Megumi Shidatsu

About 25,000 light-years from Earth, in the constellation Sagittarius, a dense veil wraps around the neutron star GX 13+1. It scatters X-ray photons the way fog scatters streetlight, and for a long time it hid the source's true power from astronomers.

The binary system SS 433 ejects two thin jets of gas at nearly the speed of light. One flies toward us, the other away from us. In April 2024 and March 2025, three instruments watched them simultaneously: the X-ray telescope XRISM, ordinary optical telescopes, and a near-infrared camera.

The Perseus galaxy cluster is a giant metropolis of thousands of star islands, bathed in an invisible ocean of scorching gas. Like urban smog, this gas preserves traces of all the chemical factories that have operated in galaxies for billions of years: supernova explosions that scatter freshly forged atoms across the surroundings.