ALMA spies a new planetary nursery

This image from the Atacama Large Millimeter/submillimeter Array (ALMA) shows MWC 758, a young star that is approaching adulthood and surrounded by knotty, irregular rings of cosmic dust, three of which can be seen here. Unusually, these rings are elliptical in shape rather than being perfectly circular — making this the first discovery of an intrinsically elliptical protoplanetary disc with ALMA!

The outer and inner rings each contain one particularly bright clump, visible as arcs of yellow. Additionally there appear to be spiral arms traced out within the dust, as well as a core dust-free cavity that is slightly off-centre. These are all features that hint at the presence of unseen planets. As planets form, they gravitationally interact with the disc and create various telltale features and structures. Astronomers can thus observe a system like MWC 758 and not only infer the existence of potential hidden planets, but also estimate their masses, locations, and orbits.

This is a wonderful example of the planet-finding power of ALMA. Using the observatory to study such dusty discs allows scientists to investigate the very first stages of planet formation in a bid to understand how these infant systems form and evolve. Learning more about planetary systems throughout the cosmos may help us know more about how the Solar System formed, and how it evolved to become the cosmic home we live in today.