Context. A longstanding challenge for understanding classical Cepheids is the Cepheid mass discrepancy, where theoretical mass estimates using stellar evolution and stellar pulsation calculations have been found to differ by approximately 10-20%.
Aims: We study the role of pulsation-driven mass loss during the Cepheid stage of evolution as a possible solution to this mass discrepancy.
Methods: We computed stellar evolution models with a Cepheid mass-loss prescription and various amounts of convective core overshooting. The contribution of mass loss towards the mass discrepancy is determined using these models,
Results: Pulsation-driven mass loss is found to trap Cepheid evolution on the instability strip, allowing them to lose about 5 - 10% of their total mass when moderate convective core overshooting, an amount consistent with observations of other stars, is included in the stellar models.
Conclusions: We find that the combination of moderate convective core overshooting and pulsation-driven mass loss can solve the Cepheid mass discrepancy.
Astronomy and Astrophysics
- Pub Date:
- May 2011
- stars: mass-loss;
- stars: variables: Cepheids;
- stars: fundamental parameters;
- Astrophysics - Solar and Stellar Astrophysics
- 4 pages, 2 figures and 2 tables. Accepted for publication A&