'Diamond planet' orbits nearby star

Astronomers have seen a flood of newly discovered planets in the past few years as new engineering tools for detecting these distant objects have been steadily refined. But to this point, most of these planets have fit nicely within the molds established in the solar system.

Researchers at Yale University seem to have broken this trend, after a team announced the discovery of what can only be described as a diamond planet.
The new discovery is one among five planets orbiting the relatively nearby - 40 light years -star of 55 Cancri in the constellation Cancer.

The planet, 55 Cancri e, had previously been identified and its mass estimated at around eight times that of Earth. But it was first directly observed last year, giving researchers the chance to measure its radius, which came out around twice that of Earth.

Star composition is much easier to pin down from afar and the team had already established it was extremely high in carbon and low in oxygen, suggesting that the surrounding planets would probably be short of water ice and certain other components.
"Stars are simple — given a star's mass and age, you know its basic structure and history," David Spergel, professor of astronomy and chair of astrophysical sciences at Princeton University, explained to Yale News. "Planets are much more complex."

The researchers were already aware that 55 Cancri e was very unlike Earth, with an orbit of only 18 hours around the sun. Surface temperatures are estimated to run as high as 3,900 degrees Fahrenheit.
Still, with the latest bits of information, the Yale team were able to put together a projection of the planet's composition - mostly carbon, iron, silicon carbide and some silicates.

"This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth," said Nikku Madhusudhan, a Yale postdoctoral researcher and the lead researcher on the project. "The surface of this planet is likely covered in graphite and diamond rather than water and granite."
As much as one-third of the planet's total mass is estimated to be diamond. That amounts to nearly three times Earth's mass, just in diamond.

As much as a glittering gem in the night sky might seem fascinating, the research leads to the bigger revelation that some of the more exotic planet types imagined by scientists could realistically exist.
"This ‘diamond-rich super-Earth’ is likely just one example of the rich sets of discoveries that await us as we begin to explore planets around nearby stars," Spergel suggested.