ABSTRACT
The Hamilton Echelle Spectrometer, installed at the coude focus of the Shane 3-m telescope, is a high-dispersion spectrograph optimized for use with today's largest available CCDs, and for the even larger CCDs expected in the future. It was designed primarily for high-resolution (R = 30,000 to 60,000) wide-bandpass spectroscopy of point-like sources down to a limiting magnitude of about V = 16.5, over the 0.34- to 1.1 -micron spectral region. Its design differs from many conventional echelle spectrographs in several areas. The most important differences are its relatively large collimated beam size, the use of prisms rather than gratings for cross dispersion, minimum order separation, the use of protected silver mirror coatings throughout the system, and a fast (f/1.67) folder Schmidt camera with a flat external focal plane. Together, these features yield a very powerful spectrometer for high-resolution stellar spectroscopy. This paper describes the Hamilton spectrograph and discusses the philosophy behind its design. Several examples of the performance of the system are given.