A Nova Outburst Powered by Shocks
Fig 1. A white dwarf and it's companion star. The purple color shows the gamma-ray emissions produced by shock wave. （produced by NASA）
Fig 2. Fermi observations of ASASSN-16ma. (produced by Kwan-Lok Li)
Fig 3. The Gamma-ray and optical light curves show a remarkable correlation, implying that the majority of the optical light comes from reprocessed emission from shocks rather than the white dwarf. (produced by Kwan-Lok Li)
NASA news: https://asd.gsfc.nasa.gov/blueshift/index.php/2017/09/05/shock-waves-power-an-exploding-star/
Nature astronomy letter: https://www.nature.com/articles/s41550-017-0222-1