Marianne Vestergaard

At the heart of galaxy NGC 4051 lies a black hole with a mass of 800,000 Suns. Around it swirls a blazing hot gas that shines brightly. This light doesn't reach us all at once: blue rays arrive first, then green, then red.

Galaxy Mrk 590 behaves like a radio receiver that sometimes picks up a signal and sometimes fades into static. Its supermassive black hole has been brightening and dimming for decades, and astronomers caught every such 'switch-on.' In 2017, the receiver came alive again, but the VLA radio telescope heard not the signal they expected.