Black hole at the center of our galaxy appears to be getting hungrier

Black hole at the center of our galaxy appears to be getting hungrier
Rendering of a star called S0-2 orbiting the supermassive black hole at the center of the Milky Way. It did not fall in, but its close approach could be one reason for the black hole's growing appetite. Credit: Artist's rendering by Nicolle Fuller/National Science Foundation

The enormous black hole at the center of our galaxy is having an unusually large meal of interstellar gas and dust, and researchers don't yet understand why.

"We have never seen anything like this in the 24 years we have studied the ," said Andrea Ghez, UCLA professor of physics and astronomy and a co-senior author of the research. "It's usually a pretty quiet, wimpy black hole on a diet. We don't know what is driving this big feast."

A paper about the study, led by the UCLA Galactic Center Group, which Ghez heads, is published today in Astrophysical Journal Letters.

The researchers analyzed more than 13,000 observations of the black hole from 133 nights since 2003. The images were gathered by the W.M. Keck Observatory in Hawaii and the European Southern Observatory's Very Large Telescope in Chile. The team found that on May 13, the area just outside the black hole's "point of no return" (so called because once matter enters, it can never escape) was twice as bright as the next-brightest observation.

They also observed large changes on two other nights this year; all three of those changes were "unprecedented," Ghez said.

The brightness the scientists observed is caused by radiation from gas and dust falling into the black hole; the findings prompted them to ask whether this was an extraordinary singular event or a precursor to significantly increased activity.

"The big question is whether the black hole is entering a new phase—for example if the spigot has been turned up and the rate of gas falling down the black hole 'drain' has increased for an extended period—or whether we have just seen the fireworks from a few unusual blobs of gas falling in," said Mark Morris, UCLA professor of physics and astronomy and the paper's co-senior author.

The team has continued to observe the area and will try to settle that question based on what they see from new images.

"We want to know how grow and affect the evolution of galaxies and the universe," said Ghez, UCLA's Lauren B. Leichtman and Arthur E. Levine Professor of Astrophysics. "We want to know why the supermassive hole gets brighter and how it gets brighter."

The new findings are based on observations of the black hole—which is called Sagittarius A*, or Sgr A*—during four nights in April and May at the Keck Observatory. The brightness surrounding the black hole always varies somewhat, but the scientists were stunned by the extreme variations in brightness during that timeframe, including their observations on May 13.

"The first image I saw that night, the black hole was so bright I initially mistook it for the star S0-2, because I had never seen Sagittarius A* that bright," said UCLA research scientist Tuan Do, the study's lead author. "But it quickly became clear the source had to be the black hole, which was really exciting."

One hypothesis about the increased activity is that when a star called S0-2 made its closest approach to the black hole during the summer 2018, it launched a large quantity of gas that reached the black hole this year.

Another possibility involves a bizarre object known as G2, which is most likely a pair of binary stars, which made its closest approach to the black hole in 2014. It's possible the black hole could have stripped off the outer layer of G2, Ghez said, which could help explain the increased brightness just outside the black hole.

Morris said another possibility is that the brightening corresponds to the demise of large asteroids that have been drawn in to the black hole.

No danger to Earth

The black hole is some 26,000 light-years away and poses no danger to our planet. Do said the radiation would have to be 10 billion times as bright as what the astronomers detected to affect life on Earth.

Astrophysical Journal Letters also published a second article by the researchers, describing speckle holography, the technique that enabled them to extract and use very faint information from 24 years of data they recorded from near the black hole.

Ghez's research team reported July 25 in the journal Science the most comprehensive test of Einstein's iconic general theory of relativity near the black hole. Their conclusion that Einstein's theory passed the test and is correct, at least for now, was based on their study of S0-2 as it made a complete orbit around the black hole.

Ghez's team studies more than 3,000 stars that orbit the supermassive black hole. Since 2004, the scientists have used a powerful technology that Ghez helped pioneer, called adaptive optics, which corrects the distorting effects of the Earth's atmosphere in real time. But speckle holography enabled the researchers to improve the data from the decade before adaptive optics came into play. Reanalyzing data from those years helped the team conclude that they had not seen that level of brightness near the black hole in 24 years.

