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تسجيل مستخدم جديدThe Hydrogen Ionization Front-Stellar Photosphere Interaction and the Period-Color Relations of Variable Stars
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S. Kanbur
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Recent evidence has emerged that the Cepheid PL relation in the LMC is nonlinear in the sense that the existing data are more consistent with two lines of differing slope with a break at a period of 10 days. We review the statistical evidence for this, the implications for the extra-galactic distance scale and CMB independent estimations of Hubbles constant and briefly outline one possible physical mechanism which could cause this nonlinearity.
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Period-color (PC) relations may be used to study the interaction of the stellar photosphere and the hydrogen ionization front (HIF). RR Lyraes (RRLs) and long period classical Cepheids (P > 10d) have been found to exhibit different PC behavior at min
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