Beta Cephei variables, also known as
Beta Canis Majoris stars, are
variable stars that exhibit small rapid variations in their brightness due to pulsations of the stars' surfaces, thought due to the unusual properties of iron at temperatures of 200,000
K in their interiors. These stars are usually hot blue-white stars of spectral class B and should not be confused with
Cepheid variables, which are named after
Delta Cephei and are luminous supergiant stars.