5.3 Star Types and Reading Spectra

One way we can identify the type of a star is by looking at its spectrum, the amount of light it emits at each wavelength.  Each star's spectrum gives us all the information we have about that star. Although each star's spectrum is unique in detail, the shape of this spectrum histogram is similar to other stars of the same type. By comparing an unknown star's spectrum with the spectra of stars whose type is known, we can get clues to the mystery star's type. 

(put a CV spectrum somewhere on this page.)

You can find out more about the different natures of the four types of  stars I've observed by taking a look at the star type handout page.   Then, look the spectrum example for each type of star, using the links below. A new window will appear- keep using it for the rest of this session.

Star Types

White Dwarf Cataclysmic Variable Early Type Late Type

For each spectrum, notice the different shapes.  Answer these questions, and the information in your notebook, for future reference. 

  1. Notice the numbers on the x-axis  (the horizontal line). What is the range of the numbers? 

  2. What is the unit of measurement? 

  3. Find the same units of measurement on the diagram of the Electromagnetic Spectrum and compare the numbers from the star's spectra with these numbers.  What type of light is it showing you? 

  4. What is the range of intensities shown on the y axis (vertical)?

Go to the Next page to get started identifying.

Back to the sky map View all  sections of Rainbows and Spectra On to do star type ID's

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