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We have investigated the thorium (Th) abundance in a sample of 53 thin disc solar twins covering a wide range of ages. These data provide constrains on the mantle energy budget of terrestrial planets that can be formed over the evolution of the Galaxys thin disc. We have estimated Th abundances with an average precision of 0.025,dex (in both [Th/H] and [Th/Fe]) through comprehensive spectral synthesis of a Th,II line present at 4019.1290,{AA}, using very high resolution (R,=,115,000) high quality HARPS spectra obtained at the ESO La Silla Observatory. We have confirmed that there is a large energy budget from Th decay for maintaining mantle convection inside potential rocky planets around solar twins, from the Galactic thin disc formation until now, because the pristine [Th/H]$_{rm ZAMS}$ is super-solar on average under a uniform dispersion of 0.056,dex (varying from +0.037 up to +0.138,dex based on linear fits against isochrone stellar age). Comparing to neodymium (Nd) and europium (Eu), two others neutron-capture elements, the stellar pristine abundance of Th follows Eu along the Galactic thin disc evolution, but it does not follow Nd, probably because neodymium has a significant contribution from the $s$-process (about 60,per,cent).
We present the first investigation of Th abundances in Solar twins and analogues to understand the possible range of this radioactive element and its effect on rocky planet interior dynamics and potential habitability. The abundances of the radioacti
Since there are several ways planets can survive the giant phase of the host star, we examine the habitability and detection of planets orbiting white dwarfs. As a white dwarf cools from 6000 K to 4000 K, a planet orbiting at 0.01 AU would remain in
A large dataset of ~2800 spectra extracted from the ELODIE archive was analysed in order to find solar twins. A list of stellar spectra closely resembling the spectrum of the Sun was selected by applying a purely differential method, directly on the
We present 63 Solar analogues and twins for which high S/N archival data are available for the HARPS high resolution spectrograph at the ESO 3.6m telescope. We perform a differential analysis of these stellar spectra relative to the Solar spectrum, s
Abundances of light elements in dwarf stars of different ages are important constraints for stellar yields, Galactic chemical evolution and exoplanet chemical composition studies. We have measured C and N abundances and $^{12}$C/$^{13}$C ratios for a