• (n.) The art of describing or delineating the stars; a description or mapping of the heavens.
As·trog'ra·phy noun [ Astro'cf + -graphy .] The art of describing or delineating the stars; a description or mapping of the heavens. 
Astrography was originally the science of describing the stars, the term is now applied to the science of mapping the heavens.
astrography The mapping of the heavens; the science of describing the stars.