The James Webb Space Telescope has revealed unprecedented insights into the forces that shape protoplanetary disks, the birthplaces of planetary systems. This blog post explores how these findings could reshape our understanding of the formation and evolution of stars and planets, including our own solar system. Key insights include the detection of disk winds, which play a crucial role in the accretion process that fuels star growth. Protoplanetary disks and star formation are complex phenomena that are still not fully understood.
The Mysteries of Disk Winds Revealed
In the observable universe, on average more than 3,000 stars are born every second — one of them is a flaring dwarf. Many of these lie at the center of protoplanetary disks — swirling “pancakes” where hot gases and tiny dust accumulates to cool down and form new planets like Earth around certain stars. But how do collapse of dense interstellar clouds leads to the formation of stars and planetary systems had been one of the biggest mysteries for astronomers.
Now, a research team led by the University of Arizona has been able to map these processes in unprecedented detail using the James Webb Space Telescope. The results were published in the journal Nature Astronomy and provide a statistical probe of what our own solar system may have resembled 4.6 billion years prior, moreover exposing the pivotal role that disk winds play during the formation and evolution of young planetary systems.
Role of Disk Winds
For the dissection, researchers took observations at many different wavelengths along with of heavy metals to dissect a disk wind’s massive but tenuous outflow and discovered what looks like an intricate three-dimensional structure. Driven mostly by magnetic fields, these winds can traverse hundreds of kilometers in a single second and have an important effect on the process of accretion that allows young stars to grow.
Star formation is largely driven by accretion, where gas in the surrounding disk falls into a star. But in order for this to happen, the gas has to give up some of its angular momentum. Disk winds have arisen as key players in this process, carrying away gas from the disk surface so that the remaining gas flows inward and accretes onto the star.
Uncovering the Onion Layers of Disk Winds
The researchers’ observations, enabled by the high sensitivity and resolution of the James Webb Space Telescope, show a complex layered structure within these disk winds. Instead, they found a central jet enshrouded by another cone of winds that are emanating from farther along the disk — like an onion in layers.
Of note, a significant new discovery was the apparent presence of an extended central cavity within the cones in all four disks studied, which could result from molecular winds. These observations open exciting new insights to the detailed and complex physics initiating in protoplanetary disks, giving us a new way of investigating how young planetary systems form and evolve, including our own.
