“Twinkle, twinkle little star/ how I wonder what you are/ up above the world so high/ like a diamond in the sky…”
Countless parents have sung that classic song with their small children without too much thought to the words, but astronomers have discovered a star is not just like a diamond in the sky.
They did more than wonder what it was, and they have an answer. The star known as BPM 37093 (aka V886 Centauri) is, in fact, an actual diamond the size of a planet. Neither of its official names are particularly memorable, so scientists have given it a third name – Lucy, after the Beatles’ song Lucy in the Sky with Diamonds.
What Is the Stars? What Is the Stars?
Joxer in Sean O’Casey’s play Juno and the Paycock wasn’t the only Irishman to wonder “what is the stars, what is the stars”. Just a few years after O’Casey penned the play, William Hunter O’Crea completed a PhD at Cambridge that included calculations demonstrating that the sun was hydrogen and helium with traces of other elements. McCrea’s work laid the foundation for how we understand the formation of the solar system and the nature of the sun itself, which is of course a star.
While the stars we see above us at night are the same ones that shone above our ancestors throughout the ancient world, these glorious balls of light do have a life cycle. As the gases of the star burn up, its light fades, leaving its core, which is comprised mainly of carbon and oxygen. When a star dies, the remaining core is still hot. Astronomers call this a white dwarf star, and they theorized that the core of such a star eventually crystalizes.
Lucy, the Diamond in the Sky
Lucy, a white dwarf star 50 light years away from the Earth in the constellation of Centaurus, captured the attention of astronomers. The star’s temperature had dropped below 12,000 degrees Fahrenheit, and Lucy was pulsating and chiming like an enormous gong.
A team of researchers decided that Lucy was an ideal opportunity to use new technology to confirm the theory that white dwarf stars crystalize, and they discovered that Lucy was 90% crystalized. And crystalized carbon is diamond.
While stars do eventually burn out and die, diamonds are forever. At 4,000 kilometres across, Lucy tips in at 10 billion trillion trillion carats. (No, that is not a typo. It’s 10 billion trillion trillion carats.) This dwarf white star really dwarfs the 546-carat Golden Jubilee diamond and the famous Hope diamond, which was originally 115 carats. Lucy is far enough out of our reach to be safe from humans, which means we can all enjoy looking up at night and wondering if we can spot it. (Tip: It’s best seen from Florida in the month of May.) Whether we have a collection of diamonds to rival a royal or one diamond engagement ring, the stars are a treasure for everyone.
All of this begs the question – how many of those twinkling stars above us really are diamonds?