Explosive Death of Twin Stars Will Be Visible in Daytime

Astronomers say a star system 10,000 light-years away could put on one of the brightest shows in the night sky, with a supernova so intense it may be visible from Earth—even in daylight. The system, V Sagittae, is a duo: a white dwarf and a larger companion star locked in a tight orbit in the constellation Sagitta. Researchers say the white dwarf is siphoning material from its partner at an unprecedented rate, making the pair among the galaxy's brightest X-ray sources, Live Science reports. This cosmic feeding frenzy is expected to end in a dramatic collision, producing a supernova that could outshine everything else in the night sky.

Before the grand finale, astronomers anticipate a nova outburst—an explosion triggered when the white dwarf accumulates too much material, briefly making V Sagittae visible to the naked eye. Data from the European Southern Observatory's Very Large Telescope helped scientists examine the system's mass and behavior, though questions remain about the exact size of the stars. What is clear is that V Sagittae's brightness and erratic light patterns set it apart from similar systems. Estimates suggest the supernova, which will be as bright as the moon, could occur as early as 2067. The nova that will precede it could happen at any time.

"V Sagittae is no ordinary star system," says Phil Charles from Southampton University, co-author of a study published in the Monthly Notices of the Royal Astronomical Society. "It's the brightest of its kind and has baffled experts since it was discovered in 1902," he says, per the BBC. The study, he notes, "shows that this extreme brightness is down to the white dwarf sucking the life out of its companion star, using the accreted matter to turn it into a blazing inferno."

Researchers say a bright ring of gas is encircling both stars, a phenomenon that could change theories about the life and death of stars. "The white dwarf cannot consume all the mass being transferred from its hot star twin, so it creates this bright cosmic ring," says study co-author Pasi Hakala from the University of Turku, per ScienceDaily. "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."