Something very strange is happening around the star KIC 12557548. Its light dims every 15 hours, as though a planet is orbiting around it…except the dimming varies wildly each time around. A planet is being vaporized before our eyes.
According to researchers led by Saul Rappaport of MIT, the star’s orbital companion is a rocky planet about twice the mass of Mercury orbiting at just a hundredth the distance between the Sun and Earth, a distance known as an astronomical unit (AU). For the sake of comparison, Mercury even at its closest approach to is always at least 0.3 AU from the Sun. At such a tiny distance, this planet would roast at 2,000 Kelvin, which would easily be hot enough to vaporize the common minerals that make up rocky planets.