Limestone world gobbled by planet-eating white dwarf

Shower of carbon crumbs points to existence of puzzling exoplanet

White Cliffs of Dover

An exoplanet torn apart by its dead sun might have been slathered in calcium carbonate, a mineral also found in the White Cliffs of Dover (pictured).

Immanuel Giel/Wikimedia Commons (CC BY-SA 3.0)

SAN DIEGO — A remote planet — the first with hints of a limestone shell — has been shredded by its dead sun, a new study suggests.