(n.) The use of the spectroscope; investigations made with the spectroscope.

astrogeology astrognosy astrography astrolithology astronomy astrophotography astrophysics celestial mechanics chromatics chromatography chromatology chromatoscopy colorimetry electron optics gravitational astronomy infrared spectroscopy meteoritics microscopics microscopy optical physics optics optometry photography radar astronomy radio astronomy solar physics spectrography spectrometry spectrophotometry spectrum analysis stargazing stellar photometry stereoscopy telescopy uranography uranology uranometry