A new method of planet formation, in which two large planets in the protoplanetary disk can potentially give rise to a smaller planet between them, which they have called ‘sandwich planet formation’, scientists at the University of Warwick have discovered. The research was presented at Britain’s Royal Astronomical Society’s National Astronomy Meeting and submitted to the journal Monthly Notices.

The researchers probed the planets’ birth environments, regions of gas and dust that swirl around a central star and are known as the protoplanetary disk. Previous observations have shown that rings and voids exist in protoplanetary disks. Also, that the planets cause dust rings to form just outside them.

According to the new study, this “sandwich” effect occurs because two primordial, large planets restrict the inward flow of dust, meaning the amount of dust that collects between them is reduced compared to if there was no outer planet. . If this dust eventually aggregates to form a planet, then the middle planet will likely be smaller than the outer two, like the filling of a sandwich.

Although further research is needed, this theory could be a possible explanation for the formation of small planets, such as Mars and Uranus, which are surrounded by larger planets.

Associate Professor in the Department of Physics at the University of Warwick, Farzana Merou, explains that “in our study we suggest the rings as sites of planet formation, specifically that there are sandwich planets currently forming in the rings. This is very different from the conventional view of planet formation, where we usually expect planets to form sequentially from the interior to the exterior of the disk and become increasingly massive outwards.”