Spectra of stars reveal ions of elements and molecules through absorption and emission lines.   Identifying characteristics of a star's spectra depend on the surface temperature of the star and the elements and molecules present in the outer regions of the star.  At Yerkes Observatory we have mounted a small Objective Prism Telescope onto the 24 inch telescope in order to take spectra of stars and nebulae.  

Here are some examples of spectra images we have taken.  You can use the HOU-IP, Data Tools, Slice tool to draw a line through the spectra and plot the absorption and emission lines that may be present in the star. 

Vega is a white star.  Using our OPT system, Vega's spectrum looks like this:

Antares is a red star.  Using our OPT system, Antares' spectrum looks like this:

Now look at the spectra of Scheat and Altair.  Which star is more like cooler red Antares?

Which star is more like hotter white Vega?

Other spectra plots of from the Objective Prism Telescope.