Indian space agency Tata Institute of Fundamental Research (TIFR) reported a black hole within the Milky Way is spinning so fast it is changing the face of space around it. The black hole, found in the binary star system called 4U 1630-47, was spotted thanks to the X-rays it was emitting by India's AstroSat and Nasa's Chandra X-Ray Observatory. Albert Einstein theorised in his famous theory of relativity that nothing can move faster than the speed of light – 670 million miles an hour (299,792,458 metres per second). However, the black hole, which was originally observed in 2016, is close to breaking this universal limit as it spirals at 90 percent of this speed.

The rapid movement of the black hole is causing gas, dust and other celestial debris to be sucked in by the entity at a more rapid pace than usual. However, this also meant it was spewing more materials out in the form of X-rays which made it easier to observed. Speaking to the Hindustan Times, Sudip Bhattacharyya of TIFR, and principal investigator of Astrosat's Soft X-ray Telescope (SXT), said of the results which will be published in next month’s Astrophysical Journal: “As black holes get created, mass and spin rate are two properties that characterise them. “Mass can be measured more easily as it has a long-range effect because of gravity as the black hole gets created.”

Only four black holes have been found to spin at such an extreme pace. The first was discovered in 2008 using NASA’s Chandra X-ray Observatory. Lead author Rodrigo Nemmen said at the time: "We think these monster black holes are spinning close to the limit set by Einstein's theory of relativity, which means that they can drag material around them at close to the speed of light. </s> A massive black hole is spinning so fast that it tests the limits of Einstein's theory of relativity and may rotate space around itself, according to a joint study by India's AstroSat and NASA's Chandra X-Ray Observatory.

The black hole in question is roughly 10 times the mass of the Sun and one of only five with an accurately measured spin rate this fast, close to the speed of light.

India's first dedicated astronomy satellite, Astrosat, launched back in 2015, observed the frenetic pace of the black hole, with findings later confirmed by NASA’s Chandra X-Ray Observatory.

Scientists measure black holes in terms of their mass or their spin rate, which ranks on a scale of 0 to 1. This black hole, in the binary star system 4U 1630-47, has been clocked at a phenomenal rate of 0.9 - in other words, very close to the limit set by Einstein’s theory of relativity.

The incredible void might also provide the key to understanding how galaxies form.

Gas, dust and other mass from the 4U 1630-47 system’s star gets torn away and forms a disk around the black hole, reaching temperatures of over 10 million degrees Celsius and blasting out x-rays monitored and measured by the Chandra Observatory. The overall system generates more than 10,000 times the power emitted by our sun.

Think your friends would be interested? Share this story! </s> One of the fastest black holes ever seen is spinning so fast it is moving space itself.

X-rays from a star system within the Milky Way revealed the presence of the black hole.

Analysis of these high-energy waves revealed the black hole has a mass ten times greater than that of our sun and is rotating close to the speed of light.

There have only ever been four other black holes found to be spinning at such a speed.

This intergalactic speed limit of 670 million miles an hour (299,792,458 metres per second) was first proposed by Albert Einstein via his famed theory of relativity.

X-rays from the distant binary star system 4U 1630-47 revealed the black hole's existence when they were detected by India's AstroSat and Nasa's Chandra X-Ray Observatory.

These observations, first taken in 2016, have revealed that the black hole is moving at 90 per cent of the maximum spin rate.

Rapid movement caused gas, dust and other celestial debris to be absorbed by the black hole's enormous gravity.

Analysis from the researchers discovered this was happening as a result of the black hole spinning fast enough to suck up matter in the nearby vicinity.

'As black holes get created, mass and spin rate are two properties that characterise them,' Sudip Bhattacharyya of Tata Institute of Fundamental Research, and principal investigator of Astrosat's Soft X-ray Telescope (SXT), told Hindustan Times.

'Mass can be measured more easily as it has a long-range effect because of gravity as the black hole gets created,' he added.

This black hole is also believed to be one of only 20 in the Milky Way.

The speed of the black hole has been confirmed by both the US and India, who collaborate don the research project which is due to be published in The Astrophysical Journal. </s> Black holes, while fascinating, are hardly a new discovery - but a black hole spinning at one of the highest speeds ever, according to the Hindustan Times, is a completely different story - especially when there have only ever been four others like it.

