Spin separates giant planets from ‘failed stars’
For decades, astronomers have struggled to differentiate giant planets from brown dwarfs, a class of objects more massive than planets but too small to ignite nuclear fusion like true stars.
Through a telescope, these cosmic lookalikes can have the overlapping brightness, temperatures and even atmospheric fingerprints. The striking similarity leaves astronomers unsure if they have observed an oversized planet or an undersized star.
Now, a Northwestern University-led team has uncovered a crucial clue that separates the two: how fast they spin.
In a new study, astrophysicists found the clearest evidence ...