The orbit of the old, metal-rich, open cluster NGC 6791

¹ European Southern Observatory, Santiago, Chile
² Dept. of Theoretical Physics and Astrophysics, Faculty of Science, Masaryk University, Brno, Czech Republic
³ Dipartimento di Astronomia, Universita di Padova, Padova, Italy
⁴ Astronomical Institute, Academy of Sciences of the Czech Republic, Prague,
⁵ Astronomical Institute, Faculty of Mathematics and Physics, Charles University in Prague, Czech Republic
⁶ Astronomical Institute, Faculty of Mathematics and Physics, Charles University in Prague, Czech Republic
⁷ Astrophysikalisches Institut Potsdam, Potsdam Germany

^a e-mail: ljilkova@eso.org

Abstract

We present a study of the Galactic orbit of the old, metal-rich open cluster NGC 6791. To recover its recent kinematical history we integrate the cluster’s orbit backward in a Milky Way (MW) model including bar and spiral structure. To estimate the viability of one of the cluster’s proposed scenarios of origin we also follow a set of forward integrations originating closer to the Galactic center (GC) where the metal enrichment could be faster. In presence of bar and spiral arms the orbits experience the radial migration due to resonance overlap mechanism [?] and so could possibly reach the recent orbit of NGC 6791.