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arXiv · 1605.03049

CNO behaviour in planet-harbouring stars. I Nitrogen abundances in stars with planets

L. Suárez-Andrés·G. Israelian·J. I. González Hernández·V. Zh. Adibekyan·E. Delgado Mena·N. C. Santos·S. G. Sousa
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Abstract

Carbon, nitrogen, and oxygen (CNO) are key elements in stellar formation and evolution, and their abundances should also have a significant impact on planetary formation and evolution. We present a detailed spectroscopic analysis of 74 solar-type stars, 42 of which are known to harbour planets. We determine the nitrogen abundances of these stars and investigate a possible connection between N and the presence of planetary companions. We used VLT/UVES to obtain high-resolution near-UV spectra of our targets. Spectral synthesis of the NH band at 3360A was performed with the spectral synthesis codes MOOG and FITTING. We identify several spectral windows from which accurate N abundance can be obtained. Nitrogen distributions for stars with and without planets show that planet hosts are nitrogen-rich when compared to single stars. However, given the linear trend between [N/Fe] vs [Fe/H], this fact can be explained as being due to the metal-rich nature of planet hosts. We conclude that reliable N abundances can be derived for metal-rich solar type stars from the near UV molecular band at 3360A. We confirm a linear trend between [N/Fe] and metallicity expected from standard models of Galactic chemical evolution.

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L. Suárez-Andrés, G. Israelian, J. I. González Hernández, V. Zh. Adibekyan, E. Delgado Mena, N. C. Santos, S. G. Sousa. 2016-05-10. CNO behaviour in planet-harbouring stars. I Nitrogen abundances in stars with planets. https://doi.org/10.1051/0004-6361/201628455

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