A thick accretion disk swirls around the maw of a supermassive black hole in an illustration. Flashes of x-ray light from the disk create "echoes" that scientists can use to map its inner structure beyond what any telescope can directly observe.
* * *
In an enormous effort that stunned the world, scientists last year unveiled the first direct picture of a black hole , allowing humans to see what exists at the cusp of the monster's maw. Now, astronomers have used a different technique involving x-ray "echoes" to peer even closer at one of these gravitational behemoths.
Quite a lot has been going on:
What are black holes? | Space | EarthSky
The 1st-ever direct image of a black hole, released by scientists in April 2019. The image shows a bright ring formed as light bends in the intense gravity around this black hole, which is 6.5 billion times more massive than our sun. This black hole is located in the center of the galaxy M87, 55 million light-years from Earth. Image via Event Horizon Telescope Collaboration .
A black hole is an area of space with a gravitational field so strong that nothing, not even light, can escape it. That’s why black holes appear black. In some cases, black holes are former massive stars that have been crushed to an extreme density during supernova explosions. In other cases, black holes contain the mass of millions or billions of stars.
'Giant, shape-shifting stars' spotted near Milky Way's black hole | Science | The Guardian
A number of bizarre shape-shifting objects have been discovered close to the supermassive black hole at the centre of the Milky Way.
The blobs are thought to be giant stars that spend part of their orbits so close to the black hole that they get stretched out like bubble gum before returning to a compact, roughly spherical form.
"These objects look like gas and behave like stars," said Andrea Ghez, a professor of astrophysics at the University of California Los Angeles and a co-author of the paper.
Astronomers use 'cosmic echolocation' to map black hole surroundings
As material spirals towards a black hole, it is heated up and emits X-rays that, in turn, echo and reverberate as they interact with nearby gas. These regions of space are highly distorted and warped due to the extreme nature and crushingly strong gravity of the black hole.
Now, researchers have used the European Space Agency's XMM-Newton X-ray observatory to track these light echoes and map the surroundings of the black hole at the core of an active galaxy. Their results are reported in the journal Nature Astronomy .
Other things to check out:
Drag racing and black hole physics | symmetry magazine
The silver Mustang was fishtailing, its back wheels losing traction and spinning out on the wet pavement of the New England Dragway.
On a cold and damp October night at the quarter-mile racetrack in the small town of Epping, New Hampshire, Joseph Farah was careening at over 100 miles per hour when he lost control of the car.
* * *
For several days Farah had been wracking his brain about the technicalities of how dark shadows form at the middle of black holes. The project was the culmination of his first deep dive into black hole theory and involved quite a bit of complex thinking.
Black hole discovery: Space anomaly lets astronomers find millions of black holes | Science |
But a team of astronomers in Poland could be on the verge of revolutionising black hole discoveries thanks to an anomaly known as Gaia16aye.
Gaia16aye is a binary star system where a star about half the mass of the Sun is joined by an even smaller star.
According to Dr Łukasz Wyrzykowski of the University of Warsaw’s Astronomical Observatory, the binary system is too faint to be seen from Earth.
But the astronomer and his colleagues have used so-called gravitational microlensing to observe the stars for the very first time.
Four strange new objects found around the Milky Way's huge black hole | Astronomy.com
Astronomers have discovered four new and mysterious objects orbiting the Milky Way's supermassive black hole, Sagittarius A*. The bizarre objects look a lot like common clouds of gas and dust, but they surprisingly manage to stay compact like stars as they run laps around our galaxy's gargantuan black hole.
The quartet of new objects share striking similarities with two others, dubbed G1 and G2, that were found in the past 15 years or so. This has led researchers to conclude the four new bodies likely belong to the same class of objects as G1 and G2, which are simply referred to as G-sources or G-objects.
"Black Hole Enigma" --Could the Discovery Be a Massive Neutron Star? | The Daily Galaxy
Home » Astronomy » “Black Hole Enigma” –Could the Discovery Be a Massive Neutron Star?
* * *
Our knowledge of black holes has grown exponentially since Princeton quantum physicist John Wheeler first named these enigmatic monsters in 1967, observing that “the laws of physics that we regard as 'sacred,' as immutable, are anything but." Observations have shown that stellar black holes typically have masses of about ten times that of the Sun, in accordance with the theory of stellar evolution.
Happening on Twitter
Scientists were able to map the region around a distant black hole's event horizon in unprecedented detail https://t.co/2BJn3U21CK NatGeo (from Global) Mon Jan 20 16:38:27 +0000 2020
By the 1990s, astronomers had proved that black holes existed in the real universe. In 2019, we got our first gli… https://t.co/uYL90F812o business (from New York and the World) Sat Jan 18 02:54:23 +0000 2020
No comments:
Post a Comment