In 2016, India's first dedicated astronomy satellite, the AstroSat, spotted a black hole in the binary star system called 4U 1630-47, which is bursting out X-rays that astronomers found unusual.

Those X-rays were caused by gas and dust falling into the black hole, which is about 10 times the mass of the Sun, and they revealed to researchers that the object is spinning very, very rapidly.

In fact, according to NASA this particular black hole is spinning very close to the limit set by Albert Einstein's theory of relativity, according to Rodrigo Nemmen, the lead author on the research paper. That means it is spinning close to the speed of light.

Currently, scientists only have two ways of measuring black holes - either by their mass or by their spin rate. A spin rate can be anywhere between 0 and 1: this black hole was spinning at the rate of 0.9.

Einstein's theory further implies that if a black hole is spinning that fast, then it is capable of making space itself rotate.

In fact, if the conditions around black holes are hypothesised to be correct, then the high spin rate coupled with the gaseous elements entering the black hole and high temperatures, could be the key to understanding how galaxies are formed.

Including the black hole discovered by the AstroSat, there are only five black holes that have accurately measured high spin rates. Even if you're not taking spin rates into account, this black hole is one of only 20 others that have been spotted in the Milky Way galaxy.

The Indian Space Research Organisation's (ISRO) AstroSat along with the National Aeronautics and Space Administration's (NASA) Chandra X-Ray Observatory have confirmed the speed of the spinning black hole.

The study was conducted by researchers from multiple institutions led by the Tata Institute of Fundamental Research (TIFR) and has been accepted for publication in The Astrophysical Journal.

This article was originally published by Business Insider. </s> An international team of astronomers has confirmed the discovery of a black hole which spins very close to the limit set by Albert Einstein's theory of relativity, which means that it spins close to the speed of light, according to Business Insider.

The black hole was first tracked in the binary stellar system 4U 1630−47 in 2016 by the Indian Space Research Organization (ISRO)'s AstroSat, in coordination with the National Aeronautics and Space Administration (NASA)'s Chandra X-ray Observatory.

READ MORE: Astronomers Capture Black Hole Devouring Cosmic Doughnut for First Time

Researchers then used the X-ray data from AstroSat and Chandra to calculate that the black hole is spinning a rate of 0.9, which is close to the celestial object's maximum possible rate of 1.

In this context, Business Insider quoted Rodrigo Nemmen, one of the lead authors of the research, as saying that Einstein's theory of relativity "further implies that if a black hole is spinning that fast, then it is capable of making space itself rotate."

READ MORE: Astronomers Discover Monster Black Hole the Size of 20 Billion Suns

Astronomers said that the discovery of the black hole, which is only one of five having an accurately measured high spin rate, may contribute greatly to uncovering the truth about the origin of the Universe. </s> India's first astronomy dedicated satellite, AstroSat, together with NASA's Chandra X-ray Observatory, helped scientists find an 'extremely exotic' black hole spinning close to the maximum possible rate. The black hole exists in the binary star system 4U 1630-47 and obviously cannot be directly seen, because nothing, not even light, can escape from a region around it, thus justifying the name of the object.

The gravity of such a collapsing core is so strong that its entire mass is crushed into a point, according to the research accepted for publication in The Astrophysical Journal.

Mass and spin classify a black hole

Relatively smaller black holes are exotic end states of massive stellar cores, said astronomers led by the Tata Institute of Fundamental Research (TIFR) in Mumbai.

Surprisingly, astronomical black holes are the simplest known objects in the universe, because they can be fully characterised by only two properties, mass and spin rate.

Therefore, measurements of these two properties are uniquely important to probe some extreme aspects of the universe and the fundamental physics related to them, researchers said.

"The scientific measurement of the spin rate of the black hole, an extremely exotic but the simplest object of the universe, comes out to be close to the maximum possible value," Sudip Bhattacharyya, the Associate Professor at TIFR and the Principal Investigator of the AstroSat Soft X-ray Telescope (SXT), told PTI.

"This is generally very important to probe some extreme aspects of the universe and the fundamental physics (for example, the theory of gravitation) related to them," said Bhattacharyya.

"Such measurements, especially of the spin rate, are very difficult to make, and can be done only by high-quality X-ray observations in the correct state of the binary stellar system, in which the black hole is gobbling matter from its companion star," said Mayukh Pahari, who started this work at TIFR, before joining the University of Southampton in the UK.

