Research sheds light on formation of giant planets
A team of researchers from LMU has created a new model to explain the formation of giant planets including Jupiter. This offers new insights into the process of planet formation and could help our understanding of planetary systems. The research was titled “Sequential giant planet formation initiated by disc substructure. Astronomy & Astrophysics.”
Previous theories have assumed that giant planets are formed by collisions and accumulations of asteroid-like celestial bodies called planetesimals, along with the subsequent accretion of gas over millions of years. These models however do not explain why gas giants far from their star form nor do they explain the formations of Uranus and Neptune out on the edge of our solar system.
Astrophysicists from LMU, the ORIGINS cluster, and MPS have created the first ever model that incorporates all the necessary physical processes that play a part in the formation of planets. Using it, they have revealed that annular perturbations the protoplanetary discs can trigger the rapid formation of multiple gas giants. These results match the latest observations and can suggest that these bodies form faster and more efficiently than previously thought.
With their model, the team demonstrated how millimetre-sized dust particles accumulate aerodynamically in the turbulent disc of gas and how this initial perturbation traps dust. This makes the growth of planets very efficient. As a result of this, a lot of “building material” is available and within a small enough area where the right conditions for the planet’s formation are present.
In our solar system, the four gas giants are located between five to thirty times the distance from the Earth to the Sun (known as astronomical units or au). 1 au is around 150 million kilometres.
This research shows that in other solar systems, this process can be set in motion at much larger distances and this can still happen very quickly. The ALMA radio observatory has witnessed such systems including gas giants in young discs at a distance of over 200 au.
The model also seems to explain why our own solar system stopped forming any more planets after Neptune, the building material had been used up already.
The results of this study match observations of young planetary systems. They could refine our understanding of the origin and development of giant planets including the gas giants within our own solar system and help to explain the diversity of the planetary systems we’ve observed.
Image: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill
