When a star is brought into the field of view and the spectroscope is properly focused and adjusted, you will see a beautiful spectrum with the colors of the rainbow spread out along its length. Depending on the spectral type and luminosity class of the star, and your particular setup, you may see hydrogen lines cutting perpendicular across the spectrum, or many fine lines of metals, or wide absorption bands of molecules. These lines and bands in stellar spectra have been called the "fingerprints of the stars" because their patterns identify the elements in a star's atmosphere and indicate a star's temperature. These spectral features are easy to see in some classes of stars and more difficult to see in others.
The image below was taken with the Visual / Photo / CCD
The visibility of spectral features is dependent not only on the type of star being examined but also on the variables that most amateur astronomers are already familiar with: stellar magnitude, telescope aperture, seeing conditions, and the experience of the observer.
These spectroscopes are guaranteed to show hydrogen lines in the spectra of Vega and Sirius and molecular bands in the spectra of Betelgeuse and Antares.