The Large Binocular Telescope

Abstract

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 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 cophased imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65-meter telescope. Binocular imaging with two co-pointed prime focus cameras began in Fall 2007, and science observing continues routinely. We will describe the scientific results and technical challenges of monocular Gregorian focus observations starting in Spring 2008. Commissioning of the first Gregorian spectrometer (LUCIFER1) has been completed with a rigid secondary mirror, and science observations have begun in December 2009. The telescope uses two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors has been tested in Italy with the adaptive loop closed, and arrived at the telescope in February 2010. The first adaptive optics images were achieved on-sky in May 2010. The Direct Gregorian focus has been prepared for the arrival of the second Gregorian spectrometer (MODS1).