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Centro de Astrofísica da Universidade do Porto

Measuring Be depletion in cool stars with exoplanets

E. Delgado Mena, G. Israelian, J. I. González Hernández, N. C. Santos, R. Rebolo López

Abstract
We present new UVES spectra of a sample of 14 mostly cool unevolved stars with planetary companions with the aim of studying possible differences in Be abundance with respect to stars without detected planets. We determine Be abundances for these stars that show an increase in Be depletion as we move to lower temperatures. We carry out a differential analysis of spectra of analog stars with and without planets to establish a possible difference in Be content. While for hot stars no measurable difference is found in Be, for the only cool (Teff ∼ 5000 K) planet host star with several analogs in the sample we find enhanced Be depletion by 0.25 dex. This is a first indication that the extra-depletion of Li in solar-type stars with planets may also happen for Be, but shifted towards lower temperatures (Teff < 5500 K) due to the depth of the convective envelopes. The processes that take place in the formation of planetary systems may affect the mixing of material inside their host stars and hence the abundances of light elements.

Keywords
planetary systems - planets and satellites: formation - stars: abundances - stars: atmospheres - stars: fundamental parameters

Notes
Based on observations made with UVES at VLT Kueyen 8.2 m telescope at the European Southern Observatory (Cerro Paranal, Chile) in programme 75.D-0453A

The Astrophysical Journal
Volume 728, Page 148_1
February 2011

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