planisphere

noun

1. a map of half or more of the celestial sphere with a device for indicating the part of a given location visible at a given time.
2. a projection or representation of the whole or a part of a sphere on a plane.

noun

1. a projection or representation of all or part of a sphere on a plane surface, such as a polar projection of the celestial sphere onto a chart

n.late 14c., from Medieval Latin planisphaerium, from Latin planus (see plane (n.1)) + sphaera (see sphere (n.)).