3 billion light years away, two huge black holes succumbed to one another’s gravitational pulls, collided…and merged, resulting in the creation of a new, single black hole.
The discovery of this interstellar occurrence proves that gravitational wave astronomy is here to stay. LIGO (the Laser Interferometer Gravitational-wave Observatory) used this special type of astronomy to make this discovery. Astronomers normally observe the universe in light wavelengths. However, black holes, as far as we know, do not emit light. In fact, they absorb it (that’s right, not even light can escape a black hole). This makes observing black holes extremely difficult.
However, the new astronomy of gravitational waves is allowing us to study the mysterious entities known as black holes. “We’re entering a whole new kind of astronomy,” said Clifford Johnson, a USC theoretical physicist. “Every time we find a new way of looking in the sky, we understand our universe in a whole new way, at a whole new level.”
That is very exciting news indeed, as there is so much of our universe that we do not yet understand.
Not only that, but the success of this new astronomy also confirms Albert Einstein’s 1915 theory of relativity. LIGO’s detectors give scientists a whole new way to observe black holes.
This latest find marks the third time that LIGO has detected a black hole collision. What makes this find different, however, is the distance from our planet. The first two black hole collisions happened around 1.3 million and 1.4 million light years away, respectively. This collision occurred around 3 billion light years away from us. What this basically means is that, 3 billion years ago, these two black holes collided, and we are just now hearing it in 2017.
The two black holes had solar masses of 31.2 and 19.4, colliding to create a singular black hole with a 48.7 solar mass, the remaining two suns of mass being morphed into gravitational waves. The solar mass of this merger is an intermediate weight class that scientists were not expecting to see. Most black holes are formed when the center of a dying star collapses in on itself, and these are usually a few times the mass of the sun that spawned them, much smaller than this new singular black hole. Others are classified as “supermassive black holes”, which have solar masses of billions and usually lie at the center of a galaxy. This singular black hole is in an intermediate weight class, bigger than the usual sun-spawned black holes, but way too small to be classified as supermassive.
“We have further confirmation of the existence of stellar-mass black holes that are larger than 20 solar masses—these are objects we didn’t know existed before LIGO detected them,” said MIT’s David Shoemaker, spokesperson for the LIGO Scientific Collaboration.
LIGO Laboratory executive director David Reitze stated that LIGO is “establishing itself as a powerful observatory for revealing the dark side of the universe”.
LIGO, meanwhile, is hoping to continue observing some of the most bizarre and elusive occurrences in the universe. Next on their agenda, among other things, is observing the collision of neutron stars.