Optical System of Chinese SONG Telescope

The paper reports optical system of a 1 meter diameter telescope dedicated to Stellar Observations Network Group (SONG) for the National Astronomical Observatories, CAS. SONG is an international cooperative project, Optimize the design for Asteroseismology purposes. According to the prototype of SONG, Chinese SONG telescope includes Cassegrain telescope, Nasmyth platform, Coude train, Coude focal plane, Shack-Hartmann wavefront sensor and spectrograph. The telescope will provide a field of view of 65 arcsec at the Nasmyth F/36.67 focus, 10 arcsec at the F/6 Coude focus. The rotating tertiary mirror directs the light to the two Nasmyth foci, one for Shack-Hartmann wavefront sensor, the other for Nasmyth platform and spectrograph.