***If anyone likes black holes he should move towards the center of our galaxy. Not only is there a supermassive black hole but also thousands of black holes that are remnants of ancient supernovae.***

https://www.jpl.nasa.gov/images/wise/20160915/PIA20027-16.jpg
*A glowing stream of material from a star as it is being devoured by a supermassive black hole.*
**Source: NASA/JPL-Caltech, Public Domain**

Scientists have long thought that the supermassive black hole at the center of our galaxy is surrounded by smaller black holes. But now astronomers have direct evidence that such black holes do exist and that there is many of them. This is great news and scientists can’t wait to start research on relations between them.

Sometimes it happens that a supermassive black hole attracts a smaller black hole to its vicinity and the smaller black hole pairs itself with a local star. This is how binary systems that fire flashes of x-rays during their birth are born. And it is these flashes that can be found by black hole hunters. The problem, as Chuck Hailey from the Columbia University says, is that the galactic center is very far away. From such a distance we can see only the strongest of flashes and they don’t get created often there, only once in a 100 – 1000 years.

That is why Hailey and his coworkers decided to focus on something else. Less bring but more consistent x-rays that are produced by the binary system after it has already been there for some time. The researchers used archived data from the Chandra observatory and looked for signs of such binary systems. They found 12 binary systems with a black hole that are less than 3 light years away from the supermassive black hole at the center of our galaxy. 

**Sources:**
* https://www.nature.com/articles/nature25029
* http://news.columbia.edu/content/New-Study-Suggests-Tens-of-Thousands-of-Black-Holes-Exist-in-Milky-Ways-Center