One of the final forms stars can take is a white dwarf. These are objects roughly the mass of the Sun that are compressed down to something more like the size of the Moon, and at this density, they have a powerful surface gravity. If you tried to stand on one, you would be compressed to a film of atoms on the star’s surface.

Don’t stand on stars, people. Just don’t do it.

In addition to being a creative way to compact people while killing them with gravity, white dwarfs also seem to make a hobby of letting off thermonuclear blasts with physics that’s not all that different from nuclear weapons. Nuclear bombs work, very roughly, by using shaped charges to compress fissionable material until a thermonuclear explosion occurs. The stuff in nuclear bombs is relatively safe as long as it doesn’t get scrunched together. Well, the gravity on the surface of white dwarfs can do the same thing with a little help and from magnetism. These white dwarfs are stealing hydrogen fuel from their neighbor stars, funneling it along their magnetic fields to their polls, and there it explodes once it hits a critical mass.

The TESS telescope has now seen four different events where several hour-long blasts have occurred. This work is published in Nature and led by Simone Scaringi.

More Information

Durham University press release

ESO press release

“Localized thermonuclear bursts from accreting magnetic white dwarfs,” S. Scaringi et al., 2022 April 20, Nature

“Triggering micronovae through magnetically confined accretion flows in accreting white dwarfs,” S. Scaringi et al., to be published in Monthly Notices of the Royal Astronomical Society (preprint on arxiv.org)