Faint Object Spectrograph and Camera for 1m Telescope

A Faint Object Spectrograph and Camera (FOSC)for 1-meter telescope in Yunnan Observatory is introduced in this paper.It is a focal reduced camera type instrument and is mounted at the Cassegrain focus of 1-m telescope in Yunnan Observatory.The FOSC can be used in four different modes:direct imaging, long slit spectroscopy, slitless spectroscopy and coronography, and it is efficient and flexible.The optics design for the camera and for the spectrograph are shown.The light from the f/13.3 Cassegrain focus of the 1-m telescope is collimated by collimating lens then passes to the camera and images on the CCD detector.In the wavelegth range of 404.6nm -766.5nm, the image quality is 0.5"in diameter which encircles 80% of the energy in the 10'of the field.Four modes are as follows:1 　Direct Imaging:It is a focal reduced camera with a field of 10'.The focal ratio is f/7. The standard filters of B、V、R、I are mounted for selection. 2 Slitless Spectroscopy Mode:A direct vision prism is inserted into the parallel beam of the focal reduced camera to become a slitless spectroscopy.The dispersion of this slitless spectroscopy is 100nm/mm in 486.1 nm. 3 Long Slit Spectroscopy:The long slits are available to do spectroscopy with the direct vision prism.There are three slits mounted on a wheel in the Cassegrain focus.The slit size is 40mm×65μm (～1"), 40mm ×100μm (～1.5"), 40mm ×150μm (～2.25"), respectively. 4 Coronography Mode:A special plate is mounted on the slits wheel which is in the area of Cassegrain focus.The coronograph image can be obtained and the faint nebulosity around bright objects would be imaged with this mode.