Mystery of Cassiopeia star solved after 50 years ⚡ экспресс
For fifty years, the strange X-ray light from γ Cassiopeiae was a mystery. The XRISM telescope noticed that its frequency changes over time, like the siren of a passing car. It turns out that an invisible white dwarf orbits the star, pulling in matter and heating it up until it glows. This cosmic dance reveals the secrets of how massive binary systems evolve.
For fifty years, astronomers couldn't understand the powerful X-rays from the star Gamma Cassiopeiae. They suspected an invisible companion, but had no proof. Japan's XRISM telescope, armed with high-resolution spectroscopy, caught tiny shifts in the emission lines. Those oscillations precisely matched the motion not of the main star, but of its tiny partner.
It turned out to be a white dwarf – a superdense stellar leftover whose maximum mass was worked out by Chandrasekhar. Gas from the big star streams toward the dwarf and, like water down a drain, spirals into a searing hot disk. There it heats to millions of degrees, giving off that very X-ray glow. The find is like solving a magic trick: we finally see where the matter disappears.
Such pairings, it turns out, aren't rare: one in ten massive stars with a disk conceals a white dwarf. This helps us grasp how supernovae and neutron stars are born. The cosmos is teeming with invisible drains, gobbling up their neighbors.
🎯 A white dwarf is so dense that a sugar-cube-sized chunk of it would outweigh a truck.