8-12 juin, 2014


Vertical abundance stratification of elements in the post-HB star HD 76431

Boukari Yameogo (University of Moncton)

V. Khalack, F. LeBlanc, G. Fontaine, E. Green, V. Van Grootel, P. Petit

Spectral analysis of CFHT ESPaDOnS spectra of the post-HB star HD 76431 was undertaken to search for vertical abundance stratification in its atmosphere. The values of the effective temperature, surface gravity and average abundances of the elements analysed are consistent with previous studies. Detection of vertical stratification of carbon and nitrogen abundances in the atmosphere of HD 76431 is found. To our knowledge, this is the first discovery of vertical abundance stratification in a post-HB star. Up to now, this is also the hottest star that shows such stratification.