The status of the 1.26 m infrared telescope and its photometer system. Progress and systems.

The preparatory work undertaken on the 1.26-m IR telescope at the Xinglong station of Beijing Astronomical Observatory since its installation in winter 1985 is reviewed. The instrument has a primary mirror of average thickness 80 mm and aperture-thickness ratio about 16; its total weight is 7 tons, and it employs a direct-drive worm-gear system. Particular attention is given to the tracking and position encoding systems, the pointing accuracy, the chopping secondary and 45-deg rotatable mirror, the InSb photometer, the low-resolution circular-variable-filter spectrometer, and the data-acquisition system. Diagrams and graphs are provided.