"It was like doing LASIK surgery on our early images," Ghez said. "We collected the data to answer one question and serendipitously unveiled other exciting scientific discoveries that we didn't anticipate."


Explore further

Einstein's general relativity theory is questioned but still stands for now

More information: Tuan Do et al. Unprecedented Near-infrared Brightness and Variability of Sgr A*, The Astrophysical Journal (2019). DOI: 10.3847/2041-8213/ab38c3

Zhuo Chen et al. Consistency of the Infrared Variability of SGR A* over 22 yr, The Astrophysical Journal (2019). DOI: 10.3847/2041-8213/ab3c68

Citation: Black hole at the center of our galaxy appears to be getting hungrier (2019, September 11) retrieved 18 September 2019 from https://phys.org/news/2019-09-black-hole-center-galaxy-hungrier.html
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Sep 11, 2019
That's what Beowulf Shaeffer said.

Sep 11, 2019
In search of black holes and dark matter astrophysicists are relying on indirect observations. It would seem that the measurement of the event horizon of a black hole directly would be a direct evidence. However, by the nature of a horizon, any real measurement of the event horizon will be indirect. The Event Horizon Telescope will get picture of the silhouette of the Sgr A* which is due to optical effects of spacetime outside of the event horizon. The result will be determined by the simple quality of the resulting image that does not depend on the properties of the spacetime within the image. So, it will be also indirect and an existence of BH is a hypothesis.
https://www.acade...ilky_Way

Sep 11, 2019
Words mean everything, but the rule may have been disregarded when it was said:
""The first image I saw that night, the black hole was so bright I initially mistook it for the star S0-2, because I had never seen Sagittarius A* that bright,"...

He said that the 'Black Hole' was so bright. Is this a problem with English, or did he really SEE the Black Hole? But we were told that only the Event Horizon and the jets could be detected. Who is the confused one here?

Sep 11, 2019
In search of black holes


observation
hypothesis
prediction
experimentation
conclusion

the predictions match the observations. black holes exist. Einstein right again. Q.E.D.

Sep 11, 2019
"Black hole at the center of our galaxy appears to be getting hungrier"

It's always hungry, so hungry in fact that it eats itself alive as being the reason we have never seen it.

Sep 11, 2019
Notice that this time they did not dare mention that the brightening is occurring only in the near in-fared, as briefly noted earlier in:

https://phys.org/...ght.html

That is likely because they have no explanation. And it points to the disturbing idea of 'gravitational redshift' from the brightening occurring at the superdense star's surface, and not at some fanciful event horizon, an idea so irresistably sexy that modern cosmologists cannot take their wistful eyes off of. Their foggy brains are simply blinded by sexy, but stupid ideas. Yes, perhaps under extreme gravity, light does gets tired. Such a condition cannot be easily replicated on Earth. That does not mean it cannot exist elsewhere.

Sep 11, 2019
Astronomers don't know why gas and stars seem to be getting shredded by our galaxies central supermassive black hole . . .

Sep 11, 2019
Words mean everything, but the rule may have been disregarded when it was said:
""The first image I saw that night, the black hole was so bright I initially mistook it for the star S0-2, because I had never seen Sagittarius A* that bright,"...

He said that the 'Black Hole' was so bright. Is this a problem with English, or did he really SEE the Black Hole? But we were told that only the Event Horizon and the jets could be detected. Who is the confused one here?
Obviously , the reference was to the Event Horizon. Stop playing stupid.

Sep 11, 2019
I don't know what it is that every article on black holes brings out the crackpots and demented who want to go on and on about dynamic plasma's and gravitestimals and what not. It's like a siren song for the crazies amongst us.

I think what happens is that some people overdose on science fiction when they are children. For those with patience, ability, and true curiosity, that simulates a genuine desire for education and knowledge. For the really stupid or drug-addled, it tips them into hallucinogenic madness. All I know is I wish the crackpots would go away.

