Infant worlds carve gaps in planet-forming disk

Dark rings in a disk of gas and dust encircle a young star in the clearest image yet of an infant planetary system. Astronomers suspect that the rings are carved out by planet embryos that sweep up material as they loop around their sun.

The disk encircles HL Tau, a 1-million-year-old star about 450 light-years away in the constellation Taurus. Researchers captured the image with the Atacama Large Millimeter/submillimeter Array, a network of several dozen radio dishes in northern Chile. The dishes, spaced up to 16 kilometers apart, allow astronomers to capture incredibly fine detail such as the thin grooves in a planet-forming disk.

Hints of gaps have been seen before, but this is the sharpest image of them to date. Observations of planet nurseries such as this one can help astronomers figure out how planetary systems — including our own — form.

Editor’s Note: This article was updated November 11, 2014, to correct the maximum distance between ALMA’s radio dishes. It is 16 kilometers, not 15.