The black hole is not the biggest that is known, but is far bigger than scientist would expect to be at its age. It got to its huge size 875 million years after the big bang – which scientists wouldn’t expect to happen, since black holes grow as they age and eat other gas and stars that surround them.
Scientists can only see it at that age – 12.8 billion years ago, and 6 per cent of the age of the current universe – because it is so far away. They also can’t look at it directly, because the power of its gravity sucks everything including light into it – but the team that found it saw it by spotting a quasar, an object that gets lit up as it’s heading into the black hole. In a paper reporting their finding, published in Nature and reported in National Geographic, the scientists behind the study say that the finding could change our understanding of how black holes form. It is thought that black holes begin when the first stars collapsed, about 100 million years after the big bang, and that they swelled after that.
But the newly-found black hole is too big to have happened that way, according to Bram Venemans of the Max Planck Institute for Astronomy, who writes a commentary on the new study.
Other possibilities include a merging of galaxies, bringing two different black holes together. But that depends on the two having the same mass, or they would have cast each other aside rather than merging.
Instead, it’s possible that the first stars that helped create those black holes were huge – as much as a million suns packed into one star. If they collapsed early on, they could have “they could jump-start the formation of very large black holes,” said Loeb.
While that would explain the surprising formulation of the newly-discovered black hole, it depends on such huge stars ever existing. Scientists hope that they can find out whether they did when they send the new James Webb Space Telescope into orbit in 2018
When is it?
March 20. In the UK, it will begin at 8.45am. It will peak at 9.31am before finishing at 10.41am.
Where will be best to see it?
Head north.
The eclipse will be total – covering the sun entirely – in the Faroe Islands and Norwegian island Svalbard. Those will be the only populated places on Earth where it can be seen in its full darkness. But certain parts of Scotland will be almost fully blacked out. The Isle of Lewis, close to Aird Uig, will see the deepest eclipse, and the rest of north-western Scotland will see over 95 per cent coverage.
The eclipse will get less intense in places further south – though even London will be see about 84 per cent coverage.
What’s special about this one?
While eclipses aren’t that rare, it’s not often that they’re total. That’s when the moon lines up right in front of the sun, obscuring it completely.
How often do eclipses happen?
This is the biggest since 1999, but there’ve been a number in the meantime. Partial eclipses happened in 2006, 2008 and 2011.
After the one in March, the next eclipse will be in 2018, but it’ll be very small.
The next big eclipse will be in 2026, which is expected to cover about the same amount of Britain in darkness.
There won’t be another total eclipse until 2090. That one is expected to be similar to the one in 1999, though it’ll be slightly further north and will happen as the sun sets.
How do I watch it?
You might remember the warnings from 1999: never look straight into the sun. If you do, you can permanently damage the back of your eye – where there are no pain sensors, so you won’t even know that anything’s gone wrong.
The key thing is to get some kind of dimming lens to watch the eclipse through. These will probably be readily available ahead of the event.
Can I photograph it?
The same warnings apply: the lens in your camera, just like your eye, can amplify the brightness of the sun and damage it. So it’s important to get a solar filter to keep it safe.
You can use almost any camera, with a long zoom working best. It’s a good idea to take a number of pictures, because the light can change quickly as the eclipse is happening – the most important thing is to try out different settings and get as many photos as you can.
Is it going to cause any problems?
Energy groups have voiced concerns about the power supply, given so much of it is now made up of solar energy. They have worked to head it off – but concerns remain that systems could see problems as people head into work and the power providers deal with the eclipse.
The eclipse will block out nearly 90 per cent of the sunlight in parts of Europe – with some of Scotland seeing 94 per cent coverage. And the electricity supplies might not be able to take up the strain, since so much of Europe’s power supply now relies on solar energy.
The eclipse will be the most extreme since the famous one in 1999. But then, only 0.1 per cent of the renewable energy supply came from solar – now, 10.5 per cent of the green energy in Europe comes from such sources.
“Solar eclipses have happened before but with the increase of installed photovoltaic energy generation, the risk of an incident could be serious without appropriate countermeasures,” said the European Network of Transmission System Operators for Electricity, a group that ensures energy is distributed properly across Europe.
The blackout will come in the morning of March 20, just as Europe heads into work, putting electricity providers under even more pressure.
It will begin in the UK at 8.45am. The maximum eclipse, when the moon is nearest the middle of the sun, will be at 9.31am. The event will end at 10.41am.
The last major solar eclipse happened in August 1999. That was the first total eclipse since 1990 and the first seen in the UK since 1927.
