November 27, 2013 - Discover
Imagine camping in the woods, when you hear what sounds like a chainsaw, but then see that the ruckus is coming from a tiny bird. The experience changes the way you think about little birds, right? And that’s exactly what’s happened to astronomers, who detected what sounded like a black hole behemoth and found, instead, a black hole baby.
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The researchers who published the astronomy-upending paper used the Gemini telescope to study the light coming from this system, named M101 ULX-1. It’s 20 million light-years away in the spiral galaxy M101 (often called the Pinwheel galaxy). Made up of the black hole and a companion star, the system turned out to be relatively free of hydrogen, suggesting the star was of a particular variety known as a Wolf-Rayet. Knowing what kind of star the companion was, the researchers could determine from its light that it was about 19 times as massive as the sun (typical for these rare stars).
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