The Large Binocular Telescope

The Large Binocular Telescope (LBT) Observatory is a collaboration between institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio and Virginia. The telescope on Mt. Graham in Southeastern Arizona uses two 8.4-meter diameter primary mirrors mounted side-by-side to produce a collecting area equivalent to an 11.8-meter circular aperture. A unique feature of LBT is that the light from the two primary mirrors can be combined to produce phased array imaging of an extended. field. This coherent imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65-meter telescope. We will describe the scientific results and technical challenges of monocular prime focus imaging starting in Fall 2006. Binocular imaging with two co-pointed prime focus cameras began in Fall. 2007. Installation of a rigid (non-adaptive) secondary mirror occurred in Spring 2008 in time for the arrival of the first Gregorian spectrometer. The telescope will use two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors is now being tested in Italy, and is planned to be at the telescope by Summer 2009.