We describe a low-cost compact grism spectrometer for use with small astronomical telescopes. The system can be used with existing charge-coupled device (CCD) cameras and filter wheels. The optical design consists of two prisms, a transmission grating, a collimating lens, and a focusing lens, all enclosed in a 3D-printed housing. The system can be placed inline, typically in an unused filter wheel slot. Unlike conventional spectrometers, it does not require the target to be precisely positioned on a narrow slit. The mean resolving power ( 300) is sufficient to resolve the spectral lines of many astronomical objects discussed in undergraduate astronomy labs, such as stellar absorption lines along the main-sequence, emission lines of early type hot stars and galactic novae, and redshifts of bright quasars and supernovae.
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APPARATUS AND DEMONSTRATION NOTES| November 01 2017
A compact grism spectrometer for small optical telescopes
Dominic A. Ludovici;
Dominic A. Ludovici, Robert L. Mutel; A compact grism spectrometer for small optical telescopes. Am. J. Phys. 1 November 2017; 85 (11): 873–879. https://doi.org/10.1119/1.5000801
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