An echelle spectrometer-spectrograph for astronomical use.

A compact echelle spectrometer-spectrograph has been designed for use at the Cassegrain focus of the University of Wisconsin 91-cm telescope at Pine Bluff. Laboratory results obtained with this instrument show that it has great potential for both stellar and nebular studies. Typical photographs and photoelectric scans of laboratory spectra are shown. A method of determining the profile of the echelle blaze is discussed. The instrument has high dispersion, 2.5 A/mm at 5000 A with a camera focal length of 0.5 m, and a spectral purity of 1.25 A/mm of entrance slit.