Also read | India launches its first satellite dedicated only for astronomy: All about it

Indian satellite AstroSat and its Soft X-ray Telescope (SXT)

AstroSat was launched in 2015 by the Indian Space Research Organisation (ISRO). It is the first dedicated astronomy satellite of India, and the SXT aboard AstroSat is the first Indian X-ray telescope.

"The SXT and the Large Area X-ray Proportional Counter (LAXPC) aboard the first dedicated Indian astronomy satellite AstroSat played a key role to measure the black hole spin rate, which was consistent with results from our contemporaneous Chandra satellite data," Mr Bhattacharyya added.

"From this first joint AstroSat-Chandra study of a black hole, that may lead to further such co-operations, we have found that the black hole in 4U 1630-47 spins very rapidly, with a rate not much less than the maximum possible rate, which makes it even more exotic," added Professor AR Rao of TIFR.

"In fact, apart from Japan, I believe, India is the first Asian country to build an X-ray Telescope (for example, China could not build such a telescope till now)," Bhattacharyya said.

He noted that this "first cooperation of India and US using AstroSat and Chandra satellites regarding black hole studies should open up ways for future such collaborations."

More about AstroSat

India's first astronomy dedicated satellite AstroSat is capable of making an observation in the ultraviolet, optical, low and high energy X-Rays wavebands at the same time. It comprises of five scientific instruments:

The UV Imaging Telescope

The Scanning Sky Monitor

The Cadmium-Zinc-Telluride Imager

The Soft X-ray Telescope, and

Three identical Large Area Xenon Proportional Counters

Tata Institute of Fundamental Research, Indian Institute of Astrophysics, Inter-University Centre for Astronomy and Astrophysics, and Raman Research Institute joined ISRO in the development of payload.

Two of the payloads were made in collaboration with Canadian Space Agency (CSA) and University of Leicester, UK.

Also read | 'Vampire' star caught feeding on bigger star by Astrosat

Interested in General Knowledge and Current Affairs? Click here to stay informed and know what is happening around the world with our G.K. and Current Affairs section.

To get more updates on Current Affairs, send in your query by mail to education.intoday@gmail.com </s> Black holes occur when a massive star dies and collapses with enough gravity that nothing, not even light, can escape from it.

Black holes can absorb the surrounding mass and grow – eventually turning into supermassive black holes that can lie at the center of galaxies.

Now a team of Indian astronomers believe they’ve found a black hole spinning at a rate that’s close to the maximum possible speed it can go.

They first noticed it from X-rays that were picked up by India’s first ever dedicated astronomy satellite, called AstroSat.

Black holes are characterised by spin and mass(Getty)

The X-rays were coming from a binary star system called 4U 1630-47 that contains the black hole, which is about 10 times the mass of our sun. As gas, dust and other matter were absorbed by the spinning black hole, the research team figured out it was spinning fast enough to suck up all the space around it.

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‘As black holes get created, mass and spin rate are two properties that characterise them,’ Sudip Bhattacharyya of TIFR, and principal investigator of Astrosat’s Soft X-ray Telescope (SXT), told Hindustan Times.

‘Mass can be measured more easily as it has a long-range effect because of gravity as the black hole gets created,’ he added.

According to Einstein’s theory of relativity, a rapidly spinning black hole makes space itself rotate.

Caption: Black hole. Computer artwork representing a black hole against a starfield. (Getty)

This effect, coupled with gas spiraling toward the black hole, can produce a rotating, tightly wound vertical tower of magnetic field that flings a large fraction of the inflowing gas away from the vicinity of the black hole in an energetic, high-speed jet.

And the team believe this particular black hole is spinning almost as fast as it’s possible to do so.

Including the black hole discovered by the AstroSat, there are only five black holes that have accurately measured high spin rates.

Even if you’re not taking spin rates into account, this black hole is one of only 20 others that have been spotted in the Milky Way galaxy.

Caption: This artwork shows a star being distorted by its close passage to a supermassive black hole at the centre of a galaxy. (Getty)

‘Measurements, especially of the spin rate are very difficult to make, and can be done only by high-quality X-ray observations in the correct state of the binary stellar system, in which the black hole is a gobbling matter from its companion star,’ said the lead author Mayukh Pahari.

The research, which was a joint effort between the USA and India, has been accepted for publication in The Astrophysical Journal. </s> A giant black hole ripped apart a star and then gorged on its remains for about a decade, according to astronomers. This is more than ten times longer than any observed episode of a star’s death by black hole.

