Chemical abundances for the transiting planet host stars OGLE-TR-10, 56, 111, 113, 132 and TrES-1. Abundances in different galactic populations

TL;DR

This study analyzed the chemical compositions of six stars hosting transiting planets using high-resolution spectra, finding they are similar to local thin disk stars and show no signs of planetary material accretion.

Contribution

First detailed chemical abundance analysis of transiting planet host stars using high-resolution spectroscopy and LTE modeling.

Findings

Stars are chemically similar to local thin disk stars.

No evidence of accretion of planetary material based on abundance patterns.

Stars are metal-rich and located up to 2 Kpc from the Sun.

Abstract

We used the UVES spectrograph (VLT-UT2 telescope) to obtain high-resolution spectra of 6 stars hosting transiting planets, namely for OGLE-TR-10, 56, 111, 113, 132 and TrES-1. The spectra are now used to derive and discuss the chemical abundances for C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu and Zn. Abundances were derived in LTE, using 1-D plane-parallel Kurucz model atmospheres. For S, Zn and Cu we used a spectral synthesis procedure, while for the remaining cases the abundances were derived from measurements of line-equivalent widths. The resulting abundances are compared with those found for stars in the solar neighborhood. Distances and galactic coordinates are estimated for the stars. We conclude that besides being particularly metal-rich, with small possible exceptions OGLE-TR-10, 56, 111, 113, 132 and TrES-1 are chemically undistinguishable from the field (thin disk) stars regarding their [X/Fe] abundances. This is particularly relevant for the most distant of the targets, located at up to ~2 Kpc from the Sun. We also did not find any correlation between the abundances and the condensation temperature of the elements, an evidence that strong accretion of planetary-like material, tentatively connected to planetary migration, did not occur.