Interest world-wide in the provision of new observational astro­ nomical facilities in the form of ground-based optical telescopes of large aperture has never been higher than exists at present. The benefits to be gained from increased aperture size, however, are only utilised effectively if efficient instrumentation is also available. There have been significant improvements recently in this area, part­ icularly in detector technology and data handling as well as in optical design, so that systems which are currently being developed have the capability of being vastly more powerful in terms of the efficient use of photons than those which existed only 5 years ago. The rationale for the decision by Commission 9 of the International Astronomical Union to hold IAU Colloquium 67, therefore, was to obtain reports on these developments with the emphasis placed upon overall efficiency of the complete observational system - from telescope aperture right through to detector output. A fitting venue for the meeting was the site of the 6 metre BTA (Bolshoi Azimuth Telescope) at Zelenchukskaya in the Caucasus mount­ ains, USSR. The BTA is operated by the Special Astrophysical Observatory located at Nizhnij Arkhyz, a few kilometres from the telescope itself.

Inhalt

Section I: Optical Telescopes, Existing and Planned.- The Zelenchuk 6m Telescope (BTA) of the USSR Academy of Sciences.- Progress Report on the Performance of the Multiple Mirror Telescope.- The Canada-France-Hawaii Telescope.- Honeycomb Mirrors of Borosilicate Glass; Current Results and Plans for 7-8m Diameter.- Optical System for the University of Texas 7.6m Telescope.- A 6-metre Polar-viewing Telescope.- Design of the 4.2m Herschel Telescope and Instruments.- Improved Coudé Efficiency of Existing Telescopes.- Use of Large Telescopes in Fast Focal Ratio Mode - Application to the 6m Telescope (BTA).- A Coronographic Mode for Large Telescopes.- Aerodynamic and Thermal Problems Around and Inside a Dome and Telescope.- The Performance of Ground Based Telescopes.- Information Efficiencies of Telescopes and their Instrumentation.- Discussion.- Section II: Spectrographs and Spectrometers.- Multi-Order Formats to Increase the Versatility of Cassegrain Spectrographs.- Transit Telescope Designs Optimized for Multiple Object Spectroscopy with Fibers.- An Integral Field Spectrograph (IFS) for Large Telescopes.- Optical Designs of Plane Aspherized Grating Spectrographs.- Un Spectrographe à Réseau Asphérique pour Télescope f/4.- High Resolution Imagery and Slitless Spectroscopy at the Prime Focus of the CFH Telescope.- The Catadioptric Camera as Used for Astronomical Spectroscopy with Image Tubes and Similar Detectors: A Limited Review.- A Spectrophotometer Devoted to Stellar Seismology.- The 200-Channel Spectrometer of the Crimean Astrophysical Observatory.- A Photometric System to Search for Optical Variability on Time-scales of 3 × 10-7 to 300s: Main Results.- Discussion.- Session III: Interferometry.- Speckle Interferometry with the BTA Telescope.- Experiments in Differential Speckle Interferometry.- High Angular Resolution with Rotation Shearing Interferometers: Preliminary Results and Future Potentials.- A High Resolution Fourier Transform Spectrometer for the Cassegrain Focus at the CFH Telescope.- Two Dimensional Interferometric Photon Counting Observations with the 6m Telescope.- Measurements of Photon Statistics with Nanosecond Resolution.- Discussion.- Session IV: Detector Systems.- Solid State Imagers for Astronomy.- Recent Progress with Multi-Anode Microchannel Array Detector Systems.- Spectroscopy with Photon-Counting Reticons.- Experiments with Silicon Array Detectors in the RGO Coudé Spectrograph.- Two-Dimensional Television System: Application for Direct Acquisition of Images and Speckle Interferometry.- TV Spectrum Scanner of the 6-meter Telescope.- Utilisation des Récepteurs Electronographiques avec les Grands Télescopes.- Application of the Electronographic Image Converter for Spectroscopy at the 2.6m Reflector of the Crimean Astrophysical Observatory.- First Results with an Electronographic Camera Used at the Prime Focus of the C.F.H. Telescope in Hawaii.- Discussion.- Author Index.