What Is a ‘Stealth Black Hole,’ and Should We Worry One Will Gobble Us Up?


Image: X-ray: NASA/CXC/Univ. of Alberta/B.Tetarenko et al; Optical: NASA/STScI; Radio: NSF/NRAO/VLA/Curtin Univ./J. Miller-Jones
This week, scientists announced they’d found what’s been called a “stealth black hole” lurking in Milky Way, which seems to be slowly munching away at its companion star. Their research suggests our galaxy could be peppered with black holes we didn’t know about before, like a galactic piece of Swiss cheese.

By Elizabeth Howell | MOTHERBOARD

So, what is a “stealth black hole” anyway?

It’s a black hole that seems to give off radio waves. This one didn’t have the telltale X-ray radiation that black holes usually give off when they suck in material from nearby stars, forming a disc that glows brightly. That’s because it eats its companion star’s material very slowly, gently grazing on it instead of fully chowing down, for reasons that are poorly understood. Where there’s one slow eater, there likely are many others.

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