Black holes are one of the biggest mysteries in the universe. We know that they are the last stage in a star’s life cycle and are formed when a star collapses under the weight of its own gravity. However finding black holes has been tricky. It has been just with the advent of radio telescopes that we have discovered that they can be located by the radioactive emission of matter that falls into them. This has helped us to be better able to find them. Answering the where is the nearest black hole is tricky as it is subject to change as technology for detecting black holes improves. At first scientist believed that the nearest black hole to Earth was the one at the center of the Milky Way Galaxy. This seemed to be debunked by the discovery of a new black hole only 1600 light years away.
This new black hole is actually a rare type of black hole called a micro quasar. This new black hole has been named V4641 Sgr since it located in the Sagittarius arm of the Milky Way. The reason it is visible is because of the star that orbits it. The gases of this star are steadily being absorbed by this black hole. These gases emit radiation that can be detected by Earth’s telescopes.
V4641 Sgr was first discovered as a black hole in 1999. Astronomers actually thought it was a star. However upon closer observation it was noticed that is brightness was six times greater than when first observed further observation through radio telescopes led astronomers to conclude that it had all the hallmarks of a black with an orbit star.
However the evidence proved that it is fifteen times further away than first anticipated. This just shows how in exact a science finding black holes still is. By their definition they are basically invisible so scientists looking for them have to rely on observations of matter. Theoretical models of the gravity of black holes give physicists and astronomers an idea of how matter would act near a black hole. Using these characteristics they try to find likely candidates. However the final proof is difficulty of detection. If the radiation produced cannot be traced back to its source then it is a strong candidate for being a black hole.
Try to find out where the nearest black hole is has important implications. It can help us know whether they Earth is in danger of passing near one. We wouldn’t have to be close to the side effects of its gravitational field. There is also the fact that learning more about where black holes are located can help us learn more about galaxy formation since most astrophysicists believe that the center of most galaxies have black holes.
If you’d like more info on Black Holes, check out NASA Science Page about Black Holes, and here’s more information from NASA from their educational pages.
We’ve also recorded an episode of Astronomy Cast all about black holes. Listen here, Episode 18: Black Holes Big and Small.