The Habitability and Stability of Earth-Like Planets in Binary Star Systems

John E. GizisIn 2011, NASA's Kepler spacecraft observed the first planet to be detected in a known binary star system, Kepler 16-b. Its discovery has sparked new discussion on the potential of binary systems supporting habitable Earth-like planets. In this study, by using relatively simple computation models, we are able to shed new light and place new limitations on this discussion. Habitable Zone geometry in binary systems is discussed as a part of this study, in which we are able to classify binary habitable zones into two major classes of merged and unmerged, with important special cases of each class presented. We were able to learn a good deal about the behavior of planets in S-type binary orbits, and the possibility of life on those planets. The effect of the orbit of the planet on the climate as well as how the planet experiences day and night are discussed, and we also present a lower limit for the binary separation at which a binary system would fail to have a habitable S-type orbit. In addition, we explore the possibility that a planet could remain habitable in a transfer orbit between the system's two stars or in orbit around one of the system's Lagrange Points. In this endeavor, we derive an analytical expression for the surface temperature of an Earth-like planet at a binary system's stable L4 and L5 Lagrange Points, which closely match simulated results. We find definite possibilities for habitable L4 and L5 Lagrange Points in binary systems over a wide range of stellar masses and mass ratios. Finally, we propose many extensions and improvements to this study that would be worthwhile to pursue.Physic