Binary orbits as the driver of gamma-ray emission and mass ejection in classical novae

Understand

Classical novae are the most common astrophysical thermonuclear explosions, occurring on the surfaces of white dwarf stars accreting gas from companions in binary star systems.

• Novae typically expel ~10^(-4) solar masses of material at velocities exceeding 1,000 kilometres per second.
• However, the mechanism of mass ejection in novae is poorly understood, and could be dominated by the impulsive flash of thermonuclear energy, prolonged optically thick winds, or binary interaction with the nova envelope.
• Classical novae are now routinely detected in gigaelectronvolt gamma-ray wavelengths, suggesting that relativistic particles are accelerated by strong shocks in the ejecta.