On the stability and collisions in triple stellar systems

Understand

A significant fraction of main sequence stars are part of a triple system.

• We study the long-term stability and dynamical outcomes of triple stellar systems using a large number of long-term direct N-body integrations with relativistic precession.
• We find that the previously proposed stability criteria by Eggleton & Kiseleva 1995 and Mardling & Aarseth 2001 predict the stability against ejections reasonably well for a wide range of parameters.
• Assuming that the triple stellar systems follow orbital and mass distributions from FGK binary stars in the field, we find that in ~1% and ~0.5% of the triple systems lead to a direct head-on collision (impact velocity ~ escape velocity) between main sequence (MS) stars and between a MS star and a stellar-mass compact object, respectively.