‘Diamond’ Planet Found Orbiting Dead Star

Scientists discovered a planet 20 times denser than Jupiter that they say has the chemical composition, pressure and dimensions to suggest a crystalline, or diamond, makeup.

The planet’s density implies it’s made of carbon and oxygen, rather than hydrogen and helium, which are the main components of gaseous planets like Jupiter, according to a report published online yesterday by the journal Science.

The planet was discovered orbiting a dead star spinning hundreds of times a second. The finding may shed light on this class of neutron stars, called millisecond pulsars, thought to be the leftovers of stellar explosions, said researchers led by Matthew Bailes, a professor at Swinburne University of Technology in Australia.

While 30 percent of these pulsars are discovered alone, most evolve with companions that in special circumstances can be “transformed into exotic planets unlike those likely to be found anywhere else in the universe,” the researchers wrote.

The researchers spotted the planet and its millisecond pulsar using the Parkes radio telescope in New South Wales, Australia.

To contact the reporter on this story: Meg Tirrell in New York at mtirrell@bloomberg.net.

To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net.