Black Holes part 4

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Message 2095411 - Posted: 5 Mar 2022, 22:35:50 UTC

Phenomenon thought to be closest black hole is actually a 'stellar vampire'
Astronomers on Wednesday announced new findings indicating that an interstellar system 1,000 light years away from Earth does not actually include a black hole, a reversal of a previous observation.

If it did exist, the black hole in the HR 6819 system located in the constellation Telescopium would have been the closest to Earth. When a team of researchers examined the movement of two stars in 2020, the first star orbited the second while the second star moved in a wider orbit. They believed there had to be a black hole at the center to explain the pattern.


LINK TO SCIENTISTS DETAILED FINDINGS PAPER
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Message 2096722 - Posted: 29 Mar 2022, 18:22:15 UTC

From the European Space Agency:
Did black holes form immediately after the Big Bang?
How did supermassive black holes form? What is dark matter? In an alternative model for how the Universe came to be, as compared to the ‘textbook’ history of the Universe, a team of astronomers propose that both of these cosmic mysteries could be explained by so-called ‘primordial black holes’.

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Message 2096760 - Posted: 30 Mar 2022, 11:08:19 UTC

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Message 2098824 - Posted: 2 May 2022, 22:28:53 UTC

Hear the Sound of a Black Hole ‘Echo’.

Using a new tool they nicknamed the “Reverberation Machine,” researchers have detected eight echoing black hole binaries in the Milky Way. They then converted those X-ray echoes into sound waves, which you can listen to in the video below.

The Reverberation Machine combed satellite data from NICER, a telescope aboard the International Space Station that studies X-ray emissions from sources like black holes and neutron stars, including a weird type of emission known as an ‘echo.’ In a recent study published in The Astrophysical Journal, a team of astrophysicists describe eight new black hole binary echoes and their X-ray outbursts....
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Message 2099286 - Posted: 11 May 2022, 9:02:33 UTC

Black hole hunters cast gaze at center of the Milky Way galaxy.

...Scientists have been using the Event Horizon Telescope (EHT), a global network of observatories working collectively to observe radio sources associated with black holes, to study this Milky Way denizen and have set an announcement for Thursday that signals they may finally have secured an image of it. The black hole is called Sagittarius A*, or SgrA*....
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Message 2099407 - Posted: 12 May 2022, 19:20:55 UTC - in response to Message 2099286.  

Black hole hunters cast gaze at center of the Milky Way galaxy.

...Scientists have been using the Event Horizon Telescope (EHT), a global network of observatories working collectively to observe radio sources associated with black holes, to study this Milky Way denizen and have set an announcement for Thursday that signals they may finally have secured an image of it. The black hole is called Sagittarius A*, or SgrA*....
And now here's that pic.

Gaze upon the supermassive black hole at the center of our galaxy.

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Message 2101385 - Posted: 15 Jun 2022, 21:59:18 UTC

There’s a Black Hole in Our Galaxy With 7 Times More Mass Than the Sun.

Conclusive, measurable observation of a lone black hole occurred for the first time ever, thanks to the Hubble Space Telescope. The $1.2 billion telescope, first launched in 1990, spent six years monitoring a black hole drifting through interstellar space, measuring the object and giving us the first-ever direct evidence of a region in space-time where gravity is so strong that nothing can escape from it.

The newly-famous stellar-mass black hole is a rare one in that it isn’t accompanied by stars, NASA explains in a June 10 press release. It’s wandering about 5,000 light years away in the Carina-Sagittarius spiral arm of our Milky Way galaxy. What’s fascinating here is that Hubble’s measurements gave astronomers direct access to evidence of the black hole—instead of relying on inferred statistics or data from binary-system interactions.

Black holes free-floating in the Milky Way are relatively rare. For a black hole to form in the first place, a monstrous star at least 20 times larger than Earth’s sun—NASA says less than one-thousandth of the galaxy’s stellar population fits the criteria—must explode (think: supernova). From there, the “remnant core is crushed by gravity into a black hole,” according to the NASA release. Following the detonation, the black hole may start traveling the galaxy, a move the space agency likens to a “blasted cannonball.”

Photographing a black hole isn’t possible because there’s no light. What we do see, though, is the warping of space around it, deflecting and amplifying starlight from anything that momentarily lines up exactly behind the black hole...
Scientists Identify The Fastest-Growing Black Hole Ever Found in The Recent Universe.

A supermassive black hole growing so fast it shines 7,000 times brighter than the entire Milky Way has just been found, hiding in plain sight.

Every second, an amount of material equivalent to the mass of Earth falls into this insatiable black hole.

As far as we know, it's the fastest-growing black hole of the last 9 billion years – its activity so frenzied that it sends multi-wavelength light blazing across the Universe, making it what's known as a quasar.

The black hole is called SMSS J114447.77-430859.3 – J1144 for short – and an analysis of its properties suggests that the light from its feeding has traveled some 7 billion years to reach us, and that it clocks in at around 2.6 billion times the mass of the Sun (quite a respectable size for a supermassive black hole).

