A team of researchers at the University of Sheffield in the UK has discovered two exoplanets that appear to have been “hijacked”. They are gas giants the size of Jupiter orbiting massive stars hundreds of times between the Earth and the sun. Since these stars emit a large amount of radiation, the planets would be expected to be smaller; So the authors believe the stars picked them up.
Exoplanets (the name given to worlds orbiting other stars) were discovered by the Exoplanet Abundance Study of Star B (BEAST), and represent unknowns to star formation processes. “While planets can form around massive stars, it’s hard to imagine gas giant planets like Jupiter and Saturn forming in such hostile environments,” explained Richard Parker, co-author of the study.
According to him, the radiation from the stars can evaporate these planets before they are ready. By simulating the conditions of stellar nurseries, the researchers found that “stolen” planets from there could orbit stars at distances similar to those observed. Therefore, the new study indicates that BEAST planets did not form in the systems in which they exist, but were “hijacked” from smaller stars in a stellar nursery.
Study co-author Emma Davern-Powell describes the process as “planetary abduction. We know that massive stars have a greater impact on these nurseries than Sun-like stars, and we’ve found that they can capture or steal planets,” he said. They occur, on average, in the first 10 million years of the evolution of the star-forming region.
For Parker, BEAST exoplanets are another type of known and very diverse exoplanet system. He concluded, “Our results lend more credence to the idea that planets in farther orbits, more than 100 times the distance between the Earth and the Sun, may not orbit their parent stars.”
The article with the results of the study was published in the journal Monthly notifications of the Royal Astronomical Society.
source: Monthly Notices of the Royal Astronomical Society; Across: University of Sheffield
