What's a Micronova?

Micronovae are thermonuclear explosions occurring in localised footprints at the magnetic poles of accreting white dwarfs. Discovered through optical timing data from NASA's TESS mission, these rapid bursts are about one-millionth of the energy of classical novae.

We believe the white dwarf's magnetic field acts as a funnel, confining fresh material onto the stellar poles (somewhat analogous to the aurorae). This magnetic bottleneck allows critical ignition pressure and temperature to build up in a much shorter time, requiring far less material than a global classical nova.

Because these bursts fade in just several hours, they are incredibly elusive. Catching them in action explains why they went undetected for decades.