Dust particles spotted around a young star support an idea about how planets are born.

Planet formation is a paradox: according to standard theory, dust grains orbiting newborn stars should spiral into those stars rather than accrete to form planets. Astronomers have suggested that there are regions, or 'pressure bumps', where density and pressure gradients trap particles long enough to allow them to clump together.

Credit: ESO/L. CALÇADA

A team led by Nienke van der Marel at Leiden University in the Netherlands has observed such a trap around the star Oph IRS 48 located about 120 parsecs from Earth. The Atacama Large Millimeter/submillimeter Array in Chile detected a crescent-shaped cluster on one side of the star — probably a reservoir of coalescing dust grains (pictured as an artist's impression).

Science 340, 1199–1202 (2013)