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Experimenters in Germany have glimpsed the kind of strange, non-atomic matter thought to fill the cores of merging neutron stars.
Brief cosmic blips called fast radio bursts have puzzled astronomers since their discovery earlier this decade. Now researchers appear to be close to understanding what powers them.
New observations of extreme astrophysical systems have “brutally and pitilessly murdered” attempts to replace Einstein’s general theory of relativity.
A mysterious object that repeatedly bursts with ultra-powerful radio waves must live in an extreme environment — something like the one around a supermassive black hole.
A number of high-energy anomalies raised hopes that astrophysicists had seen their first direct glimpses of dark matter. New studies suggest a different source may be responsible.
The core of a neutron star is such an extreme environment that physicists can’t agree on what happens inside. But a new space-based experiment — and a few more colliding neutron stars — should reveal whether neutrons themselves break down.
Newly discovered “standard sirens” provide an independent, clean way to measure how fast the universe is expanding.