Biggest diamond in the universe?

Call it the ultimate Valentine. The core of a cooling white dwarf star 50 light-years from Earth is composed almost entirely of crystalline ...

Call it the ultimate Valentine. The core of a cooling white dwarf star 50 light-years from Earth is composed almost entirely of crystalline carbon, scientists say. In short, a giant diamond. In fact, according to an announcement from the Harvard-Smithsonian Center for Astrophysics, this white dwarf has a diameter of 2,500 miles and weighs 5 million trillion trillion pounds, or 10 billion trillion trillion carats. The largest gem-quality diamond yet found on Earth was the 3,106-carat ‘‘Cullinan’’ discovered in 1905. The 530-carat ‘‘Star of Africa’’ in the British crown jewels was cut from it.

‘‘The theory is that when dwarf stars get cool enough they begin to crystallise,’’ said centre astrophysicist Travis Metcalfe, head of the research. ‘‘The problem is that once they cool down they can’t store any heat at all, and they become impossible to detect.’’

This spectacular celestial body, 50 light-years away in the constellation Centaurus, bears the unspectacular name BPM 37093, but don’t be fooled: ‘‘It’s not exactly the same structure as diamond,’’ said University of Texas astronomer Don Winget. ‘‘But it’s real close.’’

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In research to be published in the Astrophysical Journal Letters, Metcalfe and co-authors Michael Montgomery of Britain’s University of Cambridge and Antonio Kanaan of Brazil’s Universidade Federal de Santa Catarina, say most regular stars—including the sun—will probably end their lives as white dwarves. ‘‘Eventually it will lose its shell of gases, leaving behind the hot white core.”

The process spans billions of years. Most known dwarves are smaller than the sun, but BPM 37093 is slightly larger and is the most massive known. The scientists said they had joked for years about how they might improve on the Taylor sisters’ famous 1806 poem Twinkle, Twinkle, Little Star. It isn’t ‘like a diamond in the sky, they say “it is a diamond in the sky.’’

-LAT-WP