Bibcode
Delgado Mena, E.; Adibekyan, V. Zh.; Figueira, P.; González Hernández, J. I.; Santos, N. C.; Tsantaki, M.; Sousa, S. G.; Faria, J. P.; Suárez-Andrés, L.; Israelian, G.
Referencia bibliográfica
Publications of the Astronomical Society of the Pacific, Volume 130, Issue 991, pp. 094202 (2018).
Fecha de publicación:
9
2018
Número de citas
11
Número de citas referidas
11
Descripción
To understand the formation and composition of planetary systems it is
important to study their host stars composition since both are formed in
the same stellar nebula. In this work, we analyze the behaviour of
chemical abundances of Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd, and Eu in the
large and homogeneous HARPS-GTO planet search sample (R ˜ 115000).
This sample is composed of 120 stars hosting high-mass planets, 29 stars
hosting exclusively Neptunians and Super-Earths and 910 stars without
detected giant planets. We compare the [X/Fe] ratios of such elements in
different metallicity bins and we find that planet hosts present higher
abundances of Zn for [Fe/H] < -0.1 dex. On the other hand, Ba,
Sr, Ce, and Zr abundances are underabundant in stars with planets, with
a bigger difference for stars only hosting low-mass planets. However,
most of the offsets found can be explained by differences in stellar
parameters and by the fact that planet hosts at low metallicity mostly
belong to the Galactic thick disk. Only in the case of Ba we find a
statistically significant (3σ) underabundance of 0.03 dex for
low-mass planet hosts. The origin of these elements is quite complex due
to their evolution during the history of the Galaxy. Therefore, it is
necessary to understand and characterize the stellar populations to
which planet hosts belong in order to do a fair comparison with stars
without detected planets. This work demonstrates that the effects of
Galactic chemical evolution and not the presence of planets mostly
account for the differences we find.
Based on observations collected at the La Silla Observatory, ESO
(Chile), with the HARPS spectrograph at the 3.6 m ESO telescope (ESO
runs ID 72.C—0488, 082.C—0212, and 085.C—0063).
Proyectos relacionados
Pruebas Observacionales de los Procesos de Nucleosíntesis en el Universo
Recientemente se han llevado a cabo varios análisis espectroscópicos de estrellas con planetas. Uno de los resultados más relevantes ha sido descubrir que las estrellas con planetas son en promedio más metálicas que las estrellas del mismo tipo espectral sin planetas conocidos (Santos, Israelian & Mayor 2001, A&A, 373, 1019; 2004, A&A, 415, 1153)
Garik
Israelian