Planets as Brake Pads

This set of artist’s illustrations demonstrates how a dusty planet-forming disk can slow down a whirling young star, essentially saving the star from spinning itself to death. Evidence for this phenomenon comes from NASA’s Spitzer Space Telescope.
Credit: NASA/JPL – Caltech/R. Hurt (SSC)



"We knew that something must be keeping the stars’ speed in check," said Dr. Luisa Rebull of NASA’s Spitzer Science Center, Pasadena, Calif. "Disks were the most logical answer, but we had to wait for Spitzer to see the disks."



Developing stars spin so fast that, left unchecked, they would never fully contract and become stars. Prior to the new study, astronomers had theorized that disks might be slowing the super speedy stars by yanking on their magnetic fields. When a star’s fields pass through a disk, they are thought to get bogged down like a spoon in molasses. This locks a star’s rotation to the slower-turning disk, so the shrinking star can’t spin faster.




Other factors that contribute to a star’s winding down over longer periods of time include stellar winds and possibly full-grown planets.

This artist’s concept shows a dusty planet-forming disk in orbit around a whirling young star. NASA’s Spitzer Space Telescope found evidence that disks like this one can slow their stars down, which prevents the stars from spinning themselves to death.





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FUSEing Carbon Planets
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Decoding Dusty Disks
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