Astronomers Spot a Metal Scar on a Cannibal Star

Having grown up on a world orbiting a gentle yellow star, it is easy for humanity to forget the incredible destructive potential of the nuclear fusion powered monsters blazing at the heart of each and every planetary system.

Stars have the potential to scour nearby planets barren, or launch devastating outbursts of radiation at more distant worlds in the form of coronal mass ejections. In some extreme cases, they have even been known to tear large asteroids and planets asunder, and devour them in their entirety.

Evidence of one such act of cosmic cannibalism was recently discovered by a team of astronomers using the European Southern Observatory’s Very Large Telescope, who found evidence of a vast metallic scar marking the light fingerprint of an Earth-sized dying star known as a white dwarf.

According to the authors of the new study published in The Astrophysical Journal Letters, the metal mass likely represents the remains of a planetoid, or potentially an asteroid that would have been roughly 500 km-wide before it was shredded by the star’s disruptive gravitational influence. Fluctuations in the strength of the metallic signal suggests that the rocky debris are concentrated at select points on the star’s surface, which in turn indicates that the star’s magnetic field played a key role in the feeding process.

“Surprisingly, the material was not evenly mixed over the surface of the star, as predicted by theory. Instead, this scar is a concentrated patch of planetary material, held in place by the same magnetic field that has guided the infalling fragments,” said study co-author professor John Landstreet, of the Western University, in Canada, and the Armagh Observatory and Planetarium. “Nothing like this has been seen before.”

Starfield Tour of the Solar System

It is possible that Earth will also be consumed by its star after the Sun runs out of the hydrogen reserves fueling the fusion reaction raging at its heart, and begins its transformation into a red giant - a process that is expected to begin in some 5 billion years time. At this point, it will swell to a size that would see it swallow the innermost planets of the solar system, including Mercury, and Venus.

In the meantime, astronomers are using machines known as spectrographs to unravel the light fingerprints of distant stars in order to discover the compositions of these stellar giants, and the natures of the planetary material that they consume. For more cosmic news why not read about the discovery of the brightest object in the universe, or have an existential crisis about a corkscrew formation of galaxies that was recently found lurking in deep space.

Anthony is a freelance contributor covering science and video gaming news for IGN. He has over eight years experience of covering breaking developments in multiple scientific fields and absolutely no time for your shenanigans. Follow him on Twitter @BeardConGamer

Image credit: ESO