Researchers made this discovery using data from NASA’s Chandra X-ray Observatory and Swift satellite as well as ESA’s XMM-Newton. They published their findings February 6 in Nature Astronomy.

The trio of orbiting X-ray telescopes found evidence for a “tidal disruption event” (TDE), wherein the tidal forces due to the intense gravity from a black hole can destroy an object – such as a star – that wanders too close. During a TDE, some of the stellar debris is flung outward at high speeds, while the rest falls toward the black hole. As it travels inwards to be ingested by the black hole, the material heats up to millions of degrees and generates a distinct x-ray flare.

“We have witnessed a star’s spectacular and prolonged demise,” said Dacheng Lin from the University of New Hampshire in Durham, who led the study. “Dozens of tidal disruption events have been detected since the 1990s, but none that remained bright for nearly as long as this one.”

According to coauthor Enrico Ramirez-Ruiz, professor and chair of astronomy and astrophysics at UC Santa Cruz, the observations of this TDE with a long-lasting bright phase fit the theoretical predications made in a 2015 paper he wrote with a former graduate student, coauthor James Guillochon, now at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.

“We correctly predicted in advance of observations that some TDEs would be discovered with long-lived light curves,” Ramirez-Ruiz said. “The pieces of the star have to make an accretion disk promptly in order for the material to be digested by the black hole. With a lower mass black hole, stars can get disrupted farther away from the event horizon, and as a result we expect circularization and accretion to be slow.”

The extraordinary long bright phase of this event spanning over ten years means that a large amount of mass had to be digested by the black hole. The theoretical model supports either the complete digestion of a star with twice the mass of the sun, or the partial disruption of a much more massive star, Ramirez-Ruiz said, adding that he favors the full disruption of a lower mass star.

The X-ray source containing this force-fed black hole, known by its abbreviated name of XJ1500+0154, is located in a small galaxy about 1.8 billion light years from Earth.

The source was not detected in a Chandra observation on April 2nd, 2005, but was detected in an XMM-Newton observation on July 23rd, 2005, and reached peak brightness in a Chandra observation on June 5, 2008. These observations show that the source became at least 100 times brighter in x-rays. Since then, Chandra, Swift, and XMM-Newton have observed it multiple times.

The sharp x-ray vision of Chandra data shows that XJ1500+0154 is located at the center of its host galaxy, the expected location for a supermassive black hole. The x-ray data also indicate that radiation from material surrounding this black hole has consistently surpassed the so-called Eddington limit, defined by a balance between the outward pressure of radiation from the hot gas and the inward pull of the gravity of the black hole.

“For most of the time we’ve been looking at this object, it has been growing rapidly,” Guillochon said. “This tells us something unusual—like a star twice as heavy as our Sun—is being fed into the black hole.”

This TDE may help answer the question as to how supermassive black holes in the early universe grow. If supermassive black holes can grow from TDEs or other means faster than the Eddington limit, this could explain how supermassive black holes were able to reach masses about a billion times higher than the sun when the universe was only about a billion years old.

“This event shows that black holes really can grow at extraordinarily high rates,” said co-author Stefanie Komossa of QianNan Normal University for Nationalities in Duyun City, China. “This may help understand how precocious black holes came to be.”

Based on the modeling by the researchers, the black hole’s feeding supply should be significantly reduced in the next decade. This would result in XJ1500+0154 fading in x-ray brightness over the next several years.

NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for NASA’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra’s science and flight operations. </s> Astronomers conduct successful test of Einstein’s general theory of relativity near supermassive black hole.

The massive black hole at the heart of the Milky Way is an ideal cosmic laboratory for all kinds of physical tests. Its extremely strong gravitational field influences the surrounding area and has an impact on the motion of stars passing by. Scientists at the Max Planck Institute for Extraterrestrial Physics (MPE) have now observed an effect that had been predicted by Albert Einstein with his general theory of relativity more than 100 years ago. The discovery of this gravitational redshift represents the climax of a 26-year-long observation campaign using telescopes of the European Southern Observatory (ESO) in Chile.

The closest supermassive black hole to the Earth lies 26,000 light-years away at the centre of the Milky Way. This gravitational trap, which has a mass four million times that of our Sun, is surrounded by a small group of stars orbiting around it at high speed. This region, with the strongest gravitational field in our galaxy, is the perfect place to explore gravitational physics, and particularly to test Einstein’s general theory of relativity.



