An Isolated White Dwarf with a 70 s Spin Period

  title={An Isolated White Dwarf with a 70 s Spin Period},
  author={Mukremin Kilic and Alekzander Kosakowski and Adam Moss and Pierre Bergeron and Annamarie A. Conly},
  journal={The Astrophysical Journal Letters},
We report the discovery of an isolated white dwarf with a spin period of 70 s. We obtained high-speed photometry of three ultramassive white dwarfs within 100 pc and discovered significant variability in one. SDSS J221141.80+113604.4 is a 1.27 M ⊙ (assuming a CO core) magnetic white dwarf that shows 2.9% brightness variations in the BG40 filter with a 70.32 ± 0.04 s period, becoming the fastest spinning isolated white dwarf currently known. A detailed model atmosphere analysis shows that it has… 

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