A

David

Darling

long-period variable

The term 'long-period variable' is usually taken to be another name for a Mira star. There is no Cepheid-type period-luminosity law and indeed the periods and the amplitudes are not constant. In the past, the term was applied more generally to mean any red giant or supergiant pulsating variable with a period of 20 to 1,000 days, including, in addition to Mira variables, semi-regular variables and slow irregular variables. Long-period blue variables are pulsating B stars with periods longer than one day and amplitudes generally less than 0.05 magnitude but occasionally up to 0.1 magnitude.