Bump Cepheids

 

Together with Dr. Peter Wood, I have utilized non-linear pulsation models to reproduce the light and colour curves of bump Cepheids from the Large and Small Magellanic Clouds. This analysis now incorporates convection and turbulent eddy viscosity. The light curve shape determines M,L,T, distance, reddening and metallicity. The ability to derivate metallicity is demonstrated in the figure to the right.

 

 

I have utilised the MACHO lightcurves for LMC and SMC bump Cepheids to extract both mass and luminosity: the result is a mapping of the mass-luminosity relation for intermediate mass stars. This provides us with an accurate determination of the level of internal mixing that occurs on the main sequence.