Over 3,700 exoplanets have been found lurking around our universe, and although each has its own unique set of characteristics, the vast majority have one thing in common: they orbit a single star. Researchers once believed that it would be near impossible for planets to survive outside of single-star systems, but now, an international team of researchers has shown that exoplanets in double- and triple-star systems could easily survive, and created a map of where to find them.
Led by Franco Busetti of the University of the Witwatersrand in South Africa (Wits), the group of researchers set out to determine the long-term survival rates of exoplanets within binary systems, where one star orbits another, and triple-star systems, where a third star orbits the binary pair. Their research will be published in the journal Astronomy & Astrophysics.
In single-star systems, planets use the gravitational pull of their host stars to situate themselves in stable, near-circular orbits. But what happens when the gravitational pull of a second, or even a third star gets thrown into the mix?
"Because of the complex dynamics between these stars and planets, it was previously thought improbable that many planets would have stable orbits in these regions," said Busetti in a news release.
Less than 40 of the 3,700 confirmed exoplanets live in triple-star systems, but Busetti and his colleagues, Charis Harley of Wits and Hervé Beust the University of Grenoble Alpes in France, believe that they exist in much higher numbers. To find out, they combined factors like orbits, masses, and dimensions to create 24 different combinations of stellar variables. Over a three-year period, they used these combinations to conduct more than 45,000 computer simulations of double- and triple-star systems.
