Cepheid Mass-loss and the Pulsation -- Evolutionary Mass Discrepancy

Abstract

I investigate the discrepancy between the evolution and pulsation masses for Cepheid variables. A number of recent works have proposed that non-canonical mass-loss can account for the mass discrepancy. This mass-loss would be such that a 5Mo star loses approximately 20% of its mass by arriving at the Cepheid instability strip; a 14Mo star, none. Such findings would pose a serious challenge to our understanding of mass-loss. I revisit these results in light of the Padova stellar evolutionary models and find evolutionary masses are ($17\pm 5$)% greater than pulsation masses for Cepheids between 5<M/Mo<14. I find that mild internal mixing in the main-sequence progenitor of the Cepheid are able to account for this mass discrepancy.

15 pages, 3 figures, ApJ accepted

References in corpus (6)

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Cited by in corpus (2)

• Direct Detection of the Close Companion of Polaris with the Hubble Space Telescope
• On the Enhancement of Mass Loss in Cepheids Due to Radial Pulsation