The Universe is full of solar systems which are quite different from the one we live in, and that’s mostly because of the host stars of those planetary systems. While in our solar system Mercury is orbiting the Sun in 88 days and it’s the smallest planet in the system, other stars in the Universe host Super-Earth exoplanets that orbit so close to them that fulfill a complete rotation in around ten days.
That feat has puzzled the scientists since the discovery of the first such planet, but now, the researchers might finally have the answer on why Super-Earth exoplanets orbit very close to their host stars.
A team of astronomers noted, during a study, that these type of exoplanets, which form in the chaos produced by strong gravitational forces, magnetic fields, and hydrodynamic forces, and by the interactions with the gaseous protoplanetary disk which surrounds a star when a solar system is forming, slide towards their host stars.
Here Is Why Super-Earth Exoplanets Orbit Very Close To Their Host Stars
Super-Earth exoplanets are the most common form of rocky planets located outside our solar system, and the majority of those alien worlds orbit very tightly to their host stars. The team of researchers conducted computer simulations to see why Super-Earth exoplanets slide towards their host stars. The results of the simulations matched the data on such planetary systems gathered by NASA’ Kepler.
“When stars are very young, they are surrounded by a disc that is mostly gas with some dust—and that dust grows into the planets, like the Earth and these super-Earths. But the particular puzzle for us is that this disc doesn’t go the all way to the star—there’s a cavity there. And yet we see these planets closer to the star than the edge of that disc,” explained Daniel Carrera, a researcher from Penn State’s Eberly College of Science.
“We’ve shown that it’s possible for planets to get that close to a star in this simulation, but it doesn’t mean that it’s the only way that the universe chose to make them. Someone might come up with a different idea of a way to get the planets that close to a star. And, so, the next step is to test the idea, revise it, make predictions that you can test against observations,” Carrera added. Further studies might offer a more definite answer on why Super-Earth exoplanets orbit close to their host stars.