"Betelgeuse may have competition for the most exciting star about to go nova near Earth," writes Space.com. "Astronomers have discovered the secret of a strange star system that has baffled them for years, finding it contains a dead star about to erupt after overfeeding on a stellar companion." The supernova explosion of this cosmic cannibal could be as bright as the moon, making it visible with the naked eye over Earth even in broad daylight. The system in question is the double star V Sagittae located around 10,000 light-years from Earth, containing a white dwarf stellar remnant and its victim companion star, which orbit each other roughly twice every Earth day. The new research and the revelation of this white dwarf's imminent catastrophic fate answer questions about V Sagittae that have lingered for 123 years... White dwarfs represent the final stage of stars with masses around that of the sun, occurring when they run out of fuel for nuclear fusion... [W]hite dwarfs that have a stellar companion can get a second lease on life and a more conclusive and explosive end... [T]he stolen stellar material piles up on the surface of the white dwarf until it pushes this stellar remnant past the so-called Chandrasekhar limit of 1.4 solar masses. This is the mass limit that a stellar remnant has to exceed to trigger a supernova... However, this team found something very different and extraordinary happening with the stellar material being stolen by the white dwarf in V Sagittae... This investigation revealed that there is a giant halo of gas comprised of material stolen from the companion star wrapped around both the cannibal white dwarf and its stellar victim... "The white dwarf cannot consume all the mass being transferred from its hot star twin, so it creates this bright cosmic ring," team member Pasi Hakala from the University of Turku said. "The speed at which this doomed stellar system is lurching wildly, likely due to the extreme brightness, is a frantic sign of its imminent, violent end." "The matter accumulating on the white dwarf is likely to produce a nova outburst in the coming years, during which V Sagittae would become visible with the naked eye," Pablo Rodríguez-Gil from Spain's Instituto de Astrofisica de Canarias said. "But when the two stars finally smash into each other and explode, this would be a supernova explosion so bright it'll be visible from Earth even in the daytime." The research was conducted with the Very Large Telescope (four individual telescopes high in the mountains of Chile) — and published last week in the journal Monthly Notices of the Royal Astronomical Society.Read more of this story at Slashdot.