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K.A. Kluttz, R.O. Gray (Appalachian St. Univ.)
We have designed and constructed an economical medium-resolution spectrograph to be used on the 32-inch telescope of Appalachian State University's Dark Sky Observatory (DSO). The primary function of this instrument will be to study shell and emission-line stars. However, we will also use this instrument for chemical abundance studies and radial velocities.
The basic design is that of an Ebert spectrograph with a single 6-inch mirror acting as both the collimator and camera. The primary dispersion is accomplished by a reflection grating, and order separation is accomplished by a grism. The spectrograph has been designed so that three wavelength regions are simultaneously imaged on the CCD camera. When the H\alpha line is centered in the third order, H\beta and lines of Fe II multiplet 42 -- often enhanced in shell and emission-line stars -- appear in the fourth order and the fifth order contains both the Ca~II K & H lines. To facilitate abundance measurements, a telluric-free region near 6400Å\ is available in the third order by tilting the main diffraction grating.
Preliminary tests have shown that the resolution of the new spectrograph is 0.42Å\ in the third order (R \approx 15,000). This relatively high resolution will allow studies to be conducted at DSO which have not previously been possible with the instrumentation currently in use.
Several optical components for this spectrograph were purchased with grants from the Fund for Astrophysical Research and the University Research Council.
The author(s) of this abstract have provided an email address for comments about the abstract: kkluttz@yahoo.com
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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.