Tatooine is the home world of Luke Skywalker in Star Wars and was an inspirational sight for many of the movie's fans. In that plane where truth meets fiction, worlds similar to the planet with two suns may be more common than once believed.
Exoplanets, once the subject of science fiction stories, are now known to be commonplace. More than 1,000 alien worlds are now confirmed orbiting hundreds of stars. Astronomers once believed that planets in binary star systems would be rare, due to the complex gravitational interactions between the bodies.
"Tatooine in Star Wars was inspirational to many of us. It was disappointing when earlier theories predicted that making Earth-like planets would be problematic or impossible. Our work shows that nature provides a clear path for making planets around binary stars, following the same recipe as for Earth," Ben Bromley of the University of Utah said.
Complex mathematical equations revealed that planetesimals, asteroid-sized bodies that can coalesce into rocky worlds, can exist within binary systems. Researchers summarized their work in a paper titled "Planet formation around binary stars: Tatooine made easy."
"We took our sweet numerical time to show that the ride around a pair of stars can be just as smooth as around one. The 'made easy' part is really saying the same recipe that works around the sun will work around Tatooine's host stars," Bromley said.
The new study reveals that planets are unlikely to form close to pairs of binary stars where gravitation can have irregular influences on the orbit of the planet. However, it also suggests that worlds forming further from the suns could maintain stable orbits, much as if there were just a single star.
Binary stars are common throughout the galaxy, making up about half of all known star systems. In the quest to find alien life, astronomers will need to have a better understanding about if - or how - rocky planets can form in such stellar families.
Dust and other material orbiting binary systems is largely drawn into the stars, except for the debris within the most circular orbits in relation to their suns, the study reveals. However, gravitational influences generate flows and eddies which result in the accumulation of material which can form planets.
Only gas giants, similar to Jupiter and Saturn, have been found in binary star systems so far. Life is unlikely to exist on these worlds, although their moons could still harbor various lifeforms.
"Star Wars: Episode 7 - The Force Awakens," the latest installment in the science fiction series of films, will open in theaters on Dec. 18. Will moviegoers get to visit another planet that has twin sunsets because it orbits two stars?
The study of how rocky planets can form in binary star systems was submitted for publication in the Astrophysical Journal.
Photo: Matt Hendrick | Flickr
