Volume 384, Number 3, March IV 2002
|Page(s)||1030 - 1037|
|Section||Interstellar and circumstellar matter|
|Published online||15 March 2002|
Relative orientation of orbits in triple stars *
European Southern Observatory, Casilla 19001, Santiago 19, Chile
2 Cerro Tololo Inter-American Observatory, Casilla 603, La Serena, Chile
Corresponding author: M. Sterzik, email@example.com
Accepted: 15 January 2002
Statistical analysis of the relative alignment of inner and outer orbits in triple systems resulting from a dynamical decay of small-N clusters () is presented and compared to the statistics of real multiple stars. The distribution of the relative angle Φ between the angular momentum vectors of inner and outer orbits in triple stars formed by decay is shown to depend on the initial cluster conditions like geometry, mass function, rotational and thermal energy. For a realistic set of initial conditions, a modest alignment of orbital momentum vectors is found, in good agreement with the latest observational data on visual multiple stars exhibiting an average between and . The relation between eccentricities of outer orbits and period ratios for both simulated and real triples is consistent with a slightly adjusted formulation of the stability criterium by Mardling & Aarseth (2001). Dynamical decay can therefore explain the weak correlation of orbital orientations observed in multiple stars. Using modern high-resolution techniques, the observed statistics of Φ should be extended as it will allow one to sensitively constrain properties of initial clusters.
Key words: stars: binaries: general / visual / stars: formation / stellar dynamics
© ESO, 2002
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.