Astronomers detected two small planets (in the range of Earth) circling a white dwarf (Kepler-20) in close proximity (Nature 480, 460 f and 496 ff). This discovery is remarkable, since these planets seem to be remnants of planetary bodies once swallowed by a red giant, which preceeded the white dwarf in the evolution of this planetary system. The following animation gives a short summary of the assumed events…
Planetary sun bath
The system observed, which contains further larger planets in greater distance from the star as well, seems to have formed from a system similar to our own solar system, with some larger planets circling around a sun-like star. When this star transformed into a red giant some of the planets were swallowed up. Unexpectedly their remnants became liberated again (with changed orbits and composition) when the red star lost its outer shell and became a white dwarf.