This artist's conception shows the biggest stellar-mass black hole (upper left), which weighs 24 to 33 times as much as the Sun. It is pulling gas from a companion Wolf-Rayet star (lower right). Experts say the black hole was "born fat, it didn't grow fat." Credit: Aurore Simonnet/Sonoma State University/NASA
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This close-up from the artist's conception shows gas spiraling into the heftiest known solar-mass black hole. The gas heats up and emits X-rays, which allows astronomers to deduce the black hole's presence. Credit: Aurore Simonnet/Sonoma State University/NASA
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