CN and CH bands in Exoplanet Host Stars

Abstract

En este trabajo medimos la intensidad de las bandas moleculares CN y CH en una muestra de estrellas con y sin exoplanetas (indices δS3839, δS4142 y δCH4300). El índice δS3839 parece ser menor en estrellas sin exoplanetas. El hecho de que la banda CN aumente con la metalicidad, puede explicar al menos en parte las diferentes distribuciones observadas en estrellas con y sin exoplanetas. Advertimos que hasta el momento las muestras son relativamente pequeñas.

We measured the strength of CN and CH molecular bands in a sample of stars with and without exoplanets (indices δS3839, δS4142 and δCH4300). The index δS3839 seem 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 seem to increase with C, N and Fe abundances. This could explain at least in part the dissimilar 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.