When a star like our sun reaches the end of its life, it can ingest the surrounding planets and asteroids that were born with it. Now, using the European Southern Observatory's Very Large Telescope (ESO's VLT) in Chile, researchers have found a unique signature of this process for the first time—a scar imprinted on the surface of a white dwarf star. The results are published in The Astrophysical Journal Letters.

"It is well known that some white dwarfs—slowly cooling embers of stars like our sun—are cannibalizing pieces of their planetary systems. Now we have discovered that the star's magnetic field plays a key role in this process, resulting in a scar on the white dwarf's surface," says Stefano Bagnulo, an astronomer at Armagh Observatory and Planetarium in Northern Ireland, UK, and lead author of the study.