BPM 37093 is a white dwarf star 50 light-years from Earth, in the constellation Centaurus, for which enough evidence has been gathered to infer that it consists of crystalline carbon, confirming previous theoretical predictions. It is estimated that the decayed star's core contains a 10 decillion (1×10³⁴) carat (2 septillion tonne) diamond, approximately 4,000 km (2,500 miles) in diameter.

Researchers at Harvard University announced this discovery February 13, 2004. As a solid object, it exhibits "ringing" which was detected by the researchers. The object is thought to be an example of one of the stages of stellar evolution; in this case, as the stellar material of BPM 37093 was consumed by thermonuclear reactions (probably the triple-alpha process), the resultant "ash" is carbon at enormous pressure. "A teaspoon-sized, white dwarf diamond, will weigh five tonnes" [1]. Carbon maybe, but with that density it would not be diamond. Astronomers like to have a bit of fun.

As a common name the discoverers humorously entitled it Lucy after The Beatles' hit Lucy in the Sky with Diamonds.

External links

• BBC News: Diamond star thrills astronomers
• Harvard-Smithsonian Center for Astrophysics, press release