Like rocks in a river

The Dustbusters are a group of astronomers from around the world who are using the latest high-resolution telescopes and instruments to study ‘baby’ planets shortly after they have formed.

Very few of these new planets have been seen, but the Dustbusters’ work is pointing astronomers to where they should be looking.

They are using the flow of gas around a young star known as HD97048, about 500 light years away, to get a better understanding of a new planet which is up to three times the mass of Jupiter.

The project is led by the Universita Degli Studi di Milano with 13 collaborators in France, Chile, the USA, UK, the European Southern Observatory, and Monash University in Australia. Together, they are developing numerical algorithms and techniques to better understand how newborn planets react with the gas and dust in their environment.

The process is like finding a submerged rock in a river using the disturbance in the flow of water around it.

Planet formation is a by-product of the process of star formation itself and occurs within relatively thin and dense discs made of gas and dust that orbit the newborn star.

Astronomers can now probe these discs with unprecedented detail thanks to telescopes and instruments, such as the Atacama Large Millimeter Array (ALMA) and the SPHERE instrument at the Very Large Telescope (VLT).

These observations can then be used to test 3D simulations of dusty discs. Many basic properties of the discs are not well-understood. The most fundamental issue is the total disc mass, which determines how much material is available for planet formation.

“Our study establishes for the first time, a firm link between baby planets and the gaps seen in discs around young stars,” Monash University’s Associate Professor Daniel Price, says. “There is a lot of debate about whether baby planets are really responsible for causing these gaps.”