Protoplanetary disc’s spiral arms embrace young star
Swirling around the young star Elias 2-27 is a stunning spiral-shape pinwheel of dust. This striking feature, seen with the Atacama Large Millimetre/submillimetre Array (ALMA), is the product of density waves — gravitational perturbations in the star’s protoplanetary disc that produce sweeping arms reminiscent of a spiral galaxy, but on a much smaller scale.