
Which apparition, it seems, was you.
— Tatler.
An unexpected, wonderful, or preternatural appearance; a ghost; a specter; a phantom.
I think it is the weakness of mine eyes That shapes this monstrous apparition.
— Shak.
The first appearance of a star or other luminary after having been invisible or obscured; -- opposed to occultation. (Astron.)