When Stars Attack

The idea that stars eat planets isn’t really new; combine an unstable planetary orbit with a star’s massive gravitational pull, and the outcome pretty much writes itself. It’s essentially a larger-scale version of what happens when a small meteor collides with Earth: the planet is pulled in, the star absorbs whatever made up the planet, and before long you’ve lost all evidence that the planet was ever there to begin with.

Well, all visual evidence, anyway. A recent study has documented the effect of the planet-eating process on the chemical composition of stars. And as the study’s authors (Vanderbilt University’s Trey Mack and Kevin Stassun) explain, there’s a lot this trace evidence can tell us about the composition of a solar system—past, present, and future:

[embed]https://www.youtube.com/watch?v=Ik8wjgCWk5U[/embed]

Earth’s orbit is extremely stable and the size of the Sun isn’t likely to change for a few billion years, so the likelihood that we’ll all become fondue is extremely low. What really makes this study useful is what it tells us about other solar systems—what they are (or were) made of, whether they contain (or once contained) earthlike planets, and so on. It’s a pretty morbid business, but as we prepare for the 2018 launch of the James Webb Space Telescope (JWST) and the possibility of studying a large number of new solar systems, the new Vanderbilt technique is likely to come in handy.