An unusual, repeating light signal in the distance may be coming from the final stages of a merger between two supermassive black holes. At just a few hundredths of a light-year apart, they could be merging in a mere one million years. An event like this has been predicted based on theory, but has never been observed before, according to a new studypublished in Nature this week.
The supermassive black holes at the center of most large galaxies (including ours) appear to co-evolve with their host galaxies: As galaxies merge, their black holes grow more massive too. Since we can’t actually see black holes, researchers look for their surrounding bands of material called accretion disks, which are produced by the intense pull of the black hole’s gravity. The disks of supermassive black holes can release vast amounts of heat, X-rays, and gamma rays that result in a quasar—one of the most luminous objects in the universe.
Caltech’s Matthew Graham and colleagues noticed the light signal coming from quasar PG 1302-102 while studying variability in quasar brightness using data from the Catalina Real-Time Transient Survey, which continuously monitored 500 million celestial light sources across 80 percent of the sky with three ground telescopes.
The team noticed 20 quasars emitting periodic optical signals, which was unexpected since the light curves of quasars are usually chaotic. (That’s because material from the accretion disk spiral randomly into the black hole.) And of these, PG 1302-102’s clean, strong signal, which repeated every five years or so, stood out. "It has a really nice smooth up-and-down signal, similar to a sine wave, and that just hasn't been seen before in a quasar," Graham explains in a news release.
Quasars typically have one emission line that’s viewed as a symmetric curve. "But with this quasar, it was necessary to add a second emission line with a slightly different speed than the first one in order to fit the data," says study co-author Eilat Glikman of Middlebury College. "That suggests something else, such as a second black hole, is perturbing this system." A supermassive black hole binary was the most likely explanation: Any object that’s less dense than a secondary black hole would be disrupted by the gravity of the primary black hole.
"The end stages of the merger of these supermassive black hole systems are very poorly understood," Graham says. "The discovery of a system that seems to be at this late stage of its evolution means we now have an observational handle on what is going on."
Study co-author Daniel Stern of JPL adds: "The black holes in PG 1302-102 are, at most, a few hundredths of a light-year apart and could merge in about a million years or less.” And when that happens, The New York Times reports, it’ll release as much energy as 100 million supernova explosions.
The cavities shown in the image of galaxy cluster MS0735 above were created by jets of charged particles ejected at nearly light speed from a supermassive black hole weighing nearly a billion times the mass of our Sun lurking in the nucleus of the bright central galaxy. The jets displaced more than one trillion solar masses worth of gas. The power required to displace the gas exceeded the power output of the Sun by nearly ten trillion times in the past 100 million years.
MS0735 is ocated about 2.6 billion light-years away in the constellation Camelopardus. The image represents three views of the region that astronomers have combined into one photograph. The optical view of the galaxy cluster, taken by the Hubble Space Telescope's Advanced Camera for Surveys in February 2006, shows dozens of galaxies bound together by gravity.
Diffuse, hot gas with a temperature of nearly 50 million degrees permeates the space between the galaxies. The gas emits X-rays, seen as blue in the image taken with the Chandra X-ray Observatory in November 2003. The X-ray portion of the image shows enormous holes or cavities in the gas, each roughly 640,000 light-years in diameter -- nearly seven times the diameter of the Milky Way. The cavities are filled with charged particles gyrating around magnetic field lines and emitting radio waves shown in the red portion of image taken with the Very Large Array telescope in New Mexico in June 1993.
Astronomers have discovered a black hole that is consuming gas from a nearby star 10 times faster than previously thought possible. The black hole—known as P13—lies on the outskirts of the galaxy NGC7793 about 12 million light years from Earth and is ingesting a weight equivalent to 100 billion billion hot dogs every minute.
The discovery was published today in the journal Nature.
International Centre for Radio Astronomy Research astronomer Dr Roberto Soria, who is based at ICRAR’s Curtin University node, said that as gas falls towards a black hole it gets very hot and bright. He said scientists first noticed P13 because it was a lot more luminous than other black holes, but it was initially assumed that it was simply bigger.
“It was generally believed the maximum speed at which a black hole could swallow gas and produce light was tightly determined by its size,” Dr Soria said.
“So it made sense to assume that P13 was bigger than the ordinary, less bright black holes we see in our own galaxy, the Milky Way.”
When Dr Soria and his colleagues from the University of Strasbourg measured the mass of P13 they found it was actually on the small side, despite being at least a million times brighter than the Sun. It was only then that they realised just how much material it was consuming.
