A study led by Paolo Padoan, ICREA research professor at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB), is challenging the understanding of planetary disk formation around young stars. The paper, published in Nature Astronomy, reveals that the environment plays a crucial role in determining the size and lifetime of these planetary disks, which are the sites of planet formation.
When a star forms, it is surrounded by a spinning disk of gas and dust. Over time, this material eventually forms the planets. Traditionally, scientists believed that once a disk forms, it simply loses too much over time as it feeds the star and the growing planets. However, Professor Paolo Padoan's study introduces a new perspective that shows that young stars actually gain too much from their surroundings through a process known as Bondi-Hoyle accretion. This process helps to re-accrete the disk, making it larger and more durable than previously thought.
"Stars are born in groups or clusters within large gas clouds and can remain in this environment for several million years after their birth", says Paolo Padoan, first author of the study and currently on leave at Dartmouth College (United States).
"After a star forms, its gravity can capture more material from the parental gas cloud, which is not enough to change the star's mass significantly but enough to restructure its disk. To understand what mass can attract a star with this Bondi-Hoyle accretion, and the spin and size of the disk induced by the new material, some fundamental properties of the chaotic motion of interstellar gas, known as turbulence, would have to be modelled and understood".
