Estudio de las abundancias químicas de estrellas ricas en Helio

LÓPEZ GARCÍA, Z.; MALARODA, S.; LEONE, F.; ALONSO, M. S.

Gonnet, La Plata

Congreso; Asociación Argentina de Astronomía; 1998

Asociacion Argentina de Astronomía

High resolution spectroscopic material in the 460 - 700 nm range has been used to perform an abundance analysis of the elements Si, Cr and Fe for three Helium-rich stars, HD 36485, HD 37479 and HD 37776. The atmospheric parameters,Teff and log g were determined from the photometric colors and when the abundances were indicative of an enhanced metallicity, we have adopted the effective temperature and gravity using the Napiwotzki et al.(1993) calibration for CP stars. The abundances were inferred using WIDH9 code with a metal opacity equal to three times the solar value. In the three stars studied, Cr and Fe are overabundant by factors 100 and 3, respectively, while Si is deficient in all the stars by a factor 3.