Gamma-ray emission from classical novae

The main mechanisms through which classical novae can emit gamma-rays are reviewed. Gamma-ray emission has its origin on the disintegration of some short- and medium-lived radioactive nuclei, like (13)N, (18)F, (7)Be and (22)Na. As a result of the disintegration of these nuclei, the emission has two components: lines (511, 478 and 1275 keV) and continuum (between 20-30 keV and 511 keV). The detection of gamma-rays from novae would provide important diagnostics of the explosion mechanism and, specially, a direct insight of the nucleosynthesis processes: the (7)Be and (22)Na lines at 478 and 1275 keV directly reflect the amount of these nuclei in the ejecta, whereas the 511 keV line and the continuum reflect both the amount of (18)F and (13)N and the dynamical properties of the expanding nova envelope. The unsuccessful, to date, attempts to detect gamma-rays from novae are also reviewed, together with the prospects for future detectability.