The second mirror in a reflecting telescope (after the primary mirror), usually either convex, to reflect the image out of a hole in the bottom of the telescope to the Cassegrain focus or along the telescope mount axis to the coudé focus; or flat, to reflect the image out of the side of the telescope to the Newtonian focus.
A small mirror user to direct the incoming image from the primary system to the eyepiece in an optical system.
In a two-mirror reflecting telescope, the secondary mirror sits in front of the larger primary mirror and reflects light to the point at which it will be detected and recorded by an instrument. In simple telescopes, the secondary mirror is flat and bounces the light out the side of the tube to an eyepiece. In more complex and larger telescopes, it is convex and reflects light through a hole in the primary mirror.
In a reflecting telescope, a small mirror mounted in the beam of radiation that strikes the primary mirror, and from which radiation is reflected and brought to a focus.
A small mirror in a reflecting telescope that redirects light from the larger primary mirror toward the light-sensitive scientific instruments. In a Cassegrain-type telescope like the Hubble Space Telescope, the secondary mirror is slightly convex and directs light from the primary mirror back through a hole in the center of the primary mirror. Hubble's secondary mirror measures 12.2 inches (0.3 meters) in diameter.
A secondary mirror (or secondary) is a second light gathering and focusing surface in a reflector telescope. Light gathered by the primary mirror is directed towards a focal point typically past the location of the secondary. The secondary directs the light either out a side opening of the tube (Newtonian reflector) or back towards a focal point behind and through the primary (Cassegrain reflector)...