“There’s not really a strict limit like we thought, black holes can actually consume more gas and produce more light,” Dr Soria said.
Dr Soria said P13 rotates around a supergiant ‘donor’ star 20 times heavier than our own Sun.
He said the scientists saw that one side of the donor star was always brighter than the other because it was illuminated by X-rays coming from near the black hole, so the star appeared brighter or fainter as it went around P13.
“This allowed us to measure the time it takes for the black hole and the donor star to rotate around each other, which is 64 days, and to model the velocity of the two objects and the shape of the orbit," Dr Soria said.
“From this, we worked out that the black hole must be less than 15 times the mass of our Sun.”
Dr Soria compared P13 to small Japanese eating champion Takeru Kobayashi.
“As hotdog-eating legend Takeru Kobayashi famously showed us, size does not always matter in the world of competitive eating and even small black holes can sometimes eat gas at an exceptional rate,” he said.
Dr Soria said P13 is a member of a select group of black holes known as ultraluminous X-ray sources.
“These are the champions of competitive gas eating in the Universe, capable of swallowing their donor star in less than a million years, which is a very short time on cosmic scales,” he said.
Astronomers have just discovered the smallest known galaxy that harbors a huge, supermassive black hole at its core.
The relatively nearby dwarf galaxy may house a supermassive black hole at its heart equal in mass to about 21 million suns. The discovery suggests that supermassive black holes may be far more common than previously thought.
A supermassive black hole millions to billions of times the mass of the sun lies at the heart of nearly every large galaxy like the Milky Way. These monstrously huge black holes have existed since the infancy of the universe, some 800 million years or so after the Big Bang. Scientists are uncertain whether dwarf galaxies might also harbor supermassive black holes. [Watch a Space.com video about the new dwarf galaxy finding]
"Dwarf galaxies usually refer to any galaxy less than roughly one-fiftieth the brightness of the Milky Way," said lead study author Anil Seth, an astronomer at the University of Utah in Salt Lake City. These galaxies span only several hundreds to thousands of light-years across, much smaller than the Milky Way's 100,000-light-year diameter, and they "are much more abundant than galaxies like the Milky Way," Seth said.
The researchers investigated a rarer kind of dwarf galaxy known as an ultra-compact dwarf galaxy; such galaxies are among the densest collections of stars in the universe. "These are found primarily in galaxy clusters, the cities of the universe," Seth told Space.com.
This image shows a huge galaxy, M60, with the small dwarf galaxy that is expected to eventually merge with it.
Credit: NASA/Space Telescope Science Institute/European Space Agency
Credit: NASA/Space Telescope Science Institute/European Space Agency
Now, Seth and his colleagues have discovered that an ultra-compact dwarf galaxy may possess a supermassive black hole, which would make it the smallest galaxy known to contain such a giant.
The astronomers investigated M60-UCD1, the brightest ultra-compact dwarf galaxy currently known, using the Gemini North 8-meter optical-and-infrared telescope on Hawaii's Mauna Kea volcano and NASA's Hubble Space Telescope. M60-UCD1 lies about 54 million light-years away from Earth. The dwarf galaxy orbits M60, one of the largest galaxies near the Milky Way, at a distance of only about 22,000 light-years from the larger galaxy's center, "closer than the sun is to the center of the Milky Way," Seth said.
The scientists calculated the size of the supermassive black hole that may lurk inside M60-UCD1 by analyzing the motions of the stars in that galaxy, which helped the researchers deduce the amount of mass needed to exert the gravitational field seen pulling on those stars. For instance, the stars at the center of M60-UCD1 zip at speeds of about 230,000 mph (370,000 km/h), much faster than stars would be expected to move in the absence of such a black hole.
This illustration depicts the supermassive black hole located at the center of the very dense galaxy M60-UCD1. It may weigh 21 million times the mass of our sun.
Credit: NASA, ESA, D. Coe, G. Bacon (STScI)
Credit: NASA, ESA, D. Coe, G. Bacon (STScI)
The supermassive black hole at the core of the Milky Way has a mass of about 4 million suns, taking up less than 0.01 percent of the galaxy's estimated total mass, which is about 50 billion suns. In comparison, the supermassive black hole that may lie in the core of M60-UCD1 appears five times larger than the one in the Milky Way, and also seems to make up about 15 percent of the dwarf galaxy's mass, which is about 140 million suns.
"That is pretty amazing, given that the Milky Way is 500 times larger and more than 1,000 times heavier than the dwarf galaxy M60-UCD1," Seth said in a statement.
