Classical novae as lithium factories in the Galaxy

International audienceThe abundance of lithium observed in very young stellar populations is ~ 4 times larger than the primordial one estimated by recent Planck measurements. Since Lithium is easily destroyed in stellar interiors, the search for astrophysical sources responsible for of the observed lithium over-abundance was a mystery for decades. In this talk I will present the results of an on-going survey dedicated to the study of nova outburst with high-resolution spectrographs at ESO/VLT. In particular, I will concentrate on the recent detection of beryllium-7 in the spectra of recent classical novae. While this finding is a further confirmation of the occurrence of the thermo-nuclear runaway in nova explosions, at same time it implies that classical novae are the main factories of lithium in the Galaxy