Planets can form under intense radiation

Nov. 19 () –

New observations of Atacama Large Millimeter/submillimeter Array (ALMA) suggest that planet formation can occur even in hostile stellar environments previously considered inhospitable.

An international team of astronomers used ALMA to capture High-resolution images of eight protoplanetary disks in the Sigma Orionis clusterwhich receives intense ultraviolet light from a nearby massive star. To their surprise, they found evidence of gaps and rings in most of the disks, structures commonly associated with the formation of giant planets, such as Jupiter.

“We expected that the high levels of radiation in this cluster would inhibit planet formation in the outer regions of these disks,” he said. in a statement lead author Jane Huang. “But instead, we are seeing signs that planets may be forming at distances of tens of astronomical units from their stars, similar to what we have observed in less hostile environments.

Previous studies had focused on disks in regions with low ultraviolet radiation. This new research provides ALMA’s highest-resolution look at disks in a more extreme environment. “These observations suggest that the processes driving planet formation are quite robust and can operate even under difficult circumstances,” Huang said. “This gives us more confidence that planets may be forming in even more places throughout the galaxy, even in regions that we previously thought were too harsh.

The findings have implications for understanding the formation of our own Solar System, which likely evolved in a similar high-radiation environment. They also motivate future studies of disks in even more extreme stellar neighborhoods.

The research team used ALMA’s most extended antenna configuration to obtain unprecedented detail in its disk images, achieving a resolution of about 8 astronomical units. This allowed them to resolve multiple gaps and different rings in several of the disks.. While the exact nature of these disk structures is still debated, they are believed to be conducive to planet formation or a consequence of interactions between the forming planets and the disk material.

This study demonstrates the power of ALMA to investigate planet formation in diverse environments across the galaxy. As astronomers build a more complete picture of how planets form under different conditions, they get closer to understanding the origins of Earth and the prevalence of planets around other stars.

This research was published in the Astrophysical Journal.