How we understand our universe is a constant back and forth between theorists and observationalists. On one side, brilliant teams of theorists combine math and software to model how things in our universe should change with time, based on all the physics they can recognize needs to be included. Then, equally brilliant teams of observers use engineering and software to measure what is actually going on as well as they can, and more often than not, they discover things are similar but not identical to those models, and more physics is needed in those models.

In recent years, observers using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope have been able to observe massive dust disks around young stars and the formation of planets in those disks. Looked at quickly, all is as it should be, but if you look closely, it becomes apparent those disks are way larger than anyone expected. It just hadn’t been believed that young solar systems would have dust at large distances.

So, it’s time to fix the models.

A team at the National Astronomical Observatory of Japan and including members at  Kagoshima University used the ATERUI II supercomputer to make the first-ever models to look at dust motion in a growing disk around a star with gas outflows. This allowed them to follow the dust as it got caught up in the stellar jets and then rained down in the outskirts of the model solar system. This work was led by Yusake Tsukamoto, who commented: Living in Kagoshima, in the shadow of the active volcano Mt. Sakurajima, I naturally thought of volcanic ashfall when I saw the simulation results.

And just as ash can create a fertile landscape, this ash seems to make solar systems ready to birth far-out worlds.

More Information

NAOJ press release

“‘Ashfall’ Induced by Molecular Outflow in Protostar Evolution,” Yusuke Tsukamoto, Masahiro N. Machida, and Shu-ichiro Inutsuka, 2021 October 15, The Astrophysical Journal Letters