C. Saffe and H. Levato
Instituto de Ciencias Astronómicas, de la Tierra y del Espacio (ICATE), C.C. 467, 5400, San Juan, Argentina. Members of the Carrera del Investigador Científico, Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina (CONICET). (csaffe@casleo.gov.ar, hlevato@casleo.gov.ar).
Received 2009 May 22
Accepted 2009 June 29
RESUMEN
]]> Presentamos un análisis de las estrellas Ap(Si) HD 87405 y HD 146555 usando modelos de atmósferas de ATLAS9. Estas estrellas químicamente peculiares (CP) pertenecen a los cúmulos abiertos australes NGC 3114 y NGC 6087, respectivamente. Para ambas estrellas el C y el Ca (sólo una línea) son ~ solares, el Mg, y el S se encuentran levemente por debajo del valor solar y el Si es sobreabundante por factores entre ~ 4 — 6. Los elementos más pesados son todos sobreabundantes, el Ti, y el Cr por factores de ~ 50, mientras que el Mn es sobreabundante por factores de ~ 50 y ~ 120, para HD 87405 y HD 146555, respectivamente. El Fe es ~ 10 veces solar, el Sr, el Y, y el Zr son sobreabundantes por factores entre ~ 100 —1000 y las tierras raras por factores de ~ 1000 o más. Este trabajo es parte de un estudio para verificar la posible existencia de una tendencia entre las abundancias con la edad de estrellas CP en cúmulos abiertos.
ABSTRACT
In this paper we present an analysis of the Ap(Si) stars HD 87405 and HD 146555 using an ATLAS9 model atmospheres. These Chemically Peculiar (CP) stars belong to the southern hemisphere open clusters NGC 3114 and NGC 6087, respectively. For HD 87405 and HD 146555, C and Ca (only one line) are mostly solar, Mg and S are slightly underabundant, while Si is overabundant by factors between ~ 4 — 6. Heavier elements are all overabundant, Ti, Cr by factors of ~ 50, while Mn is nearly ~ 50 and ~ 120 times overabundant for HD 87405 and HD 146555, respectively. Fe is ~ 10 times solar, Sr, Y, Zr are overabundant by factors between ~ 100 — 1000 and rare earth by factors of ~ 1000 or more. This work is part of our current study for verifying a possible tendence of abundances with the age of CP stars in open clusters.
Key Words: stars: chemically peculiar — stars: individual (HD 87405, HD 146555).
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