Astronomers solve 50-year mystery of a naked-eye star’s extreme X-rays

A star you can see with the naked eye has kept astronomers guessing for decades with its unusually powerful X-rays. Now, thanks to highly precise observations from Japan’s XRISM space telescope, scientists have finally uncovered the source: a hidden white dwarf companion pulling in material and generating extreme heat. This discovery not only solves a 50-year-old mystery surrounding Gamma Cassiopeiae, but also confirms the existence of a long-predicted type of binary star system.