Posted on 10/21/2022 10:34:48 AM PDT by Red Badger
The discovery of a so-called monster black hole that has about 12 times the mass of the sun is detailed in a new Astrophysical Journal research submission, the lead author of which is Dr. Sukanya Chakrabarti, a physics professor at The University of Alabama in Huntsville (UAH).
“It is closer to the sun than any other known black hole, at a distance of 1,550 light years,” says Dr. Chakrabarti, the Pei-Ling Chan Endowed Chair in the Department of Physics at UAH, a part of the University of Alabama System. “So, it's practically in our backyard.”
Black holes are seen as exotic because, although their gravitational force is clearly felt by stars and other objects in their vicinity, no light can escape a black hole so they can’t be seen in the same way as visible stars.
“In some cases, like for supermassive black holes at the centers of galaxies, they can drive galaxy formation and evolution,” Dr. Chakrabarti says.
“It is not yet clear how these noninteracting black holes affect galactic dynamics in the Milky Way. If they are numerous, they may well affect the formation of our galaxy and its internal dynamics.”
To find the black hole, Dr. Chakrabarti and a national team of scientists analyzed data of nearly 200,000 binary stars released over the summer from the European Space Agency’s Gaia satellite mission.
“We searched for objects that were reported to have large companion masses but whose brightness could be attributed to a single visible star,” she says. “Thus, you have a good reason to think that the companion is dark.”
Interesting sources were followed up with spectrographic measurements from various telescopes, including the Automated Planet Finder in California, Chile’s Giant Magellan Telescope and the W.M. Keck Observatory in Hawaii.
“The pull of the black hole on the visible sun-like star can be determined from these spectroscopic measurements, which give us a line-of-sight velocity due to a Doppler shift,” says Dr. Chakrabarti. A Doppler shift is the change in frequency of a wave in relation to an observer, like how the pitch of a siren’s sound changes as an emergency vehicle passes.
“By analyzing the line-of-sight velocities of the visible star – and this visible star is akin to our own sun – we can infer how massive the black hole companion is, as well as the period of rotation, and how eccentric the orbit is,” she says. “These spectroscopic measurements independently confirmed the Gaia solution that also indicated that this binary system is composed of a visible star that is orbiting a very massive object.”
The cross-hairs mark the location of the newly discovered monster black hole.
Sloan Digital Sky Survey / S. Chakrabart et al.
The black hole has to be inferred from analyzing the motions of the visible star because it is not interacting with the luminous star. Noninteracting black holes don’t typically have a doughnut-shaped ring of accretion dust and material that accompanies black holes that are interacting with another object. Accretion makes the interacting type relatively easier to observe optically, which is why far more of that type have been found.
“The majority of black holes in binary systems are in X-ray binaries – in other words, they are bright in X-rays due to some interaction with the black hole, often due to the black hole devouring the other star,” says Dr. Chakrabarti. “As the stuff from the other star falls down this deep gravitational potential well, we can see X-rays.”
These interacting systems tend to be on short-period orbits, she says.
“In this case we're looking at a monster black hole but it's on a long-period orbit of 185 days, or about half a year,” Dr. Chakrabarti says. “It's pretty far from the visible star and not making any advances toward it.”
The techniques the scientists employed should apply to finding other noninteracting systems, as well.
“This is a new population that we're just starting to learn about and will tell us about the formation channel of black holes, so it’s been very exciting to work on this,” says Peter Craig, a doctoral candidate at the Rochester Institute of Technology who is advised on his thesis by Dr. Chakrabarti.
“Simple estimates suggest that there are about a million visible stars that have massive black hole companions in our galaxy,” says Dr. Chakrabarti. “But there are a hundred billion stars in our galaxy, so it is like looking for a needle in a haystack. The Gaia mission, with its incredibly precise measurements, made it easier by narrowing down our search.”
Scientists are trying to understand the formation pathways of noninteracting black holes.
“There are currently several different routes that have been proposed by theorists, but noninteracting black holes around luminous stars are a very new type of population,” Dr. Chakrabarti says. “So, it will likely take us some time to understand their demographics, and how they form, and how these channels are different – or if they're similar – to the more well-known population of interacting, merging black holes.”
With Black Holes?....................
I don't think that's correct. Wikipedia says that stellar-mass black holes can be as small as 5 solar masses. Saying the black hole is 12 solar masses does not mean that the star that produced it was only 12 solar masses; a lot of mass is blown into space by the supernova.
No need to fear black holes.
They’re no better or worse than white holes.
It’s the ‘s-—holes’ that people need to worry about.
A black hole in our backyard?
My wife, who does the grass-cutting, will be worried...
At 84, she worries about everything...
The theory expects that it requires far more mass than that in a burned out star to collapse into a black hole singularity or neutron star… because there is a point at which there is just as much mass pulling away from the singularity center point as their is pulling toward the center point… but they ignore those calculations in identifying what they claim are black holes in what they are seeing in their telescopic observations. They really don’t know what they are seeing. It’s theory, not really proved fact. Until they can find the 97% of the missing matter called “dark matter” and it’s corollary “dark energy” to make their math work, it’s all nose picking, pulling out buggers, examining them, and making pronouncements on what they’ve “discovered” based on flawed theory.
Jjust make it quick and mostly painless. Seems better than suffering thru till the inevitable end.
Oh, my god! She is the governor of Georgia! She regulates what it eats!!!!
Not well, mind you, but does it, anyway, not well… at all…
“The theory expects that it requires far more mass than that in a burned out star to collapse into a black hole singularity or neutron star…”
WRONG! A star 2x the sun can become a neutron star. A star 4x can become a black hole.
Black Hole Denier!..........................
How much time do we have before we get sucked in? Should I wash my underwear one more time or skip it?
Don’t buy any green bananas.........................
“From this paper”
REJECTED
Stephen J. Crothers (1957–) is a handyman/gardener and part-time amateur scientist who claims that black holes do not exist and are neither predicted by nor compatible with General Relativity.[2]
In 2005, Crothers was expelled from the University of New South Wales;
Crothers would soon go on to receive an honorary doctorate degree from the Maxwell Einstein University;[15][16] a fake, make-believe school created by his colleague and partner in crime, Myron Evans, for the sole purpose of doling out phony diplomas to his cohorts and cronies.
In 2008, Crothers and Evans each received a “Gold Medal Award” from the Telesio-Galilei Academy of Science;[17] a lunatic fringe organization that hands out second-rate menial awards to virtually any disreputable crackpot and con artist.
https://rationalwiki.org/wiki/Stephen_J._Crothers
“Black holes are not real and are pure fantasy. They’re fun in movies though.
From this paper”
You believe these crackpots? I hope no one here does.
Any close ups of Uranus?
There are several, up and down the East and West Coasts of America. The biggest is in DC.
Stacey Abrams has been around for awhile... This is old news.
“They’re simply distortions between binary stars. “
Then how are we detecting them where there are no binary stars?
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