NASA astronaut Jonny Kim and Roscosmos cosmonauts Sergey Ryzhikov and Alexey Zubritsky landed on Russia's Soyuz MS-27 on Dec. 9, 2025, after 245 days on the International Space Station.
White dwarfs are called stellar remnants because they're what's left of main sequence stars after they've shed most of their mass and ceased fusion. But despite being mere remnants for whom fusion is only a distant memory, they can still be the locations of enormously powerful thermonuclear explosions called novae.

