Constraining the Radiation and Plasma Environment of the Kepler Circumbinary Habitable Zone Planets

Abstract

The discovery of many planets using the Kepler telescope includes ten planets orbiting eight binary stars. Three binaries, Kepler-16, Kepler-47, and Kepler-453, have at least one planet in the circumbinary habitable-zone (BHZ). We constrain the level of high-energy radiation and the plasma environment in the BHZ of these systems. With this aim, BHZ limits in these Kepler binaries are calculated as a function of time, and the habitability lifetimes are estimated for hypothetical terrestrial planets and/or moons within the BHZ. With the time-dependent BHZ limits established, a self-consistent model is developed describing the evolution of stellar activity and radiation properties as proxies for stellar aggression toward planetary atmospheres. Modeling binary stellar rotation evolution, including the effect of tidal interaction between stars in binaries is key to establishing the environment around these systems. We find that Kepler-16 and its binary analogs provide a plasma environment favorable for the survival of atmospheres of putative Mars-sized planets and exomoons. Tides have modified the rotation of the stars in Kepler-47 making its radiation environment less harsh in comparison to the solar system. This is a good example of the mechanism first proposed by Mason et al. Kepler-453 has an environment similar to that of the solar system with slightly better than Earth radiation conditions at the inner edge of the BHZ. These results can be reproduced and even reparametrized as stellar evolution and binary tidal models progress, using our online tool http://bhmcalc.net.

18 pages, 9 figures. Accepted for publication in ApJ. It includes an improved model for BHZ calculation and comparisons among different methods. For reproducing these results and performing new ones please refer to the Binary Habitability Calculator in http://bhmcalc.net

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Cited by in corpus (13)

• The solar wind in time: a change in the behaviour of older winds?
• Milankovitch Cycles of Terrestrial Planets in Binary Star Systems
• Ploonets: formation, evolution and detectability of tidally detached exomoons
• Stability of exomoons around the Kepler transiting circumbinary planets
• Habitability properties of circumbinary planets
• Eta-Earth Revisited II: Deriving a Maximum Number of Earth-like Habitats in the Galactic Disk
• Stellar activity and planetary atmosphere evolution in tight binary star systems
• Statistical properties of habitable zones in stellar binary systems
• Analyzing the Habitable Zones of Circumbinary Planets Using Machine Learning
• The Habitable Zone of Kepler-16: Impact of Binarity and Climate Models
• Fitting Formulae and Constraints for the Existence of S-type and P-type Habitable Zones
• Orbital evolution of potentially habitable planets of tidally interacting binary stars
• Formation of Earth-sized planets within the Kepler-1647 System Habitable Zone