BPM 37093 A relatively close white dwarf star located in the constellation Centaurus. It consists of a thin hydrogen atmosphere overlying a Moon-sized carbon core in which the atoms are believed to have been pushed so close together by gravitational pressure that they have stripped each other's electrons from around their positively charged nuclei and the mutual repulsion between the nuclei has forced them into a crystalline lattice structure. In February 2004 scientists at the Harvard-Smithsonian Center for Astrophysics announced that their recent investigations of the star had confirmed BPM 37093 to be a crystalline white dwarf, the first such object to be detected, The detection gave tangible proof to a theory advanced independently by Kirzhnitz (1960), Abrikosov (1960), and Salpeter (1961) that cool white dwarfs might crystallize. BPM 37093 is a pulsating star, and measurements of the pulsations indicate that the interior of the white dwarf is indeed solid crystalline carbon. Since BPM 37093 is effectively a vast cosmic diamond, it has been unofficially nicknamed ‘Lucy’, in recollection of the Beatles' song ‘Lucy in the sky with diamonds'. mv : 13; spectral type: DA V; diameter: about 4000 km; mass: 1.14 times solar mass; distance: 15.3 pc.