Tue July 31, 2012
Telescope Targets Black Holes' Binges And Burps
Originally published on Tue July 31, 2012 6:45 am
NASA's newest space telescope will start searching the universe for black holes on Wednesday. Scientists hope the NuSTAR X-ray telescope, which launched about six weeks ago and is now flying about 350 miles above the Earth, will help shed some light on the mysteries of these space oddities.
Mission control for the telescope is a small room on the University of California, Berkeley, campus, where about a dozen people with headsets rarely look up from their screens.
Fiona Harrison, a professor of physics and astronomy at the California Institute of Technology, is the principal scientist for the mission. If there's one word that describes her past few weeks, it's "nail-biting," she says.
The beginning of a space telescope's life is particularly stressful. It has to be switched on remotely, including the unfurling of a 33-foot arm that will act like a giant telephoto lens.
Now, the $170 million telescope is just about ready to begin its hunt for black holes.
"We're not actually seeing the black hole," Harrison says. "What you're actually seeing is the stuff that's attracted to it."
Harrison says they're called black holes because not even light can escape their gravity. But black holes aren't passive — they pull in tons of dust and gas. The material swirls around faster and faster, just like a bathtub drain, and gets hotter.
"The material is so hot that it radiates high-energy X-rays," she says, just like the ones doctors use. She says researchers observed them before, but it's like reading a book without your glasses.
"We know there's a story there, we know there's text, but we haven't been able to read the letters," she says.
With NuSTAR, they'll be able to see these X-rays at a higher resolution than ever before.
"It's incredibly exciting because we don't actually know what the text is going to say. And now we're going to be able to read it clearly for the first time," she says.
Harrison hopes the telescope will unlock some of the mysteries around black holes — like how they grow.
Eliot Quataert, an astronomy professor at UC Berkeley who is not on the mission staff, says black holes grow just like we do — by eating.
"They eat dramatically, but rarely," he says.
And at the very center of our galaxy, there's a super massive black hole that has eaten quite a bit. But we're still here.
"The misconception that's out there is that black holes are a vacuum cleaner that will inevitably suck in everything around them," Quataert says. For the most part, black holes are on a forced diet — they've already eaten everything close by.
"But then every once in a while, there will be a lot of gas that gets funneled to the center of a galaxy, and the black hole will grow in a big spurt," he says.
Quataert says seeing this black hole mealtime with the telescope could reveal more about the extreme physics behind it. That could answer questions about how galaxies form. UC Berkeley astronomer Joshua Bloom hopes NuSTAR will find another strange phenomenon: black hole burps.
"You can think about this black hole burping as if you're on a feeding frenzy and you can't fit that many hot dogs in your mouth," Bloom says.
Early last year, Bloom and other astronomers noticed a black hole devouring a star. The black hole spit out a huge jet of material — a burp. That might sound weird, since nothing can escape a black hole, right?
"These are sort of the Las Vegas of the universe. What happens in a black hole stays inside of a black hole. But on the outskirts of them, that is where there's tremendous action," he says.
Bloom says they're hoping to see more of these rare events and others that are still unknown to astronomers. The NuSTAR space telescope's mission is expected to last at least two years.