Exploring the orbits of the star via chemical tagging techniques

¹ Department of Physics and Astronomy, Macquarie University, North Ryde, NSW 2109, Australia
² Australian Astronomical Observatory, North Ryde, NSW 2113, Australia
³ Department of Physics and Astronomy, Macquarie University, North Ryde, NSW 2109, Australia

Abstract

Using the chemical groups identified by Mitschang et al. (2014) on a local sample of around 700 stars by Bensby et al. (2014) and the new derived ages, I report some properties on the orbital parameters (R_min, R_max, e, Z_max, angular momentum) and their temporal evolution. We find that the < R_max > is nearly independent of age with values from 9 to 11 kpc, while < R_min > shows a clear trend with age. The < e > and < Z_max > for the chemical groups clearly increase with age.

These preliminary results show a significant variety of orbits for the members inside a chemical group, that may support the idea of the identification of co-eval groups (born same time, not necessarily same place) rather than co-natal (Anguiano et al. in prep.)