And there it was, just hanging out, lurking unnoticed until now. But because of where it sits – 18 degrees above the galactic plane – previous surveys looking for quasars have just managed to miss it, only skimming as close as 20 degrees above the disk of the Milky Way.

"A bit of historical bad luck has become our good luck," astronomer Christopher Onken from the Australian National University told ScienceAlert.

"Searches for distant objects get very difficult when you look close to the disk of the Milky Way – there are so many foreground stars that it's very hard to find the rare background sources.

"Another team used an ultraviolet satellite to search for these luminous objects across the whole sky, but J1144 fell into a small gap in their coverage. But the source is bright enough that it appears in photographs taken of the sky as far back as 1901, so it's definitely a case of hiding in plain sight."...
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Message 2102056 - Posted: 26 Jun 2022, 20:29:48 UTC

'Rogue black holes' might be neither 'rogue' nor 'black holes'.

When a star 20 times as massive as our sun dies, it can explode in a supernova and squeeze back down into a dense black hole (with gravity's help). But that explosion is never perfectly symmetrical, so sometimes, the resulting black holes goes hurtling off into space. These wandering objects are often called “rogue black holes” because they float around freely, untethered by other celestial bodies.

But that name might be a “misnomer,” according to Jessica Lu, associate professor of astronomy at the University of California Berkeley. She prefers the term “free-floating” to describe these black holes. “Rogue,” she says, implies that the nomads are rare or unusual—or up to no good.

That's certainly not the case. Astronomers estimate that there are as many as 100 million such black holes that roam around our galaxy. But because they’re solitary, they're extremely difficult to find. Until recently, these so-called rogue black holes were only known through theory and calculations....
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Message 2104785 - Posted: 9 Aug 2022, 20:29:03 UTC

Solving the Hawking Paradox: What Happens When Black Holes Die?

In what is arguably his most significant contribution to science, Stephen Hawking suggested that black holes can leak a form of radiation that causes them to gradually ebb away, and eventually end their lives in a massive explosive event.

This radiation, later called “Hawking radiation,” inadvertently causes a problem at the intersection of general relativity and quantum physics— the former being the best description we have of gravity and the universe on cosmically massive scales, while the latter is the most robust model of the physics that governs the very small.

The two theories have been confirmed repeatedly since their distinct inceptions at the start of the 20th century. Yet, they remain frustratingly incompatible.

This incompatibility, which mainly arises from the lack of a theory of “quantum gravity,” was compounded in the mid-1970s when Hawking took the principles of quantum physics and applied them to the edge of black holes. A paradox was born that physicists have been working for 50 years to solve.

We may finally be on the verge of a solution thanks to review published in the journal Europhysics Letters last month. In it, University of Sussex physics researchers Xavier Calmet and Stephen D. H. Hsu detail the problem of the Hawking paradox and potential solutions to this cosmological problem....
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Message 2108438 - Posted: 13 Oct 2022, 9:43:38 UTC

Curious Black Hole Crash in Deep Space Leaves Astrophysicists Puzzled.

Black hole collisions are some of the most extreme phenomena in the universe. As the two massive, invisible bodies spiral toward each other, they disturb the fabric of spacetime, sending out ripples across the universe. Those ripples -- gravitational waves -- eventually wash over the Earth, where some very sensitive detectors in the US, Italy and Japan can "hear" them.

One such ripple washed over our planet in the early hours of Jan. 29, 2020. It was picked up by the dual detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) in the US and a third detector, Virgo, in Italy. The detectors' characteristic chirp suggested a pair of black holes, one that was around 40 times the mass of the sun and the other 22 times, had smashed together....
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Message 2108450 - Posted: 13 Oct 2022, 17:33:24 UTC

Black hole spews out material years after shredding star.

A black hole has been spotted ejecting material three years after consuming a star, in what astronomers are comparing to a cosmic burp.

Ordinarily, this sort of phenomenon would be witnessed during the event, and the Harvard University researchers are still unsure why the delay has occurred.

They monitored the black hole for several months after it had devoured the small star in 2018, but by chance decided to revisit it in 2021.

That was when they detected radio waves that were violently spewing out of it, as if it was 'burping out a bunch of material from the star it ate years ago'....
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Message 2108552 - Posted: 14 Oct 2022, 22:51:05 UTC

Supernova "early-warning system" developed to pinpoint the moment massive stars will explode
... Until now, it's been difficult for scientists to observe the moment a star explodes. But for the first time, researchers have simulated that sudden journey to a star's demise. Researchers found that in a star's "red supergiant" phase – the last phase of its life – dense material accumulates around it and the star becomes drastically dimmer.
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Message 2109737 - Posted: 6 Nov 2022, 19:57:55 UTC

Astrophysicists Discover Closest Black Hole to Earth.

Scientists have discovered a relatively small black hole lurking next to a star in the constellation Ophiuchus, about 1,600 light-years away. It’s now the closest-known back hole to Earth.

