After 20 years, scientists finally explain the Crab Pulsar’s strange “zebra stripes” - Science Daily

5 min readFrancis ReddySep 18, 2026 Article Using data from the Japan-led XRISM (X-ray Imaging and Spectroscopy Mission) observatory, astronomers have directly observed a giant star’s outflow, called a stellar wind, being captured by its compact companion and providing the power source for strong X-ray flares. The research is part of NASA’s exploration of the extreme universe to better understand how the cosmos works. “We’ve never before seen clear indications of wind plasma falling onto a compact object,” said Roi Rahin, a researcher at UMBC (University of Maryland, Baltimore County) and NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We can now test our understanding of these processes in much greater detail.” A paper describing the findings published Friday in the journal Science Advances. The target system is BP Crucis, a high-mass X-ray binary located about 13,000 light-years away in the southern constellation Crux. The primary star, known as Wray 977, is a blue hypergiant about 40 times the Sun’s mass and 60 times its size. It’s so big, hot, and luminous that ionized gas constantly streams away from it, a phenomenon astronomers call a stellar wind.