CN and CH bands in Exoplanet Host Stars

SAFFE, CARLOS; JOFRÉ, EMILIANO; PETRUCCI, ROMINA

San Juan

Congreso; 54° Reunión Anual de la Asociación Argentina de Astronomía; 2011

We measured the strength of the CN and CH molecular bands in a sample of stars with and without exoplanets and then corrected by temperature and gravity effects (indices deltaS3839, deltaS4142 and deltaCH4300). The index deltaS3839 seems to present smaller values for stars without exoplanets. No correlation is found between molecular bands and exoplanet parameters, supporting the primordial hypothesis of planet formation. The CN band strength seems to increase with the C, N and Fe abundances. This could explain at least in part the disimilar distributions of CN observed for stars with and without exoplanets. We caution that this is an initial result based in relatively small number of objects (a total of 57 stars) and expect to improve the statistical significance.