Stellar Lighthouse: A White Dwarf Pulsing with Radio Waves ✦
Astronomers have long scratched their heads over mysterious radio bursts that repeat every few minutes to hours. It turns out one of these “cosmic lighthouses” is a white dwarf stealing matter from a companion star. Could other enigmatic signals be born in similar binary systems?
In space, an astonishing pair has been found: a tiny but monstrously dense white dwarf and its puffy, lightweight neighbor — a red dwarf. They race around their common center every 1.37 hours. The white dwarf's gravity rips gas from its companion — mostly hydrogen and helium — and that gas, spiraling inward, slams into the magnetic poles, heating up to millions of degrees. Each time the pole faces our way, a radio flash erupts — just like a lighthouse beam piercing the darkness.
This mechanism resembles pulsars — rapidly spinning neutron stars, discovered by Jocelyn Bell Burnell in 1967 — but here the period is much longer. And the key discovery: the white dwarf's mass is teetering on the Chandrasekhar limit. Add just a pinch more matter, and the star will collapse, igniting a supernova that outshines an entire galaxy. Right now, this lighthouse is operating on the brink of its own destruction.
🎯 The radio signal showed patterns resembling ripples from two stones thrown into a pond — something previously seen only with Jupiter and its moon Io.