Classical Cepheid Pulsation Models. X. The Period‐Age Relation

Citations Over TimeTop 10% of 2005 papers

Abstract

We present new Period-Age (PA) and Period-Age-Color (PAC) relations for fundamental and first overtone classical Cepheids. Current predictions rely on homogeneous sets of evolutionary and pulsation models covering a broad range of stellar masses and chemical compositions. We found that PA and PAC relations present a mild dependence upon metal content. Moreover, the use of different PA and PAC relation for fundamental and first overtone Cepheids improves the accuracy of age estimates in the short-period (log P = 1) range (young Cepheids), since they account for the position of individual objects inside the instability strip. We performed a detailed comparison between evolutionary and pulsation ages for a sizable sample of LMC (15) and SMC (12) clusters which host at least two Cepheids. In order to avoid deceptive uncertainties in the photometric absolute zero-point, we adopted the homogeneous set of B,V,I data for clusters and Cepheids collected by OGLE. We also adopted the same reddening scale. The different age estimates agree at the level of 20 % for LMC clusters and of 10 % for SMC clusters. We also performed the same comparison for two Galactic clusters (NGC6067, NGC7790) and the difference in age is smaller than 20 %. These findings support the use of PA and PAC relations to supply accurate estimates of individual stellar ages in the Galaxy and in external Galaxies. The main advantage of this approach is its independence from the distance.

Related Papers

• → Search for second overtone mode Cepheids in the Magellanic Clouds(1998)3 cited
• Nonlinear models of first overtone mode Cepheids(1993)
• → Search for second overtone mode Cepheids in Magellanic Clouds(2002)
• Non-Pulsating Stars in the R R Lyrae and Cepheid Instability Strips.(1973)
• → Nonlinear Convective Pulsation Models of Second Overtone SMC Cepheids(2002)