The Stability of the Double Binary System PH1


In October of 2012, the first four-star planet was confirmed by the Planet Hunters program from Yale. The planet – called Planet Hunters 1 (PH1) – is a circumbinary planet meaning it is orbiting a pair of stars instead of just one. Furthermore, orbiting that pair of stars is another pair meaning this planet is in a system with four stars total. With so many large forces acting on this system, the stability is, of course, a question of concern. According to the paper announcing PH1’s discovery, though, “the system is indeed stable on gigayear timescales” (Schwamb 2013). This implies there are formation possibilities never considered and is inspiring further study of PH1.


Using the Kepler Space Telescope, astronomers and planet hunters have discovered and confirmed 1,020 planets from the time of its launch in 2009 and the time of this writing. There are still over 4,600 extraterrestrial objects that seem to be planets; they just have not been studied enough to be confirmed yet. Along with those confirmed and unconfirmed planets, Kepler has discovered 2,165 binary star systems({Kepler Website}). The question then becomes, though, are these binary systems stable? The goal of this paper is to

  1. Analyze Holman and Wiegert’s paper Long-Term Stability of Planets in Binary Systems (Holman 1999) to fully understand what makes such a system stable and

  2. Apply theses finding to the system PH1 to find if it, too, is stable

The Simulation Process

Holman and Wiegert begin by addressing the question of where planets can