26cm High-Resolution Vaccum Solar Photospheric and Chromospheric Telescope at the Yunnan Observatory

A 26cm high-resolution vaccum solar photospheric and chromosphoeric telescope developed by the Nanjing Astronomical Factory and the Yunnan Observatory was installed at the Yunnan Observatory in early 1986 and put into operation in March 1989. It is a spar of double tubes with an aperture of 26cm each for observing the photospheric and chromospheric fine structures of active phenomena on the SunPerformance of the 26cm solar telescopePhotospheric tube Chromospheric tubeAperture 260mm 260mm Dimeter of solar image 300mm 85mm Field of view 3.8'×2.6' 7.3×6.0' Frame size 36×24mm 22×16mm Filter 5500±100Å6562.8Å, 0.46 Å/0.24Å, shift ±1.5Å Exposure time 1/500, 1/1000 sec. 1/20 sec.Spatial resolution 0.7 arcsec 1.2 arcsccTemporal resolution 1 sec. 5 sec.the scientific basis and brief history of the development of the telescope, its overall performance and optical system, and the main technical measures adopted for obtaining the high-resolution observations of the Sun arc described. The installation, adjustment and test observation of the telescope are also briefly described. Some work on the perfection and improvement of the performance of the telescope is being done, so that the telescope may play an active role in the research on flares during Cycle 22.