Site Map
Follow us on Facebook Follow us on Twitter YouTube channel
Centro de Astrofísica da Universidade do Porto

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

Context. 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.
Aims: 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.
Methods: We used VLT/UVES to obtain high-resolution near-UV spectra of our targets. Spectral synthesis of the NH band at 3360 Å was performed with the spectral synthesis codes MOOG and FITTING.
Results: 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.
Conclusions: We conclude that reliable N abundances can be derived for metal-rich solar type stars from the near UV molecular band at 3360 Å. We confirm a linear trend between [N/Fe] and metallicity expected from standard models of Galactic chemical evolution.

stars: abundances, stars: chemically peculiar, planetary systems

Astronomy and Astrophysics
Volume 591
June 2016

>> PDF>> ADS>> DOI

Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

Proceed on CAUP's website|Go to IA website