Editing Variable star (section)

=====Semiregular variables=====
{{Main|Semiregular variable}}

These are [[red giants]] or [[red supergiant|supergiants]]. Semiregular variables may show a definite period on occasion, but more often show less well-defined variations that can sometimes be resolved into multiple periods. A well-known example of a semiregular variable is [[Betelgeuse]], which varies from about magnitudes +0.2 to +1.2 (a factor 2.5 change in luminosity). At least some of the semi-regular variables are very closely related to Mira variables, possibly the only difference being pulsating in a different harmonic.