C. Maitra

The ASKAP radio telescope in Australia has spotted a very faint glowing ring in the southern sky, like a soap bubble the size of several full moons. Inside the ring, exactly at the center, shines a tiny point. Usually, such a picture means one thing: a star exploded here, leaving behind an expanding shell and a collapsed core at its heart. But this pair has a quirk.

A massive star doesn’t simply fade away — it blows up as a supernova, leaving behind an expanding remnant and a wildly spinning neutron star — a pulsar. In this cosmic storm, astonishing patterns emerge, and the 'Nimbus'–'Thunder' system is a dazzling illustration.

The night forest is full of fireflies, but before, we only saw those that happened to be in the beam of a flashlight. That was the case with ultraluminous X-ray sources: points in other galaxies that shine in X-rays more brightly than a stellar-mass black hole can steadily emit. Telescopes looked at galaxies chosen for other purposes, missing most of the fireflies.