<title>Large Binocular Telescope</title>

Abstract

The Lange Binocular Telescope (LBT) Project is an international collaboration among US, German and Italian Astronomical Institutes to build a binocular telescope with two 8.4 m primary mirrors. The LBT will have a collecting area equivalent to that of a 1 1 .8 m single dish telescope, and an angular resolution, when the two mirror are co-phased, equivalent to that of a 22.8 m telescope. The construction of the Large Binocular Telescope is in progress on all aspects. The first of the two honeycomb primary mirrors is being prepared for polishing, while the preparation of the casting of the blank for mirror two is in progress at the Mirror Lab of the University of Arizona. The structure of the enclosure is completed on Mt. Graham (AZ) and telescope pre-erection is about to start in the Ansaldo factory in Milan (Italy). Operations will start in 2002 with one of the two primary mirrors while the telescope will operate with both mirrors from 2004. The initial instrumentation will consist of four types of instruments: - twin optical spectrograph located at the direct Gregorian foci, - twin wide field optical imagers at the prime foci, - twin near infrared spectrograph/imagers at the front bent Gregorian foci, - two different interferometers, one for optical and MR wavelengths and one for near/mid infrared at the central combined foci. The twin infrared instruments and the interferometers will be designed to fully exploit the adaptive correction provided by the adaptive secondary mirrors of the telescope.