N Behara

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White dwarfs represent the endpoint of stellar evolution for stars with initial masses between approximately 0.07 and 8-10, where is the mass of the Sun (more massive stars end their life as either black holes or neutron stars). The theory of stellar evolution predicts that the majority of white dwarfs have a core made of carbon and oxygen, which itself is(More)
  • Werner Rauch, P Dufour, J Liebert, G Fontaine, N Behara
  • 2008
We report the discovery of a new class of hydrogen-deficient stars: white dwarfs with an atmosphere primarily composed of carbon, with little or no trace of hydrogen or helium. Our analysis shows that the atmospheric parameters found for these stars do not fit satisfactorily in any of the currently known theories of post-asymptotic giant branch (AGB)(More)
White dwarfs represent the endpoint of stellar evolution for stars with initial masses between approximately 0.07 M ⊙ and 8-10 M ⊙ , where M ⊙ is the mass of the Sun (more massive stars end their life as either black holes or neutron stars). The theory of stellar evolution predicts that the majority of white dwarfs have a core made of carbon and oxygen,(More)
We present a detailed analysis of all the known Hot DQ white dwarfs in the Fourth Data Release of the Sloan Digital Sky Survey (SDSS) recently found to have carbon dominated atmospheres. Our spectroscopic and photometric analysis reveals that these objects all have effective temperatures between ∼ 18,000 and 24,000 K. The surface composition is found to be(More)
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