Figure 19-16: R I V U X G
Mira—A Long-Period Variable Star Mira, or ο (omicron) Ceti, is a variable star whose luminosity varies with a 332-day period. Luminosity variations are due to changes in both surface temperature and radius. At its dimmest, as in (a) (photographed in December 1961), Mira is less than 1% as bright as when it is at maximum, as in (b) (January 1965). The physical size of the star is too small to discern with the telescope used, but variations in brightness change how wide it appears in the image.
Mira—A Long-Period Variable Star Mira, or ο (omicron) Ceti, is a variable star whose luminosity varies with a 332-day period. Luminosity variations are due to changes in both surface temperature and radius. At its dimmest, as in (a) (photographed in December 1961), Mira is less than 1% as bright as when it is at maximum, as in (b) (January 1965). The physical size of the star is too small to discern with the telescope used, but variations in brightness change how wide it appears in the image.
(Lowell Observatory)