Shuang-Nan Zhang

Gamma-ray burst 230307A lit up the sky like a thunderclap: in seconds, it released more energy than the Sun will emit over billions of years. Three detectors—GECAM-B, GECAM-C, and Fermi/GBM—were looking in the right direction at that moment.

The black hole in the binary system Swift J1727.8-1613 flickers in X-rays like a campfire in the wind. But if you look closely at the rhythm of this flickering, you can see distinct 'humps'—bursts at specific frequencies, like drumbeats in the noise of a crowd.

In October 2022, the space-based detector GECAM-C caught the most powerful gamma-ray burst ever seen, GRB 221009A — an explosion that briefly became the brightest source of gamma rays in the sky. But the most interesting part came after: the instrument detected a series of additional flares, and one of them was record-breaking.

The Einstein Probe space telescope detected a celestial storm: after a short (0.4-second) gamma-ray burst — a cosmic lightning bolt — came a long roll of X-ray thunder. It lasted nearly 10 minutes. This is the first direct proof that such explosions leave a lingering X-ray afterglow.

The X-ray pulsar Centaurus X-3 is a neutron star that spins rapidly and emits pulses of X-ray light like a lighthouse. Scientists pointed three space telescopes at it and studied the polarization of its emission — how the electric field of the light wave oscillates.

A pebble dropped in a pond creates curved ripples, but from far away they appear as straight lines. Gamma-ray flashes from an evaporating black hole behave the same: a distant burst sends flat waves, while a nearby one arrives curved.

A massive star ends its life in a spectacular collapse: the core compresses into a neutron star or a black hole, while the outer layers fly off in a dazzling supernova.

An avalanche in a sandpile starts with a single grain. No one knows exactly where it will slip or how big the slide will be. But if you keep pouring sand, the pile itself reaches a state where avalanches of all sizes, from tiny trickles to massive collapses, follow the same law.