Photometric versus empirical surface gravities of eclipsing binaries

TL;DRAbstract

. Systematic differences in photometric stellar surface gravity determination are studied by means of the comparison with empirical values derived from detached double-lined eclipsing binaries. Photometric gravities were computed using Moon & Dworetsky (1985) grids based on Kurucz (1979) atmosphere models, and empirical gravities were taken from Andersen (1991). Individual Stromgren colours and fi indices of each component of the binary system have to be taken into account to correctly analyze the observed differences. A compilation of data on a sample containing 30 detached double-lined eclipsing binaries with accurate (ß 1-2%) determination of mass and radius and available uvbyH fi photometric data is also presented. Correction of the differences in terms of T eff and log g for the range 11000 K ! T eff ! 20000 K reduces the mean residuals from 0.13 dex to 0.07 dex. For the range 7000 K ! T eff ! 8500 K, the consideration of metallicity effects by means of ffim ffi index impr

Chat with Paper

AI Agents for this Paper