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==Types of Cepheids==

==Types of Cepheids==

Cepheid variables fall into one of two categories, Type I, also known as ''classical Cepheids'' or [[Delta Cepheid]] stars, and Type II, also known as [[W Virginis star]]s.  The Type I Cepheids are extreme [[Metallicity|population I stars]] located in the spiral arms of galaxies.  Metal rich and some 4 times as luminous as Type II Cepheids, these stars typically have a variation period lasting 5 to 10 days in lenght. Type II Cepheids on the other hand are [[Metallicity|metal-poor population II stars]].  Their periods of variability typically ranges from 10 to 30 days in length, and are primarily found in [[elliptical galaxy|elliptical galaxies]], [[globular cluster]]s, and galactic halos.<ref>http://adsabs.harvard.edu/abs/2002PASP..114..689W</ref>

Cepheid variables fall into one of two categories, Type I, also known as ''classical Cepheids'' or [[Delta Cepheid]] stars, and Type II, also known as [[W Virginis star]]s.  The Type I Cepheids are extreme [[Metallicity|population I stars]] located in the spiral arms of galaxies.  Metal rich and some 4 times as luminous as Type II Cepheids, these stars typically have a variation period lasting 5 to 10 days in length. Type II Cepheids on the other hand are [[Metallicity|metal-poor population II stars]].  Their periods of variability typically ranges from 10 to 30 days in length, and are primarily found in [[elliptical galaxy|elliptical galaxies]], [[globular cluster]]s, and galactic halos.<ref>http://adsabs.harvard.edu/abs/2002PASP..114..689W</ref>

== Sources ==

== Sources ==