How fast does a white dwarf spin?

Answer 1

Since white dwarves concentrate a large part of the mass of the original star into a much smaller volume, the conservation of angular momentum should demand that they spin much faster than the original star did. However, observations of the surface layers of white dwarves show that they typically spin much slower. It is not known at this time whether it's just the surface spinning slowly, while the interior rotates more rapidly, or if the star has somehow managed to shed angular momentum during its evolution.