These pulsating horizontal-branch stars are known as RR Lyrae variable stars and they are obviously variable in brightness with periods of up to 1.2 days
variable valve timing | Variable (programming) | Variable valve timing | Variable surface glycoprotein | variable star | variable (programming) | Variable-message sign | variable-message sign | Variable-length code | Variable-incidence wing | Variable Hawk | Variable Geometry | Variable geometry | Variable elimination | Variable data printing | Variable cost | Variable capacitor | Variable bitrate | Variable Assembly Language | variable | RR Lyrae variable | New Zealand's bush is variable in appearance, but generally the term connotates densely forested areas, like this one around Lake Gunn | metasyntactic variable | Local hidden variable theory | Limited dependent variable | Green's function for the three-variable Laplace equation | ''dependent'' or ''response'' variable | Cataclysmic variable star | American Association of Variable Star Observers |