A black hole has been discovered right in our cosmic back yard – but little did we know that the world nearly knew about this amazing find so close to us nearly two decades ago were it not for a freak accident.
A thousand light years from Earth lurks a massive hidden object at least four times as heavy as the Sun.
But if any light were able to escape the object’s intense gravitational pull, you’d be able to see it with the naked eye.
Astronomers were able to detect it because it’s part of an orbital group of objects, called HR 6819, that includes two stars.
The stars are orbiting what looks like an empty void in space.
But at the centre of that void lurks a black hole.
Black holes are among the most exotic objects in the universe. The super-dense remnants of collapsed stars, their gravitational fields are so powerful that not even light can escape them.
While the black hole hidden at the centre of HR 6819 has only just been discovered, it could have been revealed many years ago.
Thomas Rivinius, an astronomer at the European Southern Observatory in Santiago, Chile, was part of a team of astronomers that noticed the strange behaviour of the two visible stars in the constellation Telescopium in 2004.
“We thought it was only two stars,” he told Eos.org. But he said “one of them was being flung around” – a tell-tale sign of a hidden gravitational force at work.
Tragically, before the team could publish their results, one of the astronomers died in a car accident and the entire project was put on the back-burner until the publication of a similar observation this year reminded Rivinius of the discovery.
Marianne Heida leads a team at the European Southern Observatory’s site in Germany.
She says they discovered the massive object by accident, but that there are probably many more out there to be spotted – some even closer.
“There must be a bunch of them closer but that we haven’t found yet, but this is the closest that we know,” she told New Scientist.
“Based on the number of stars in the Milky Way, we expect that there are about 100 million of these small black holes, and we’ve only found less than 100 of them.”
Working on the basis that black holes are distributed evenly throughout the galaxy, there should be at least one within 30 to 40 light years from the Earth – although that means the nearest black hole could be some two hundred and six trillion miles away, so you shouldn’t worry about falling into one any time soon.
Physicist Jakub Scholtz has theorised that the mysterious Planet X, an undiscovered body at the edge of the solar system responsible for some peculiarities in the orbits of the outer planet, could be a small black hole.
That could explain why the elusive object remained undiscovered. A black hole with five times the mass of Earth would be about the size of a grapefruit. One with 10 Earth masses would still be no bigger than a bowling ball.
But, if one were lurking at the edge of the Solar System, it would tug on objects in the outer solar system just like a planet.
Telescopium is visible from anywhere south of the 33rd parallel – coincidentally a line on the map associated with all sorts of mystical lore and the location of both Kennedy assassinations as well as the sighting of the Phoenix Lights, an as-yet unexplained UFO sighting in 1997 .
The constellation is visible right across Southern California, Alabama and Texas.
The only place in Europe where you can spot HR 6819, though, is a tiny Portuguese-owned island just north of Madeira.