Behemoth Star Destroys Potential Solar Systems
A blue giant in the Orion Nebula is blowing away dust clouds around nearby stars
By Christopher Crockett | Interim Astronomy Writer for Science News

MARCH 13, 2014 – 3:40 PM | A massive star in the Orion Nebula is obliterating some planet nurseries while sparing others. Measurements of the dust swirling around Orion’s young stars reveal a zone of destruction near the massive star, one of the brightest in the nebula. Yet despite the carnage, many more planet-building disks survive in the harsh environment near the bright star than expected, a finding that could help researchers determine where solar systems can thrive in our galaxy.

The Orion Nebula, about 1,300 light-years away, is one of the closest star-forming neighborhoods. The nebula’s proximity makes it an attractive laboratory for understanding how stars and planets are born. The nebula envelops the Trapezium Cluster, a bundle of blue behemoths known as O stars, some of which shine roughly 250,000 times as bright as the sun.

DUST BUSTER In the Orion Nebula, some dusty disks surrounding young stars, as seen in this artist’s rendition, survive despite their proximity to Theta1 Orionis C, the bright star shining in the background. Stars closer to the massive star have lost most of their dust.

C.R. O’DELL AND S.K. WONG/RICE UNIV., NASA

Astronomers have long suspected that solar systems cannot form near O stars, whose abundant ultraviolet light should erode nearby planet nurseries. Rita Mann, an astronomer at the Herzberg Institute of Astrophysics in Victoria, Canada, decided to test this idea. She and her colleagues used the Atacama Large Millimeter/submillimeter Array, or ALMA, telescope in Chile to, for the first time, measure the faint radiation emitted by interstellar dust in the disks orbiting 48 young stars in the nebula. The micrometer-sized dust particles, composed of silicon- and carbon-rich compounds, are thought to be the building blocks of planets.