How rotation affects masses and ages of classical Cepheids

¹ Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD 21218, USA
² Départment d’Astronomie, Université de Genève, 1290 Sauverny, Switzerland
³ Astronomical Institute, Graduate School of Science, Tohoku University, Sendai, 980-8578 Miyagi, Japan

^* ria@jhu.edu

Published online: 8 September 2017

Abstract

Classical Cepheid variable stars are both sensitive astrophysical laboratories and accurate cosmic distance tracers. We have recently investigated how the evolutionary effects of rotation impact the properties of these important stars and here provide an accessible overview of some key elements as well as two important consequences. Firstly, rotation resolves the long-standing Cepheid mass discrepancy problem. Second, rotation increases main sequence lifetimes, i.e, Cepheids are approximately twice as old as previously thought. Finally, we highlight the importance of the short-period ends of Cepheid period distributions as indicators for model adequacy.