An international research team, led by Chin-Fei Lee at the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA, Taiwan), has detected a pair of spiral arms in an accretion disk around a protostar (baby star), using the Atacama Large Millimeter/submillimeter Array (ALMA). Interestingly, these spiral density enhancements make the disk appear like a “space whirlpool.” The finding not only supports current theories of accretion disk feeding processes, but also potentially brings key insights into the processes of grain growth and settling that are important to planet formation.
Source:
https://phys.org/news/2019-10-spiral-arms-young-accretion-disk.html