Planets are formed from the accumulation of countless grains of dust that swirl around young stars. New computer simulations have found that planets begin to form earlier than previously thought if a planet’s star is not even finished.
To build a planet, you have to glue a lot, from tiny grains of dust that are invisible to the human eye to objects thousands of kilometers in diameter. Dominant theories of planet formation believed that this gluing process began after a protostar settled, but new research has challenged this view.
Satoshi Ohashi and his colleagues at the RIKEN Star and Planet Formation Laboratory used computer simulations to study the evolution of protoplanetary disks around stars as they formed. They found that gaps in the slices appeared much earlier than expected. These gaps are due to enough grains of dust sticking together for their accumulated mass to clear out channels in the disc.
“We found that ring structures were formed in the early stages of disc formation,” says Ohashi. “This suggests that the dust grains could get bigger sooner than we previously thought.”
This result is surprising since young protostars are still in significant flux and their performance fluctuates greatly. It’s not exactly the best place for dust to stick together quietly.
Nevertheless, observations with the ALMA observatory have revealed gaps in young protoplanetary systems. The simulations by Ohashi and his colleagues have shown how these gaps can appear so quickly.
“Recent ALMA observations have found at least four ring structures in protostellar disks that agree with our simulations,” notes Ohashi.
Hopefully future observations at multiple wavelengths will reveal more structures within the disks, which can help further verify the computer simulations and help researchers understand this complex, dusty process.