Classical novae: the thermonuclear runaway model.

The governing nuclear physics of a classical nova system are reviewed, in addition to an elaboration of the CNO cycle of the nuclear reaction sequence. Nova are known to be associated with binaries, with the late-type stars filling the Roche lobe and losing matter through the Lagrangian point, and accretion eventually occurring on the companion white dwarf. The rise to bolometric maximum is followed by a rise to a visual maximum, a constant bolometric phase, and then a turn-off phase, with an accompanying decrease in the intensity of the underlying radiation field. Distinguishing features of fast and slow novae are outlined, along with the rapid processes of the super-Eddington phase, which witnesses a transfer of significant mass to a large radius. Once the super-Eddington cycle begins, the CNO reactions govern the runaway, and features of the last three minutes, the constant luminosity phase, shell burning evolution, and winds and continuous ejection are detailed.