Self-Destruct

This planet triggers flares on its star—spelling its ultimate doom

- Jacek Krywko

STARS OFTEN WHIP their planets with stellar winds and radiation, pull them ever closer with gravity and sear them with heat. But a newfound planet exerts an unexpectedly strong-and ultimately self-destructive-influence on its star in return.

The star, HIP 67522, is slightly larger than our sun and shines roughly 408 light-years away in the Scorpius-Centaurus association. It's 17 million years old, a youngster by stellar standards, and has two orbiting planets that are even younger. The innermost of these two planets, a Jupiter-size gas giant called HIP 67522 b, orbits HIP 67522 at a distance of less than 12 times the star's radius-about one-seventh Mercury's distance in solar radii from our own sun. This in-your-face proximity, combined with HIP 67522's volatile teenage nature, creates a spectacle that astronomers have never seen before: a planet that triggers powerful flares on the surface of its host star, leading to the planet's own slow destruction.