BPM 37093

Structure

In the 1960s, it was predicted that as a white dwarf cools, its material should crystallize, starting at the center. When a star pulsates, observing its pulsations gives information about its structure. BPM 37093 was first observed to be a pulsating variable in 1992, and in 1995 it was pointed out that this yielded a potential test of the crystallization theory. In 2004, Antonio Kanaan and a team of researchers of the Whole Earth Telescope estimated, on the basis of these asteroseismological observations, that approximately 90% of the mass of BPM 37093 had crystallized. Other work gives a crystallized mass fraction of between 32% and 82%. Any of these estimates would result in a total crystalline mass in excess of 5 kilograms. As the white dwarf has a radius of 2500 mi, this means that the core of BPM 37093, nicknamed Lucy, is likely one of the largest diamonds in the local region of the universe.

Crystallization of the material of a white dwarf of this type is thought to result in a body-centered cubic lattice of carbon and/or oxygen nuclei, which are surrounded by a Fermi sea of electrons.

Nickname and press coverage

• Since a diamond also consists of crystallized carbon, the star BPM 37093 has been nicknamed Lucy after the Beatles' hit Lucy in the Sky with Diamonds.

In popular culture

• In John C. Wright's science fiction novel Count to a Trillion and its sequels, V886 Centauri is called the "Diamond Star", after the crystalline carbon core. In the story of the novel, it becomes the destination of the first human interstellar journey after it is discovered that the star, a ten-decillion-carat diamond of degenerate matter, is not matter at all, but antimatter. An alien artifact called "The Monument" is found orbiting it, which increases human knowledge of mathematics immensely.
• In Jim Jarmusch's 2013 film Only Lovers Left Alive, Tilda Swinton's character Eve tells Tom Hiddleston's character Adam about BPM 37093, describing it as a "diamond up there the size of a planet" that "emits the music of a gigantic gong".

References

References

1. [http://adsabs.harvard.edu/abs/1999ApJS..121....1M A Catalog of Spectroscopically Identified White Dwarfs] {{Webarchive. link. (2018-08-08 , George P. McCook and Edward M. Sion, ''Astrophysical Journal Supplement'' '''121''', #1 (March 1999), pp. 1–130. [[Centre de Données astronomiques de Strasbourg). CDS]] ID [http://cdsarc.u-strasbg.fr/viz-bin/Cat?III/210 III/210] {{Webarchive. link. (2013-10-22 .)
2. "This Valentine's Day, Give The Woman Who Has Everything The Galaxy's Largest Diamond". Center for Astrophysics.
3. Crystallization of carbon-oxygen mixtures in white dwarfs, J. L. Barrat, J. P. Hansen, and R. Mochkovitch, ''Astronomy and Astrophysics'' '''199''', #1–2 (June 1988), pp. L15–L18. {{bibcode. 1988A&A...199L..15B
4. Córsico, Alejandro H.. (2019-12-01). "Asteroseismological analysis of the ultra-massive ZZ Ceti stars BPM 37093, GD 518, and SDSS J0840+5222". Astronomy & Astrophysics.
5. "WG 22".
6. {{Cite Gaia DR3. 6127333286605955072
7. (10 March 1992). "The Discovery of a New DAV Star Using IUE Temperature Determination". The Astrophysical Journal.
8. [http://spiff.rit.edu/classes/phys230/lectures/planneb/planneb.html Late stages of evolution for low-mass stars] {{Webarchive. link. (2020-06-11 , Michael Richmond, lecture notes, Physics 230, [[Rochester Institute of Technology]], accessed online May 3, 2007.)
9. Testing White Dwarf Crystallization Theory with Asteroseismology of the Massive Pulsating DA Star BPM 37093, T. S. Metcalfe, M. H. Montgomery, and A. Kanaan, ''Astrophysical Journal'' '''605''', #2 (April 2004), pp. L133–L136. {{bibcode. 2004ApJ...605L.133M
10. The Status of White Dwarf Asteroseismology and a Glimpse of the Road Ahead, D. E. Winget, ''Baltic Astronomy'' '''4''' (1995), pp. 129–136. {{bibcode. 1995BaltA...4..129W
11. Whole Earth Telescope observations of BPM 37093: a seismological test of crystallization theory in white dwarfs, A. Kanaan, A. Nitta, D. E. Winget, S. O. Kepler, M. H. Montgomery, T. S. Metcalfe, et al., ''Astronomy and Astrophysics'' '''432''', #1 (March 2005), pp. 219–224. {{bibcode. 2005A&A...432..219K {{doi. 10.1051/0004-6361:20041125.
12. (16 February 2004). "BBC News: Diamond star thrills astronomers".
13. P. Brassard, G. Fontaine, Asteroseismology of the Crystallized ZZ Ceti Star BPM 37093: A Different View, ''Astrophysical Journal'' '''622''', #1, pp. 572–576. {{bibcode. 2005ApJ...622..572B
14. (12 June 2014). "Lucy's in the Sky with Diamonds: Meet the Most Expensive Star Ever Found". Futurism.