Even though the gravity from black holes is so strong that light can’t even escape, we can see the radiation from the superheated matter that’s about to be consumed. Until now, scientists haven’t been able to explain how all this matter continuously falls into the black hole – it should just orbit, like planets going […]
The supermassive black holes that lurk at the heart of most galaxies have enormous appetites. They’ve already consumed millions of times the mass of our own Sun, and they’re not done yet. Everything’s on the menu: mostly gas, dust, planets and stars, but the occasional exotic delicacy gets consumed too. “Compact objects”, such as stellar […]
Black holes… you know. Cosmic singularities that can contain the mass of billions of stars like our Sun. Where the pull of gravity is so strong, nothing, not even light can escape their fearsome grasp. They’re the source of much discussion, indirect observation and science fiction speculation. But according to George Chapline from Lawrence Livermore […]
Astronomers have been puzzling over a mystery for a few years now, and they think they might have an answer. Everywhere you look, there’s a diffuse glow of background X-ray radiation – but where’s it coming from? Astronomers pointed the Chandra X-Ray Observatory at a patch of sky for a total of 23 days over a 2-year period, and resolved 600 separate point sources. This isn’t a background glow at all, but the X-ray radiation from hundreds of millions of supermassive black holes, like the one at the heart of the Milky Way.
An international team of astronomers have analyzed a recent short gamma-ray burst, and they think it’s the last scream of a neutron star being gobbled up by a black hole. The burst was discovered on July 24, 2005 by NASA’s Swift satellite, and then astronomers performed followup observations with a variety of instruments. The length of the explosion and the wavelengths of radiation emitted have led astronomers to the conclusion that it had to be a neutron star colliding with a black hole.
Astronomers were expecting that a massive star in the Westerlund 1 star cluster should have collapsed into a black hole. Instead, it became a neutron star. Since this star was 40 times the mass of the Sun before it collapsed, it should have been a prime black hole candidate. So why did it end up as a neutron star? It’s possible that the star blew off most of its mass at the end of its life, so there just wasn’t enough material to form a black hole.
The Hubble Space Telescope has discovered a supermassive black hole without a surrounding galaxy. These black holes and their galaxies are usually linked, so it’s an unusual discovery. One possibility is that the host galaxy was stripped away during a collision with another galaxy. Another possibility is that the black hole is surrounded by a large amount of material, it’s just dark matter, so Hubble couldn’t detect it.
Monday’s gamma ray burst might have been just what astronomers have been hoping to see for decades – the birth of a new black hole. GRB 050509B was a short gamma ray burst, lasting only 50 milliseconds, which means it could be the result of a collision between two neutron stars, or even two black holes. NASA’s Swift observatory detected the explosion, tracked its location, and focused its large telescope within a minute of its occurrence.
Here’s a relief. Instead of being painfully stretched (aka spaghettified) by the immense tidal forces around a black hole, you’d probably just be roasted by the intense heat. Professor Andrew Hamilton at the University of Colorado predicts that only the smallest black holes would actually stretch you out like this. All the larger, supermassive black holes are already choking on enough material, that their surrounding environment is a superhot plasma heated to millions of degrees and blasting out intense radiation.
Just before matter is gobbled up by a hungry black hole, it’s hurtling around the monster at nearly the speed of light. This heats up the material and it can release a tremendous amount of energy as X-rays. Different elements release energy with a specific fingerprint that astronomers can detect. Researchers from Europe have measured iron as it hurtles around black holes and found a relativistic effect because it’s moving so quickly. The team averaged out the X-ray light from 100 distant black holes to show the telltale signature of material about to be consumed by a black hole.