New studies of nuclear decay γ-rays from novae

The cause of the nova outburst is a thermonuclear runaway (TNR) in hydrogen rich material transferred by a companion onto a white dwarf. Studies of this phenomenon have shown that the TNR produces large concentrations of the short lived positron unstable isotopes of the CNO nuclei which are transported to the surface by convection so that early in the outburst we expect significant numbers of radioactive decays to occur at the surface. The resulting γ-ray emission may be detectable from nearby novae early in their outbursts. The TNR is also expected to produce substantial amounts of 7Be and 22Na. Their decays also yield potentially detectable levels of γ-ray emission for relatively nearby novae. We are also interested in the role played by novae in the production of the ∼2M· of 26Al found in the galaxy. In order to improve our predictions of this phenomenon, we have performed a new set of calculations of TNR's on ONeMg and CO white dwarfs with an updated nuclear reaction network and opacities