Astronomers discover a white dwarf star firing a cosmic shockwave across the Milky Way

A rare and striking cosmic phenomenon has been spotted in the Milky Way. Astronomers using the Very Large Telescope have observed a white dwarf star generating a glowing shockwave as it races through space. The discovery, located about 730 light-years from Earth, reveals a dramatic interaction between two stars in the constellation Auriga.

The white dwarf is part of a binary system, locked in a tight orbit with a red dwarf companion. The smaller red dwarf, roughly a tenth of the sun's mass, circles the white dwarf every 80 minutes. Despite its compact size—slightly larger than Earth—the white dwarf packs a mass comparable to the sun.

The white dwarf's powerful magnetic field is stripping gas from its companion. This stolen material fuels intense energy and radiation, creating a vivid bow shock as the system moves through interstellar space. The shockwave glows in vivid colours, caused by gas being heated and excited by the collision.

Observations suggest this process has been active for at least 1,000 years. No other white dwarf stars have been seen producing similar shockwaves, making this the first known system of its kind in the Milky Way.

The discovery provides a unique opportunity to study extreme stellar interactions. The shockwave's structure and longevity offer clues about the system's evolution over centuries. Researchers will continue monitoring the binary to better understand its behaviour and energy release.