A cosmic mystery: why a recently-discovered black hole is puzzling astronomers
Since the phrase 'black hole' was popularized back in 1969, scientists have developed complex theories to help make sense of the way they grow and form. But new research published this week in the journal Nature could be calling some of those theories into question. The astronomers say they've discovered a black hole that's so young - yet so huge - that it's making them rethink their understanding of black holes and of the universe. So what makes it so special? Here are four things to consider, according to Scott Young, astronomer at the Manitoba Museum's Planetarium.
1. It's a baby, in cosmic terms
Scott Young says it's a bit of a mystery how a black hole that came into being only 900 million years after the big bang could be so huge.
"It's kind of like children. If you looked at a 9-month-old child and they were six foot foot and 240 pounds, you'd kind of wonder what they'd been eating. And it's the same kind of thing here. Nine hundred million years is not really long enough for a black hole to sort of grow big and strong like this one has done," explains Young.
2. It's a heavyweight with the same mass as 12 billion suns
"Black holes, when they are formed from the single star, can grow by devouring other things that are nearby them like other stars, dust or gas. If there is lots of stuff for them to eat then they can grow very large," says Young.
The puzzling part, Young says, is that this particular black hole grew in mass so quickly in spite of its relatively young age.
"What that means is that the material that is inside the black hole that's exerting all this gravity is exerting all of that force equivalent to 12 billion of our suns. It's a huge amount of material that has been packed down into this tiny little space that just makes the gravity extremely powerful. But most black holes can't get this big, so this is right on the upper limit of the size of black holes that we've seen," says Young.
3. This black hole was discovered in the middle of one of the brightest quasars ever known and is 420 trillion times brighter than the sun
Young says quasars are the most distant objects that can be seen from earth, using the biggest telescopes. And they're located right near the edge of the universe.
"We don't know exactly what they are because all we can see is this little speck of light. So discovering this massive black hole in the centre of one might give us some insights into what quasars are doing and exactly and how they form," says Young.
4. This black hole discovery challenges theories about the very beginnings of the universe
"Theories of how the whole universe came together can't really account very well for a black hole growing this big, this quickly," says Young.
He says this discovery suggests that theories about the early universe and about the conditions after the Big Bang are not yet fully refined. But he says the size and age of this black hole may not be perfectly accurate.
"The difficulty is that these objects are so far away that there's some inherent errors in our measurement. You can't get things perfectly precise, when you're looking at all the way to the edge of the universe. So we just have to make sure that other observers get a chance to take a look at this thing and come up with similar numbers before we throw out too many theories," says Young.