PLANISPHERE

[pla.ni.sphere] n [alter. of ME planisperie, fr. ML planisphaerium, fr. L planum plane + sphaera sphere] (1571): a representation of the circles of the sphere on a plane; esp: a polar projection of the celestial sphere and the stars on a plane with adjustable circles or other appendages for showing celestial phenomena for any given time -- pla.ni.spher.ic adj