I will make one comment amount that, however. Once when I was in college in a fevored dream I became convinced I had solved the 4 color map theorem. It took several hours by a few dedicated graduate students to convince me I was wrong. I can see now that I could easily have spent my entire life pursuing that idiocy had I not been willing to listen.

Sep 11, 2019
LOL.

PS. C is not the speed limit you seem to think it is.

Sep 12, 2019
Their foggy brains are simply blinded by sexy, but stupid ideas. Yes, perhaps under extreme gravity, light does gets tired. Such a condition cannot be easily replicated on Earth. That does not mean it cannot exist elsewhere.


Tired light! Lol. Ruled out in umpteen ways. Dead. Only believed by gullible cranks.

Sep 12, 2019
"Black hole at the center of our galaxy appears to be getting hungrier"

It's always hungry, so hungry in fact that it eats itself alive as being the reason we have never seen it.


Why does this idiot keep posting? There is a clue in the name as to why you'll never 'see' a BH, dumbo. We have, however, seen the predicted event horizon. Ergo, BHs exist. 100%.

Sep 12, 2019
LOL.

PS. C is not the speed limit you seem to think it is.


Yes it is. So, unless you have a link to some real science saying otherwise, we can, and will, safely ignore your comment.

Sep 12, 2019
"The flaring is not visible in optical light. It's all happening in the near-infrared, the portion of the infrared spectrum closest to optical light. Astronomers have been watching Sgr. A* for 20 years, and though the black hole does have some variability in its output, this flaring event is like nothing astronomers have observed before. This peak was over twice as bright as the previous peak flux level."

https://phys.org/...ght.html

I'm always reminded about WHY overlooking such pertinent details just who these so-called scientist astronomers think they're trying to kid?

If there is truly uncharacteristic phenomena occuring in such a small area of the galaxy, why then is it not exhibited in ALL wavelengths of the electro-magnetic spectrum? Astronomers can't answer this question because they know so little about nuclear physics that they get lost just trying to comprehend the concept of the 14.7 minute Lifetime Decay Rate of a free neutron.

Sep 12, 2019
@Benni
Why would you expect to see "ALL wavelengths of the electro-magnetic spectrum?"?

What details are they "overlooking"?


Sep 12, 2019
I don't think @Benni gets spectra, nor ever will.

Despite having used a radio or television both of which finely divide the radio spectrum.

So, @Benni, tell us, can you detect gamma rays with a television?

Sep 12, 2019
@Benni
You still think a free neutron decays at exactly 14.7 minutes?

Solve this differential equation for us: dg/dz = z + z/2


Sep 12, 2019
@Benni
You still think a free neutron decays at exactly 14.7 minutes?

Solve this differential equation for us: dg/dz = z + z/2
.....math is NOT NUCLEAR PHYSICS jimbo (schneibo). It is an observational fact that the Beta particle decay rate of a free unbound neutron is 14.7 minutes no matter how hard you try obfuscating that point of fact.

There is no PROBABILITY CURVE to the 14.7 minute beta particle decay rate of a free unbound neutron, if you imagine it's different than 14.7 minutes then provide the OBSERVATIONAL PROOF, maybe some data from the Hadron Collider?


Sep 12, 2019
@Benni
You still think a free neutron decays at exactly 14.7 minutes?

Solve this differential equation for us: dg/dz = z + z/2
.....math is NOT NUCLEAR PHYSICS jimbo (schneibo). It is an observational fact that the Beta particle decay rate of a free unbound neutron is 14.7 minutes no matter how hard you try obfuscating that point of fact.

There is no PROBABILITY CURVE to the 14.7 minute beta particle decay rate of a free unbound neutron, if you imagine it's different than 14.7 minutes then provide the OBSERVATIONAL PROOF, maybe some data from the Hadron Collider?



Errrrr, lying much? You have already been shown the observational evidence. In the scientific literature. Multiple times. Including piccies for the hard of thinking.

