Ackermann, M.M.AckermannAjello, M.M.AjelloAlbert, A.A.AlbertCavazzuti, ElisabettaElisabettaCavazzutiCiprini, StefanoStefanoCipriniGasparrini, DarioDarioGasparrini2020-09-172020-09-172014-08-01https://hdl.handle.net/20.500.13025/3867Science, Volume 345, Issue 6196, pp. 554-558 (2014).A classical nova results from runaway thermonuclear explosions on the surface of a white dwarf that accretes matter from a low-mass main-sequence stellar companion. In 2012 and 2013, three novae were detected in gamma rays and stood in contrast to the first gamma-ray-detected nova V407 Cygni 2010, which belongs to a rare class of symbiotic binary systems. Despite likely differences in the compositions and masses of their white dwarf progenitors, the three classical novae are similarly characterized as soft-spectrum transient gamma-ray sources detected over 2- to 3-week durations. The gamma-ray detections point to unexpected high-energy particle acceleration processes linked to the mass ejection from thermonuclear explosions in an unanticipated class of Galactic gamma-ray sources.10.1126/science.1253947http://adsabs.harvard.edu/abs/2014Sci...345..554A2014Sci...345..554A