SDSS J1240+6710

SDSSJ1240+6710 or SDSS J124043.01+671034.68, nicknamed Dox by its discoverers,[1] is a white dwarf with an atmosphere of almost pure oxygen discovered by Kepler de Souza Oliveira, Detlev Koester and Gustavo Ourique.[2][1][3] The atmosphere also has a detectable amount of magnesium, neon (under 4%) and silicon, but no hydrogen, helium or carbon. A possible explanation for the unusual composition would be if its mass were close to the limit for collapsing to a neutron star.[4] But its mass is only 0.56 solar masses, below the mass expected for a star that could convert carbon to oxygen, neon and magnesium.[5]

The star was originally catalogued in the catalogue of new white dwarf stars from the Data Release 12 of the Sloan Digital Sky Survey.[6][7] Gustavo Ourique, an undergraduate in Physics at Universidade Federal do Rio Grande do Sul, identified the star's unique spectrum, working under the advice of Dr. Kepler Oliveira (S.O. Kepler). The star's spectrum was modeled by Dr. Detlev Koester, characterizing its composition, temperature and mass.

References
  1. Herkewitz, William (31 March 2016). "Newly Discovered Star Has an Almost Pure Oxygen Atmosphere". Popular Mechanics.
  2. Kepler, S. O.; Koester, D.; Ourique, G. (31 March 2016). "A white dwarf with an oxygen atmosphere". Science. 352 (6281): 67–69. Bibcode:2016Sci...352...67K. doi:10.1126/science.aad6705. PMID 27034367.
  3. Gänsicke, Boris (1 April 2016). "An odd one out". Science.
  4. Hummel, Philipp (30 March 2016). "Weißer Zwerg im Sauerstoff" (in German). Retrieved 1 April 2016.
  5. "Witte dwergster vertoont een ongewone zuurstofatmosfeer" (in Dutch). 31 March 2016. Retrieved 1 April 2016.
  6. Kepler, S. O.; Pelisoli, I.; Koester, D.; Ourique, G.; Romero, A. D.; Reindl, N.; Kleinman, S. J.; Eisenstein, D. J.; Valois, A. D. M.; Amaral, L. A. (30 November 2015). "New white dwarf and subdwarf stars in the Sloan Digital Sky Survey Data Release 12". Monthly Notices of the Royal Astronomical Society. 455 (4): 3413–3423. arXiv:1510.08409. Bibcode:2016MNRAS.455.3413K. doi:10.1093/mnras/stv2526. hdl:10183/140429. Retrieved 1 April 2016.
  7. Grush, Loren (31 March 2016). "Astronomers spot a never-before-seen type of white dwarf star". The Verge. Retrieved 1 April 2016.


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