Mass versus equatorial radius of rotating ¹²C white dwarfs (Boshkayev et al. 2013). The solid black curves correspond to J = constant sequences, where the static case J = 0 is the thickest one. The colored thin dashed curves correspond to P = constant sequences. The Keplerian sequence is the red thick dashed curve, the blue thick dotted-dashed curve is the inverse β instability boundary, and the green thick dotted curve is the axisymmetric instability line. The orange and purple dashed boundaries correspond to the pycnonuclear C+C fusion densities with reaction mean times τ_pyc = 10 Gyr and 0.1 Myr, respectively. The gray-shaded region is the stability region of rotating white dwarfs.