Magnetism could help explain mystery of planet-forming disks

Astronomers have said that magnetic storms in the gas orbiting young stars could help explain a mystery that has persisted since before 2006.

Researchers using NASA's Spitzer Space Telescope to study developing stars have had a hard time figuring out why the stars give off more infrared light than expected.

The planet-forming disks that circle the young stars are heated by starlight and glow with infrared light, but Spitzer detected additional infrared light coming from an unknown source.

A new theory, based on three-dimensional models of planet-forming disks, suggests the answer: Gas and dust suspended above the disks on gigantic magnetic loops like those seen on the Sun absorb the starlight and glow with infrared light.

Neal Turner of NASA's Jet Propulsion Laboratory, Pasadena, California said that if one could somehow stand on one of these planet-forming disks and look at the star in the center through the disk atmosphere, they would see what looks like a sunset.

The new models better describe how planet-forming material around stars is stirred up, making its way into future planets, asteroids and comets.

The new work brings these pieces together by calculating how the starlight falls across the disk and its fuzzy atmosphere. The result is that the atmosphere absorbs and re-radiates enough to account for all the extra infrared light.