Planisphere
Class of star chart / From Wikipedia, the free encyclopedia
For the John Ashbery book, see Planisphere (book). For the tetralogy of songs by Justice, see Justice discography.
In astronomy, a planisphere (/ˈpleɪ.nɪˌsfɪər, ˈplæn.ɪ-/) is a star chart 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 stars and constellations. 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.
This article needs additional citations for verification. (June 2008) |