Nucleosynthesis in nova explosions: Prospects for its observation with focusing telescopes

Abstract

Nova explosions are caused by the explosive burning of hydrogen in the envelope of accreting white dwarfs. During the thermonuclear runaway some radioactive isotopes are synthesized, which emit γ -rays when they decay. The γ -ray signatures of a nova explosion still remain undetected, because even the best instruments like SPI onboard INTEGRAL are not sensitive enough for the dim and broad lines emitted by novae at their typical distances. A very different situation is expected with a focusing telescope, like MAX. Prospects for detectability with a future γ -ray lens telescope are presented, with a special emphasis on the important information that γ -rays would provide about the explosion mechanism and the underlying white dwarf star.