Editing Planisphere (section)

{{Short description|Class of star chart}}
{{other|Planisphere (disambiguation)}}
[[File:Philips Planisphere.jpg|thumb|right|upright=1.3|Philips' Planisphere, ca. 1900]]

In [[astronomy]], a '''planisphere''' ({{IPAc-en|ˈ|p|l|eɪ|.|n|ɪ|ˌ|s|f|ɪər|,_|ˈ|p|l|æ|n|.|ɪ|-}}) is a [[star chart]] [[Analog computer|analog computing instrument]] in the form of two adjustable disks that rotate on a common pivot. It can be adjusted to display the visible stars for any time and date. It is an instrument to assist in learning how to recognize [[star]]s and [[constellation]]s. The [[astrolabe]], an instrument that has its origins in  [[Hellenistic astronomy]], is a predecessor of the modern planisphere.
The term ''planisphere'' contrasts with ''[[armillary sphere]]'', where the [[celestial sphere]] is represented by a three-dimensional framework of rings.