High-precision parameters and chemical abundances of solar-like stars
Poul Erik Nissen

In this introductory review, I will discuss the accuracy/precision of fundamental parameters and chemical abundances of solar-like stars determined from high resolution spectra with very high signalto- noise. Can we really obtain 1-sigma errors of 10 K in Teff, 0.015 dex in logg, 0.01 dex in abundances, and 1 Gyr in age for solar twins as claimed by several authors? Assuming that the answer is yes, I will review recent findings of trends between abundance ratios, elemental condensation temperature, and stellar age, and discuss how these results may provide new information on extrasolar planets and nucleosynthesis of elements. If time allows, I will also discuss the C/O and Mg/Si ratios in solar-like stars as constraints on the composition of terrestrial planets.