planisphere
noun
pla·ni·sphere ˈplā-nə-ˌsfir 
: a representation of the circles of the sphere on a plane
especially : 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
planispheric
ˌplā-nə-ˈsfir-ik -ˈsfer-
adjective -ˈsfer- 
Example Sentences
Recent Examples on the Web Monthly sky maps take the place of a planisphere in this atlas, which covers both the northern and southern hemisphere. 
Popular Science, 13 Sep. 2019 Kids can craft their own planispheres and play games about the night sky. Sara Cagle, Los Angeles Times, 31 July 2019
Popular Science, 13 Sep. 2019 Kids can craft their own planispheres and play games about the night sky. Sara Cagle, Los Angeles Times, 31 July 2019 Word History
Etymology
alteration of Middle English planisperie, from Medieval Latin planisphaerium, from Latin planum plane + sphaera sphere
First Known Use
14th century, in the meaning defined above