 This artist’s impression video shows the path of the star S2 as it passes very close to the supermassive black hole at the centre of the Milky Way. As it gets close to the black hole the very strong gravitational field causes the colour of the star to shift slightly to the red, an effect of Einstein’s general theory of relativity. In this graphic the colour effect, speed and size of the objects have been exaggerated for clarity.

In order to observe the galactic centre, the astronomers use sensitive instruments such as Gravity, Sinfoni and Naco. All these belong to the ESO’s Very Large Telescope, were constructed under the leadership of the Max Planck Institute for Extraterrestrial Physics (MPE), and scrutinise the sky in an infrared light. Now, researchers have turned their attention to a star called S2 and followed it on its orbit around the black hole, to which it came particularly close a few weeks ago.

The shortest distance between S2 and the black hole, on 19 May, was approximately 14 billion kilometres. Here, the star moved at a speed in excess of 25 million kilometres per hour – almost three percent of the speed of light. It takes about 15 years to complete its full orbit.

The scientists compared the position and velocity measurements from Gravity and Sinfoni, along with the measurements taken during previous observations of S2, with the predictions of Newtonian gravitational physics, the general theory of relativity and other theories of gravity. In fact, the new results are inconsistent with Newtonian predictions, although they are in excellent agreement with the predictions of the general theory of relativity.

“This is the second time that we have observed the close passage of S2 around the black hole in our galactic centre. But this time, because of much improved instrumentation, we were able to observe the star with unprecedented detail resolution,” explains Richard Genzel, Director of the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching near Munich, and head of the international team of scientists.



 This time-lapse view shows images from the GRAVITY instrument on ESO’s Very Large Telescope as it tracks the progress of the star S2 as it made a close passage past the black hole at the centre of the Milky Way in May 2018.

The new measurements clearly reveal an effect called gravitational redshift. Light from the star is stretched to longer wavelengths by the very strong gravitational field of the black hole, making it appear red. And this change in the wavelength agrees precisely with that predicted by Einstein’s theory of general relativity. This is the first time that the researchers have observed this deviation from the predictions of the simpler Newtonian theory of gravity in the motion of a star around a supermassive black hole.

The team used the Sinfoni instrument to measure the velocity of S2 relative to Earth. Astronomers use Gravity to make extraordinarily precise measurements of the changing position of S2, and thus also of the shape of its orbit. In connection with what is known as interferometry, in which the light of several telescopes is merged and overlaid, Gravity creates extremely sharp images. On these images, the motion of the star can even be followed from night to night as it passes close to the black hole – 26,000 light-years from Earth.

“Our first observations of S2 with Gravity, about two years ago, already showed that with the galactic centre, we have the ideal black hole laboratory,” says Frank Eisenhauer from the Max Planck Institute in Garching, Principal Investigator of Gravity and Sinfoni. During the close passage, even the faint glow around the black hole could be detected on most of the images. “In this way, we could follow the star on its orbit to an extremely high degree of precision, and could ultimately provide evidence of the gravitational redshift in the spectrum of S2.”



 This animation shows the orbit of the star S2 around the supermassive black hole at the heart of the Milky Way. At its closest approach, which occurred most recently in May 2018, the star is traveling at nearly 3% of the speed of light and is an ideal test object for studying very strong gravitational fields and testing Einstein’s general theory of relativity.

More than 100 years after he published his paper setting out the equations of general relativity, Einstein has been proved right once more – in a much more extreme laboratory than he could have possibly imagined. “In the strong gravitational field around the black hole, we generally expect to see relativistic effects – but only when we are able to conduct sufficiently precise observations”, says Stefan Gillessen from the Max Planck Institute for Extraterrestrial Physics. “For this reason, we had to push the technology to the limits.”

Further measurements will follow, and are already expected to reveal another relativistic effect soon – a small rotation of the star’s orbit known as Schwarzschild precession – as S2 moves away from the black hole.

Paper: Detection of the Gravitational Redshift in the Orbit of the Star S2 near the Galactic Centre Massive Black Hole
NASA's Chandra X-ray Observatory confirms earlier observations by Indian Space Research Organisation's Astrosat space observatory of a rotating black hole in the binary star system 4U1630-47, which is spinning close to the speed of light, one of the fastest ever observed.