Each element composing an object releases an electromagnetic wave of a specific frequency. Utilizing this property, it is possible to determine the elemental composition of a star by classifying and analyzing the wavelength of each light it emits. This is the principle of a visible light spectrograph (spectral analysis).

On NAYUTA, a spectroscope attached to the Nasmyth focus effectively analyzes the chemical composition of remote stars. Analyzing the hydrogen atoms of a comet, for instance, can reveal its origin.