Astronomers discover new method of planet formation in protoplanetary disc

Scientists at the University of Warwick have made an intriguing discovery - they have identified a previously unknown method of planet formation. They showed that two large planets within a protoplanetary disc can give rise to a smaller planet in between them, a phenomenon they refer to as "sandwiched planet formation."

According to the new theory, two large planets impede the inward flow of dust within the disc. Consequently, the amount of dust that accumulates between these planets is reduced compared to scenarios without an outer planet. If this dust were to eventually coalesce and form a planet, the resulting middle planet would likely be smaller in size than the outer two planets, resembling the filling of a sandwich.

While further investigation is necessary to delve deeper into this field, the "sandwiched planet formation" theory offers a potential explanation for the origin of small planets such as Mars and Uranus in our solar system, which are surrounded by larger planets.

The team's findings have been submitted to the Monthly Notices of the Royal Astronomical Society and presented at the National Astronomy Meeting.

"This is very different to the conventional view of planet formation, where we typically expect that the planets form sequentially from the inside to the outside of the disc and get more and more massive further out. What is also really interesting is that there are examples that we have found from exoplanet observations that actually show this sandwiched planet architecture — where the middle planet is less massive than its neighbours; it is a reasonable proportion of the systems too," said Farzana Meru, an Associate Professor and Dorothy Hodgkin Fellow at the University of Warwick's Department of Physics.

This groundbreaking discovery not only sheds light on the intricate mechanisms of planet formation but also opens up new avenues of exploration.