The Dynamical Evolution of the Multiple Stellar System α Gem

Resumo

The sextuple system Castor (a Gem) comprises of a visual binary (Castor A and B) with an orbital period of approximately 460 years. Each of these components is a single-lined spectroscopic binary with an orbital period of only a few days. In addition, a distant double-lined spectroscopic eclipsing binary (Castor C, or YY Gem), with an orbital period of less than 1 day, is considered to be in orbit around them with a period of roughly 14 000 years or more. In this contribution, we study the long-term dynamics of this hierarchical system. Many orbital elements still remain unknown, mainly those regarding the AB-C system. Apart from the direct integration of the equations of motion for the quadruple (Aa,Ab)-(Ba,Bb) system, we also perform a qualitative analysis of the global system by means of numerical techniques in order to find the most distinctive features of its dynamics.