Black holes are the densest objects in our universe (sorry, neutron stars). Whether they’re small, stellar-mass black holes or the supermassive ones at the centers of galaxies, the objects have gravitational fields so intense that not even photons of light can escape their event horizons.

The recently discovered black hole—named Gaia BH1—is three times closer to Earth than the previous record holder. Details about its discovery, as well as about the Sun-like star orbiting it, were published this week in the Monthly Notices of the Royal Astronomical Society.

The object was discovered using the Gemini North telescope in Hawaii, part of the International Gemini Observatory, in conjunction with data from the ESA’s Gaia spacecraft. The Gaia data suggested the star’s motion was slightly strange for a single object; it appeared as if the gravity of a massive object were affecting its motion.

Follow-up observations by Gemini North were done to determine the precise orbital period of the companion star, helping the team better estimate the mass of the unseen object....
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Message 2109942 - Posted: 10 Nov 2022, 22:01:49 UTC

That's 1 way to get attention.

Black hole announces itself to astronomers by violently ripping apart a star.

A hitherto undiscovered black hole announced its presence to astronomers when it ripped apart and devoured a star that wandered too close to it.

The intermediate-mass black hole located in a dwarf galaxy a million light-years from Earth shredded the star in an occurrence that astronomers call a Tidal Disruption Event (TDE). The TDE made itself visible when it blasted out a flare of radiation so powerful that it briefly outshone every star in its dwarf galaxy home combined...
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Message 2112961 - Posted: 13 Jan 2023, 20:33:47 UTC

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Message 2113012 - Posted: 14 Jan 2023, 20:38:55 UTC

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Message 2115089 - Posted: 22 Feb 2023, 7:39:34 UTC

Spotted on the run.

'Runaway' black hole the size of 20 million suns found speeding through space with a trail of newborn stars behind it.

...The researchers discovered the runaway black hole as a bright streak of light while they were using the Hubble Space Telescope to observe the dwarf galaxy RCP 28, located about 7.5 billion light-years from Earth.

Astronomers have spotted a runaway supermassive black hole, seemingly ejected from its home galaxy and racing through space with a chain of stars trailing in its wake....
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Message 2116796 - Posted: 29 Mar 2023, 7:24:17 UTC

British scientists discover ultramassive black hole ‘30bn times the mass of the Sun’.

An ultramassive black hole around 33 billion times the mass of the Sun has been discovered by astronomers in the UK.

Scientists from Durham University said the gargantuan black hole is one of the biggest ever found.

The team described its findings, published in the journal Monthly Notices of the Royal Astronomical Society, as “extremely exciting”.

Lead author Dr James Nightingale, of the Department of Physics at Durham University, said: “This particular black hole, which is roughly 30 billion times the mass of our Sun, is one of the biggest ever detected and on the upper limit of how large we believe black holes can theoretically become, so it is an extremely exciting discovery.”....
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Message 2130424 - Posted: 27 Dec 2023, 13:46:28 UTC

A bizarre galaxy NASA spotted at the edge of the universe could upend what we know about supermassive black holes.

Scientists have long wondered how supermassive black holes — the enormous, mysterious phenomena at the center of galaxies including our Milky Way — came into existence.

A new observation of Galaxy UHZ-1, collected by NASA using its powerful new James Webb Space Telescope and the Chandra X-ray Observatory, suggests an unusual origin.

Per the agency, it could show that the supermassive black hole there was born directly from clouds of primordial gas.

If confirmed, it would show, for the first time, that supermassive black holes are not always formed by dying stars.

Such a discovery "changes the game in understanding how these objects formed," said study lead author Priyamvada Natarajan while speaking to Science Friday, a non-profit science-education organization.

"It is simply too big too early. It's like looking in at a kindergarten classroom and there among all the 5-year-olds is one that is 150 pounds and/or six feet tall," Daniel Holz, a theorist at the University of Chicago who studies black holes, told The New York Times.....
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Message 2132786 - Posted: 19 Feb 2024, 18:23:30 UTC

Now that's 1 hungry black hole.

Astronomers find what may be the universe's brightest object with a black hole devouring a sun a day.

Astronomers have discovered what may be the brightest object in the universe, a quasar with a black hole at its heart growing so fast that it swallows the equivalent of a sun a day.

The record-breaking quasar shines 500 trillion times brighter than our sun. The black hole powering this distant quasar is more than 17 billion times more immense than our sun, an Australian-led team reported Monday in the journal Nature Astronomy.

While the quasar resembles a mere dot in images, scientists envision a ferocious place.

The rotating disk around the quasar's black hole — the luminous swirling gas and other matter from gobbled-up stars — is like a cosmic hurricane.

“This quasar is the most violent place that we know in the universe,” lead author Christian Wolf of Australian National University said in an email.

The European Southern Observatory spotted the object, J0529-4351, during a 1980 sky survey, but it was thought to be a star. It was not identified as a quasar — the extremely active and luminous core of a galaxy — until last year. Observations by telescopes in Australia and Chile’s Atacama Desert clinched it......
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Message boards : Science (non-SETI) : Black Holes part 4


 
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