Planisphere Biography, Planisphere Videos, Planisphere Similar artist, Planisphere Discography, Planisphere Tags
You are in : HOME : P : Planisphere :Biography Planisphere
A planisphere is a star chart analog computer that can be adjusted to
display the stars for any time and date. It is an instrument to learn how
to recognize stars and constellations. The astrolabe is a predecessor of
the modern planisphere. That instrument was known to the ancient Greeks.
It consists of a circular chart attached at its center to an opaque
overlay that has a clear roundish window or hole. The chart is mounted so
that it is free to rotate about the pivot point at the center. The star
chart contains all stars, constellations and (possibly) deep-sky objects
that are visible from a certain area on Earth. That area is a band around
the Earth centered on a certain (design) latitude. Since the night sky that
one sees from the Earth depends on the observer's latitude, planisphere
windows are designed for particular latitudes and one should choose the
latitude that is the closest match. Times are marked on the rims of the
overlay (e.g., 1
