Disintegrating stars can destroy planets, Harvard scientist finds

A Harvard astrophysicist is ready to set the record straight — death stars may not merely be fictitious weapons from the classic Star Wars franchise. Disintegrating stars, known as white dwarves, can in fact destroy entire planets, and it’s more common than we think.

Andrew Vanderburg, a graduate student at the Harvard-Smithsonian Center for Astrophysics, first made the discovery in March while analyzing data from the Kepler Spacecraft, which surveys different areas of the sky every 80 days.

After noticing an unusual signal in the data from the summer of 2014, Vanderburg focused on a white dwarf in the Virgo constellation and began examining it from ground-based telescopes. His findings were published Wednesday in the scientific journal Nature.


From the ground, Vanderburg discovered the cause of the signal — the gravitational pull and intense heat from the cooling white dwarf was disintegrating a nearby planet into fragmented pieces. In other words, the dead star was destroying its own planet.

“We’ve caught a star in the act of destroying a planet in its own system,” he said. “It’s like the smoking gun.”

Researchers have long believed white dwarves could develop destructive abilities. However, Vanderburg said, the new observations from Kepler — which was launched by NASA in 2009 — have allowed astrophysicists to see a destructive white dwarf in action for the first time.

Astrophysicists believe that 25 to 35 percent of all white dwarves destroy nearby planets in this way, Vanderburg said. And the destruction of a planet by a white dwarf is something Vanderburg predicts will happen to most solar systems.

In our own solar system, the sun is expected to run out of fuel in 5 to 7 billion years, and will become a white dwarf that could engulf the Earth as it expands, he said.

If the Earth withstands the sun’s expansion, it could disintegrate in the same way Vanderburg’s research portrayed.


“We think this is something that’s probably happening around many many stars,” he said. “This is just the first example of us catching it in the act.”

Vanderburg said he hopes his research will add to the understanding of the makeup of planets. The size of the dust particles and the elements being fragmented by the white dwarf could provide telling insights, he said.

“We get this chance to watch a planet being disassembled,” he said. “We should take the chance and see what we can find.”

Felicia Gans can be reached at felicia.gans@globe.com. Follow her on Twitter @FeliciaGans.