Star BPM 37093 is now officially a girlâs bestest-estest. Friend. Evah. The Harvard-Smithsonian Center for Astrophysics has announced that this heavenly body, situated some fifty light years away as part of the constellation Centaurus, is in fact a mass of crystallised carbon. That is to say, BPM 37093 is now the biggest known diamond in the galaxy.
Scientists have renamed it âLucyâ â after comedian Peter Cookâs daughter, of whom John Lennonâs son Julian painted a portrait, depicting her in the sky, with diamonds. Oh, the scientist would be citing the song that John Lennon wrote, inspired by that painting, âLucy in the Sky with Diamondsâ, located on the album Sgt Pepperâs Lonely Hearts Club Band, and long believed to be both tribute to and proof of Lennonâs experience with LSD (lysergic acid diethylamide). A substance, you may consider for just a moment, that may have also given rise to scientists believing there are huge gemstones in outer space. Perhaps Mars is a great big ruby, and Venus, a hunk of gold? (Thatâs just silly; everyone knows Venus and Mars are billiard balls!)
With an estimated diameter of 2500 miles (4000km), Lucy is thought to weigh around 10 billion trillion trillion carats â ie 10,000,000,000,000,000,000,000,000,000,000,000 carats â or some 2,000,000,000,000,000,000,000,000,000 tonnes, give-or-take. âYou would need a jewellerâs loupe the size of the sun to grade this diamond,â said Travis Metcalfe, the astronomer from the Havard-Smithsonian Center for Astrophysics who led the team that discovered the interstellar gem. âImagine trying to construct one â youâd most likely fall on your lens grinding machine and make a spectacle of yourself,â he might have added, had he been a Groucho Marx fan.
The diamond, naturally, is mostly carbon, coated by a thin layer of hydrogen and helium gases. It was formed by the crystallisation of a white dwarf â which itself is the hot core that remains of a star after it has used up all of its fuel (like the embers of a fire, I guess, except, since they donât crystallise, once the fuel runs out, they become solid, unburnt carbon â more like graphite rather than diamond.)
Turns out astronomers have thought that the interiors of white dwarfs crystallised for more than four decades, but the ability to determine if this was the case only became possible recently. The white dwarf radiates not only light, but also sound, ringing âlike a gigantic pulsating gongâ, apparently. (So thatâs what the constellation Orion is doing â itâs not the hunter at all, but a huge J. Arthur Rank gong-ringer!)
By measuring the pulsations, scientists were able to study the interior of the white dwarf in the same way geologists study the earthâs interior by measuring the pulses of earthquakes with a seismograph.
âWe figured out that the carbon interior of this white dwarf has solidified to form the galaxyâs largest diamond,â says Metcalfe.
This raises some important issues â like should the Seven Dwarfs sign up for those space flights that have now become available? âHi-ho, hi-ho, itâs into space we goâ for the biggest diamond so far located in the known universe must make better sense than chipping away in the diamond mine day-in, day-out. Maybe they can get Mitsubishi to sponsor their trip (because âMitsubishiâ means âthree diamondsâ).
And, if scientists have only just determined that thereâs a star made entirely of diamond after four decades of suspicion, how did Jane Taylor know that a star could be exactly âlike a diamond, in the skyâ when she wrote the lyrics to âTwinkle, Twinkle, Little Starâ back in 1806?
What about our own nearest star, the sun? Why have we been lumbered with a so-called âmass of incandescent gasâ when other solar systems appear to be sporting bling? Fear not. Look forward to our own sun becoming a white dwarf when it dies. How long will that take? Astronomers reckon about 5 billion years. And a couple of billion years later, the core should crystallise to form a giant diamond. Until then, would Sir be interested in some cubic zirconia just beyond Pluto?
Meanwhile, the biggest problem facing the massive diamond in our galaxy is making the most of it. How the hell are we supposed to mount it onto one of those rings of Saturn?