author={S. Rappaport and P. Podsiadlowski and I. Horev},
  journal={The Astrophysical Journal},
We show how the recent discovery of a likely close white dwarf companion to the well-known star Regulus, one of the brightest stars in the sky, leads to considerable insight into the prior evolutionary history of this star, including the cause of its current rapid rotation. We infer a relatively narrow range for the initial masses of the progenitor system: M 10 = 2.3 ± 0.2 M ☉ and M 20 = 1.7 ± 0.2 M ☉, where M 10 and M 20 are the initial masses of the progenitors of the white dwarf and Regulus… Expand

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