Sep 12, 2019
@Benni
Why would you expect to see "ALL wavelengths of the electro-magnetic spectrum?"?

What details are they "overlooking"?
......the rest of the electro-magnetic spectrum.

If all this "flaring" is of such unusual significance, why only at one tiny portion of the EM Spectrum does it occur?

Do you even know what Earth's atmospheric lightning emits? Every single wavelength all the way up to gamma, so why does something supposedly of such stupendous energy emission have such a limited wavelength generation of energy?

Any object free-falling through gravity is not limited to giving up energy at only one wavelength, as it picks up free falling velocity the energy level of the object will shift to higher energy levels (shorter wavelength), a hard concept of nuclear physics I wouldn't expect Astronomers to comprehend, let alone yourself jimbo.

Sep 12, 2019
This comment has been removed by a moderator.

Sep 12, 2019
@Benni

You are still an idiot.
.......but you couldn't refute the factual basis of my Comment.

Sep 12, 2019
@Benni

Please quote the factual basis of your comment.

Sep 12, 2019
The very center of our Galaxy in the core of the bulge is located in the direction of the constellation Sagittarius. The dust gets thicker and thicker as we look into the center of the Galaxy, so the ***best options for observing the Galactic center are in radio waves and in infrared light.***.....................
...........However, ***astronomers have used many different types of observations at different wavelengths*** in an effort to reveal even more about the Galactic Center. For example, the below image from the ***Chandra X-Ray Observatory***, taken by Penn State Professor Emeritus Gordon Garmire's team, reveals that Sgr A can be further reduced to a few sources, including a bright, small source called Sgr A*:


https://www.e-edu..._p7.html


Sep 12, 2019
Overview and interesting resources for Penn State University's ASTRO 801 Master's level course;

https://www.e-edu...ode/1559

Sep 12, 2019
@Benni

You are still an idiot.
.......but you couldn't refute the factual basis of my Comment.


Let me rephrase my comment as, "What you are saying is idiotic.". How's that Mods who do nothing.

Sep 12, 2019
@Benni

Please quote the factual basis of your comment.


Any object free-falling through gravity is not limited to giving up energy at only one wavelength, as it picks up free falling velocity the energy level of the object will shift to higher energy levels (shorter wavelength), a hard concept of nuclear physics I wouldn't expect Astronomers to comprehend, let alone yourself jimbo.

Sep 12, 2019
This is a click bait headline designed for click bait suckers. Move along people. nothing to see here except some fake scientists who wet their pants.

Sep 13, 2019
C is the photon "snap" speed back to it's zero weight space caused by proton destruction.
A photon released from a dark mass aperture trap, will keep accelerating until it finds it's zero weight space, possibly much faster than C.

Sep 13, 2019
Any object free-falling through gravity is not limited to giving up energy at only one wavelength, as it picks up free falling velocity the energy level of the object will shift to higher energy levels (shorter wavelength), a hard concept of nuclear physics I wouldn't expect Astronomers to comprehend, let alone yourself jimbo.


The very center of our Galaxy in the core of the bulge is located in the direction of the constellation Sagittarius. The dust gets thicker and thicker as we look into the center of the Galaxy, so the ***best options for observing the Galactic center are in radio waves and in infrared light.***.....................
...........However, ***astronomers have used many different types of observations at different wavelengths*** in an effort to reveal even more about the Galactic Center.


https://www.e-edu..._p7.html

Forgotten already? Repeating the same mistake over and over is not going to make it true!


Sep 13, 2019
@Benni

Please quote the factual basis of your comment.


Any object free-falling through gravity is not limited to giving up energy at only one wavelength, as it picks up free falling velocity the energy level of the object will shift to higher energy levels (shorter wavelength), a hard concept of nuclear physics I wouldn't expect Astronomers to comprehend, let alone yourself jimbo.

Unless it is slowed or even stopped somewhere in that "freefall"...

Sep 14, 2019
This comment has been removed by a moderator.

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