Astronomers have uncovered dramatic behaviour in the binary star system V Sagittae: a white dwarf is siphoning material from its larger companion at a rate never before seen. The two stars orbit each other every 12.3 hours, flirting ever closer in what researchers describe as a deadly dance.

The intense material transfer causes the system to burn with extraordinary brightness which has puzzled scientists since V Sagittae’s discovery in 1902. Observations via the Very Large Telescope in Chile revealed a ring of gas encircling both stars formed from matter the white dwarf cannot immediately consume. 

Researchers predict that as matter builds up on the white dwarf’s surface, a nova outburst will occur, making V Sagittae visible to the naked eye. Eventually, when both stars collide or the white dwarf exceeds stability limits, the system may explode as a supernova so bright it could even be seen during daytime from Earth.

This new study, published in Monthly Notices of the Royal Astronomical Society, not only explains V Sagittae’s century-old mystery of erratic brightness, but also offers insight into how binary stars behave in their final, explosive phases.