Posts tagged black holes
Gravitational waves are the elusive ripples in spacetime that are theorized to pervade the entire Universe, generated by violent events, chronicling the evolution of some of the most massive objects in the Cosmos. Now, by using a clever technique to measure the observed variations in pulsar spin rates, astronomers may be getting close to not only observing the presence of these waves, but also understanding why some of the biggest black holes are so fat. Read more
Astronomers have conclusively measured the spin of a black hole for the first time by detecting the mind-bending relativistic effects that warp space-time at the very edge of its event horizon — the point of no return, beyond which even light cannot escape.
That, my friends, is pure-squeezed awesomejuice. Read more
"So, what do you do for a living?" "I just analyze data from radio telescopes… oh and I take pictures of black holes." Pretty awesome job.
A giant black hole is thought to lurk at the center of the Milky Way, but it has never been directly seen. Now astronomers have predicted what the first pictures of this black hole will look like when taken with technology soon to be available.
In particular, researchers have found that pictures of a black hole ― or, more precisely, the boundaries around them ― will take a crescent form, rather than the blobby shape that is often predicted. Read more…
We’ve found small black holes and we’ve found really, really big black holes. But what about the “inbetweener” black holes?
The very existence of this class of black hole is disputed, but a Japanese group of astronomers have found the potential locations of three intermediate black hole (IMBH) candidates inside previously unknown star clusters near the center of the Milky Way.
But what are IMBHs and why are they so important?
Image: Artist’s impression of one of the star clusters containing an IMBH. Credit: Keio University
Forget the Large Hadron Collider (LHC) near Geneva, Switzerland, if you really want to unravel the mysteries behind the most elusive subatomic particles in the Universe, you may be better off detecting the gravitational waves radiating from a black hole.
This sci-fi-sounding notion comes from the fertile minds of Vienna University of Technology scientists who argue that the extreme gravitational dominance of black holes may be honeypots for hypothetical exotic particles called axions.
Taking a picture of a black hole, an object so gravitationally bound that not even photons of light can escape, sounds like an oxymoron, but astronomers this week will attempt to do just that.
What they’re hoping to glimpse is something called the “event horizon” — the swirl of matter and energy that are visible around the rim of the black hole just before it falls into the abyss.
A team of astronomers, headed by Nicholas McConnell of the University of California, Berkeley, used data collected by the Hubble Space Telescope, the Keck and Gemini observatories in Hawaii, and the McDonald Observatory in Texas to observe the stars orbiting around the central nuclei of both galaxies and calculated the mass of the black holes hidden in their cores.
By measuring the speed at which these stars were traveling around the invisible mass in the center, an accurate gauge on the black holes’ masses could be arrived at.
One topic that people always ask astronomers about is black holes. These seemingly mysterious and bizarre objects are known to gobble up everything around them, even light, and physics as we know it cannot accurately describe what goes on inside.
From the outside, however, we consider black holes to be pretty simple objects, described completely by their mass, or size, spin and charge. This is often called the “no-hair” theorem of black holes.
For the most part, something that massive is almost certainly neutral, so astronomers really only care about how big a black hole is and how fast it is spinning.
As you might imagine, actually measuring these quantities can be a bit tricky.