PSR J1719-1438 Is a Girl's Best Friend

One of its planets is, anyway. PSR J1719-1438 is the name given to a pulsar about 4,000 light years from Earth. Pulsars are a special kind of neutron stars that give off radio pulses, which appear to blink on and off to us as the star rotates and the radio source is aimed towards us and then away from us. Astronomers use those regular emissions to measure things and learn stuff about its immediate neighborhood.

But it seemed that PSR J1719-1438's pulses were regularly disturbed -- at certain times they were just a tick off. Astronomers thought that the most likely explanation was a planet orbiting the pulsar, and when they measured the pattern of interruptions, it let them figure out how fast the planet was moving, how far away it was from the pulsar and how big it was. The answers were eyebrow-raisers, because the measurements showed the planet was probably made of carbon and supremely dense. The combination meant its structure was most likely crystalline in nature, and crystalline carbon usually goes by the more familiar name "diamond." Yup -- pulsar PSR J1719-1438's got a big ol' hunk of engagement ice orbiting around it.

Neutron stars are collapsed old stars that have burned up their fuel but weren't big enough to go nova. Scientists figure its pricy companion was probably a white dwarf star that had all of its outer atmosphere stripped away by the pulsar. White dwarf stars are also small stars. They don't reach the size necessary to produce heavier elements in their nuclear furnaces, stopping at carbon. When the pulsar ripped off the hydrogen-helium atmosphere of the white dwarf, a dense carbon core was left and its own gravity compressed it into the diamond structure. The astronomers say it's even denser than any Earth diamond, meaning it would be much harder and would weigh more than an Earth diamond of the same size.

Astrophysicist Marc Kuchner theorized the existence of carbon or diamond planets. But he thought they would form sort of like planets regularly form, through gradual clumping together in a protoplanetary dust disk, only in a disk that was carbon-rich and oxygen-poor. Kuchner's hypothesis didn't cover the white dwarf scenario.

In any event, the system is, as I mentioned, some 4,000 light years away, meaning the fastest spacecraft we have on the planet would take hundreds of thousands of years to get there and return. Which means, 1) you've still got time to sell your DeBeers stock before the bottom falls out of the diamond market and 2), It's gonna be awhile before the price of those things goes down -- tough luck, fellas.