A group of researchers from National Astronomical Observatory of Japan (NAOJ), discovered a black hole that is disturbing, because its size is similar to the planet Jupiter and is around our galaxy.
In an article published in arXiv, It is mentioned that Shunya Takekawa and his team managed to detect a series of undulations in a cloud of interstellar gas, suggesting the presence of a black hole of intermediate mass running through our galaxy.
Most of the black holes known belong to three categories, according to their dimensions. The smallest ones, barely a few miles in diameter, are formed after the gravitational collapse of a star and are usually identified thanks to the fact that many of them are part of double star systems. We see them thanks to the effects they produce on their companion stars, to which they often "steal" large amounts of matter.
The largest, with masses equivalent to those of millions and even billions of suns, reside in the center of most galaxies. They are supermassive black holes, those that with their tremendous gravity are able to hold together and turn around the hundreds of billions of stars that make up the galaxies.
Finally there are those of intermediate size, like the one that Japanese astronomers have just found. Its dimensions are those of a planet (one of the largest in this case) or even those of a star. They are much more rare to see than those of the other two categories, and the reason is that they roam alone through space.
The few intermediate sized black holes known to roam very close to the galactic centers. We can only see them on the rare occasions when they encounter some kind of material (a gas cloud or an unfortunate star) and begin to devour it.
According to Takekawa, these black holes move relatively fast compared to the gas that surrounds them, so they only absorb a small part of it and, therefore, produce very little light.
For the researcher, this particular black hole will probably take about 10,000 years to consume all the gas that served to reveal its position.