Astronomers have debated the nature of ultra-compact dwarf galaxies for years — whether they were extremely massive clusters of stars that were all born together, or whether they were the centers or nuclei of large galaxies that had their outer layers stripped away during collisions with other galaxies. These new findings hint that ultra-compact dwarf galaxies are the stripped nuclei of larger galaxies, because star clusters do not host supermassive black holes.
The researchers suggest M60-UCD1 was once a very large galaxy, with maybe 10 billion stars, "but then it passed very close to the center of an even larger galaxy, M60, and in that process, all the stars and dark matter in the outer part of the galaxy got torn away and became part of M60," Seth said in a statement. "That was maybe as much as 10 billion years ago. We don't know."
The Gemini North Observatory in Hawaii shoots a laser beam into the sky as an "artificial star."
Credit: Gemini Observatory/Association of Universities for Research in Astronomy
Credit: Gemini Observatory/Association of Universities for Research in Astronomy
Eventually, M60-UCD1 "may merge with the center of M60, which has a monster black hole in it, with 4.5 billion solar masses — more than 1,000 times bigger than the supermassive black hole in our galaxy," Seth said in a statement. "When that happens, the black hole we found in M60-UCD1 will merge with that monster black hole."
The astronomers suggest the way stars move in many other ultra-compact dwarf galaxies hints that they may host supermassive black holes, as well. All in all, the scientists suggest that ultra-compact dwarf galaxies could double the number of supermassive black holes known in the nearby regions of the universe. The researchers are participating in ongoing projects that may provide conclusive evidence for supermassive black holes in four other ultra-compact dwarfs.
Black holes may have grown incredibly rapidly in the newborn universe, perhaps helping explain why they appear so early in cosmic history, researchers say.
Black holes possess gravitational pulls so powerful that not even light can escape their clutches. They are generally believed to form after massive stars die in gargantuan explosions known as supernovas, which crush the remaining cores into incredibly dense objects.
Supermassive black holes millions to billions of times the mass of the sun occur at the center of most, if not all, galaxies. Such monstrously large black holes have existed since the infancy of the universe, some 800 million years or so after the Big Bang. However, it remains a mystery how these giants could have grown so big in the relatively short amount of time they had to form.
In modern black holes, features called accretion disks limit the speed of growth. These disks of gas and dust that swirl into black holes can prevent black holes from growing rapidly in two different ways, researchers say. First, as matter in an accretion disk gets close to a black hole, traffic jams occur that slow down any other infalling material. Second, as matter collides within these traffic jams, it heats up, generating energetic radiation that drives gas and dust away from the black hole.
"Black holes don't actively suck in matter — they are not like vacuum cleaners," said lead study author Tal Alexander, an astrophysicist at the Weizmann Institute of Science in Rehovot, Israel.
"A star or a gas stream can be on a stable orbit around a black hole, exactly as the Earth revolves around the sun, without falling into it," Alexander told Space.com. "It is actually quite a challenge to think of efficient ways to drive gas into the black hole at a high enough rate that can lead to rapid growth."
Alexander and his colleague Priyamvada Natarajan may have found a way in which early black holes could have grown to supermassive proportions — in part, by operating without the restrictions of accretion disks. The pair detailed their findings online today (Aug. 7) in the journal Science.
The scientists began with a model of a black hole 10 times the mass of the sun embedded in a cluster of thousands of stars. They fed the simulated black hole continuous flows of dense, cold, opaque gas.
"The early universe was much smaller and hence denser on average than it is today," Alexander said.
This cold, dense gas would have obscured a substantial amount of the energetic radiation given off by matter falling into the black hole. In addition, the gravitational pull of the many stars around the black hole "causes it to zigzag randomly, and this erratic motion prevents the formation of a slowly draining accretion disk," Alexander said. This means that matter falls into the black hole from all sides instead of getting forced into a disk around the black hole, from which it would swirl in far more slowly.
The "supra-exponential growth" observed in the model black hole suggests that a black hole 10 times the mass of the sun could have grown to more than 10 billion times the mass of the sun by just 1 billion years after the Big Bang, researchers said.
"This theoretical result shows a plausible route to the formation ofsupermassive black holes very soon after the Big Bang," Alexander said.
Future research could examine whether supra-exponential growth of black holes could occur in modern times as well. The high-density and high-mass cold flows seen in the ancient universe may exist "for short times in unstable, dense, star-forming clusters, or in dense accretion disks around already-existing supermassive black holes," Alexander said.
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