Anomalous Cepheids: origins

Anomalous Cepheids are pulsating stars with periods from 0.3 to ~2 days which pulsate in a fundamental mode and a first overtone. They were discovered in dwarf galaxies. The number of anomalous Cepheids in the Large and Small Magellanic Clouds, as well as in the Milky Way has significantly increased. There are still no anomalous Cepheids discovered in globular clusters. They follow a period-luminosity relation that is located close to the classical Cepheids relation, but with a shorter period. They are intermediate age star, 4-5 Gyrs, with low metallicity.