Spying a planet in star's dusty veil

To examine the dust disk encircling a young star 330 light-years away, scientists at the University of Arizona in Tucson used an emerging technique called nulling interferometry to block out the star's light. When they looked further, they found clues suggesting that a large gaseous planet was forming near the star, designated HD 100546.

Astronomers are eager to study the disruptions in dust disks to determine how our own planetary system evolved. However, the star's brightness overwhelms the thermal emissions from surrounding dust, making it all but invisible.

Wilson M. Liu and his colleagues adjusted the Magellan I telescope in La Serena, Chile, to record two sets of wavelengths from HD 100546–one offset by exactly one-half a wavelength from the other. This caused the crests and the troughs of the emissions from the star to negate each other, dimming the star's light and giving the astronomers a relatively unobstructed view of infrared emissions from the surroun