How unique is the local region of the Galaxy disk?

Abstract

We present the results of a spectroscopic study of over 500 dwarf and giant stars within 100 pc of the Sun. Using stellar metallicity data, the goal of this study is to determine whether there are any significant variations of metallicity related to stellar characteristics or location in the Galaxy. The abundance data are based on high-resolution spectroscopy and correlated with kinematical properties based on Hipparcos data. The spectroscopic data are made available to the public through an online database. We find that most elements behave as expected from Galactic chemical evolution and are consistent with standard stellar evolution. Interesting trends are found for some elements, e.g. Mn and probably Ba. There is evidence for systematic carbon abundance variations in the red giant clump. To determine the uniqueness of the local region, in particular at its galactocentric radius, one should consider in-depth spectroscopic and kinematic studies of dwarfs and giants in similar-sized volumes in other regions of the disc. This will require accurate positions, distances and space motions out to hundreds of parsecs from space missions such as Gaia and next-generation telescopes for high-resolution spectroscopy.