FanCam—A Near-Infrared Camera for the Fan Mountain Observatory

摘要

The Fan Mountain Near-Infrared Camera (FanCam) provides the University of Virginia's 31 inch telescope with a near-infrared observing capability that is relatively unique among small-aperture telescopes. FanCam features an 8.7' × 8.7' field of view on a 1024 × 1024 Teledyne Imaging Sensors HAWAII-1 detector array. The instrument mounts at the f/15.5 focus of the 31 inch telescope. Its seeing-limited optical design, optimized for the JHK atmospheric bands, includes a field stop at the telescope focus, a doublet collimator, two eight-position filterwheels straddling a Lyot stop, and a doublet reimager. Four fold mirrors wrap the optical path onto a compact optical bench. The 0.51" pixel~(-1) plate scale leads to a slightly oversampled point spread function for the typical seeing of 1.5". The entire optical train is encased in a cryogenic dewar cooled by a closed-loop cooling system. This paper describes the optical, mechanical, cryogenic, and electronic design of the camera as well as some early results that illustrate the camera's capabilities.