<P> In astronomy , stellar classification is the classification of stars based on their spectral characteristics . Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with spectral lines . Each line indicates a particular chemical element or molecule , with the line strength indicating the abundance of that element . The strengths of the different spectral lines vary mainly due to the temperature of the photosphere , although in some cases there are true abundance differences . The spectral class of a star is a short code primarily summarizing the ionization state , giving an objective measure of the photosphere 's temperature . </P>
<P> In astronomy , stellar classification is the classification of stars based on their spectral characteristics . Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with spectral lines . Each line indicates a particular chemical element or molecule , with the line strength indicating the abundance of that element . The strengths of the different spectral lines vary mainly due to the temperature of the photosphere , although in some cases there are true abundance differences . The spectral class of a star is a short code primarily summarizing the ionization state , giving an objective measure of the photosphere 's temperature . </P>
the differences between the different spectral types of stars are primarily due to
the differences between the different spectral types of stars are primarily due to
ionization state
ionization state