New theory explains how exoplanets form | Digital Trends Spanish
Outside of our Solar System and despite the fact that the possibilities of the universe are infinite, scientists know that the variety of exoplanets is limited to two large families: super earthsbasically rocky planets with a mass between one and ten times that of our planet, or mini neptunes, gaseous dwarfs that have a liquid ocean surrounded by a thick atmosphere of hydrogen and helium. The duality of this type of planets has generated all kinds of theories, one of the most accepted being that the super-earths are the remnants of mini-neptune victims of terrible radiation. Today, this theory is refuted by a study conducted by scientists at McGill University in Canada and published in the The Astrophysical Journal.
According to experts, not all super-earths outside the confines of the Solar System were minineptunes, whose atmospheres were swept away by radiation emitted by the stars in each system.
“Our theory shows that some exoplanets could never have a gaseous atmosphere,” says Eve Lee, an associate professor in the Department of Physics at McGill University.
The researcher bases her theory on the results of thermodynamic calculations based on the size of the rocky cores of exoplanets, the distance that separates them from their stars and the temperature of the gas clouds that surround them. The data obtained suggests that exoplanets are formed from a single rock distribution formed in a disk of gas and dust around the stars in each system. “Some rocks form gas shells, while others remain exclusively rocky,” Lee explains.
“Our findings could help explain the origin of these two families of exoplanets and probably also their prevalence,” concludes the scientist.
For now, astronomical observations show that 30 to 50 percent of exoplanets outside the solar system belong to the super-earth and mini-neptune families.