Energy production in low mass white dwarf stars.

[Dr Paul Leyland]

Here it is: https://ui.adsabs.harvard.edu/abs/1997ApJ…482..420L/abstract

Hydrogen burning continues in the fully convective body of a low mass white dwarf until the temperature drops below 2000K.

White dwarfs in binary systems very often undergo hydrogen fusion. The BAA-VSS observes them all the time. I admit this is stretching the terminology for “energy output in white dwarfs” but still …