The Large Binocular Telescope (LBT) is an optical telescope for astronomy located on 10,700-foot (3,300 m) Mount Graham, in the Pinaleno Mountains of southeastern Arizona, United States. It is a part of the Mount Graham International Observatory.
LBT perched on an Arizona mountain
Dome during the day with doors closed
Interior looking down one of the primary mirrors
A segmented mirror is an array of smaller mirrors designed to act as segments of a single large curved mirror. The segments can be either spherical or asymmetric. They are used as objectives for large reflecting telescopes. To function, all the mirror segments have to be polished to a precise shape and actively aligned by a computer-controlled active optics system using actuators built into the mirror support cell.
Early segmented mirror, built out of 61 hexagonal segments in 1952.
The Keck II telescope showing the segmented primary mirror
Mirror segments made of beryllium