The Pulsation Mode of Polaris

Abstract

AbstractPolaris (α UMi) is the only classical Cepheid withHipparcosparallax determined to better than 10% (Feast & Catchpole 1997). The correct identification of its pulsation mode is therefore crucial for calibrating the Cepheid period–luminosity relation. We show that Polaris is an overtone pulsator. Our analysis confirms the finding of Feast & Catchpole, but is entirely independent of the distance estimation.