Watch a black hole tear a star to bits in epic new animation

The awesome spectacle of a black hole ripping a star to shreds can be seen in this striking new visualization from the Deutsches Elektronen-Synchrotron (DESY), a particle accelerator lab in Hamburg, Germany. Such events are known as stellar tidal disruptors, and they are fairly rare, occurring just once every 10,000 years in a typical galaxy, according to NASA. Stars are typically flung toward a ravenous black hole after interacting gravitationally with another star or massive object, only to become stretched and devoured should they come too close to the black hole's maw in a process called spaghettification. Gravitational tidal forces, similar to the ones that cause the moon to raise tides on Earth, are responsible for most of the destruction. At first, the star's outer atmospheric layers will get pulled toward the black hole, spinning around its edge like water going down a drain and forming what's known as an accretion disk, as the video depicts. Surprisingly, the black hole only consumes about 1% of a star's mass, according to NASA. The majority will actually get catapulted back out into space in the form of enormous jets of energy and matter that shoot from the black hole's central region. These jets can sometimes light up the cosmos, allowing astronomers on Earth to catch glimpses of distant black holes, which are otherwise mostly invisible. Tiny, ghostly particles called neutrinos will also be flung from the black hole, occasionally giving researchers insights into processes occurring during the consumption event.

Some of the star's material does fall past the event horizon, the point after which nothing, including light, can escape. The visualization shows some of the strange optical effects that the event horizon produces, such as bending light so much that regions at the back of the accretion disk can be seen from its front.

Witnessing how swiftly the black hole dismembers and dispatches the star is an excellent reminder that no one should want to get anywhere near such a powerful object any time soon.

Black hole dubbed 'the Unicorn' may be galaxy's smallest one

Scientists have discovered what may be the smallest-known black hole in the Milky Way galaxy and the closest to our solar system - an object so curious that they nicknamed it 'the Unicorn.' The researchers said the black hole is roughly three times the mass of our sun, testing the lower limits of size for these extraordinarily dense objects that possess gravitational pulls so strong not even light can escape. A luminous star called a red giant orbits with the black hole in a so-called binary star system named V723 Mon.The black hole is located about 1,500 light years - the distance light travels in a year, 5.9 trillion miles (9.5 trillion km) - from Earth. While it may be the closest one to us, it is still far away. By way of comparison, the closest star to our solar system, Proxima Centauri, is 4 light years away. Black holes like this one form when massive stars die and their cores collapse. "We nicknamed this black hole 'the Unicorn' partly because V723 Mon is in the Monoceros constellation - which translates to unicorn - and partly because it is a very unique system" in terms of the black hole's mass and relative closeness to Earth, said Ohio State University astronomy doctoral student Tharindu Jayasinghe, lead author of the study published this week in the journal Monthly Notices of the Royal Astronomical Society.

There are three categories of black holes. The smallest, like 'the Unicorn,' are so-called stellar mass black holes formed by the gravitational collapse of a single star. There are gargantuan 'supermassive' black holes like the one at our galaxy's center, 26,000 light years from Earth, which is four million times the sun's mass. A few intermediate-mass black holes also have been found with masses somewhere in between.

"It is clear that nature makes black holes of a wide range of masses. But a three-solar-mass black hole is a big surprise. There are no very good models for how to make such a black hole, but I am sure people will work on that more now," said Ohio State University astronomy professor and study co-author Kris Stanek.

'The Unicorn' falls into what the researchers called a "mass gap" between the largest-known neutron stars - objects similarly formed by a large star's collapse - at around 2.2 times the mass of our sun and what previously had been considered the smallest black holes at around five times the sun's mass.

"'The 'unicorn' is truly one of the smallest black holes possible," Jayasinghe said.

Its strong gravity alters the shape of its companion star in a phenomenon known as tidal distortion, making it elongated rather than spherical and causing its light to change as it moves along its orbital path. It was these effects on the companion star, observed using Earth-based and orbiting telescopes, that indicated the black hole's presence.

"Black holes are electromagnetically dark, and so they are difficult to find," Jayasinghe said.

Unlike some other black holes orbiting with a star, this one was not observed to be drawing material from its companion, which is 173 times more luminous than our sun.

The only smaller potential black hole is one with a mass 2.6 times that of our sun that was spotted in another galaxy, Jayasinghe said.

Black holes could be dark stars with 'Planck hearts'

Black holes, those gravitational monsters so named because no light can escape their clutches, are by far the most mysterious objects in the universe. But a new theory proposes that black holes may not be black at all. According to a new study, these black holes may instead be dark stars home to exotic physics at their core. This mysterious new physics may cause these dark stars to emit a strange type of radiation; that radiation could in turn explain all the mysterious dark matter in the universe, which tugs on everything but emits no light. Thanks to Einstein’s theory of general relativity, which describes how matter warps space-time, we know that some massive stars can collapse in on themselves to such a degree that they just keep collapsing, shrinking down into an infinitely tiny point — a singularity. Once the singularity forms, it surrounds itself with an event horizon. This is the ultimate one-way street in the universe. At the event horizon, the gravitational pull of the black hole is so strong that in order to leave, you’d have to travel faster than light does. Since traveling faster than the speed of light is utterly forbidden, anything that crosses the threshold is doomed forever.

'Black holes' with Planck hearts would lack a true event horizon (like the one illustrated in this image). (Image credit: AleksandrMorrisovich/Shutterstock)

Hence, a black hole.

These simple yet surprising statements have held up to decades of observations. Astronomers have watched as the atmosphere of a star gets sucked into a black hole. They've seen stars orbit black holes. Physicists on Earth have heard the gravitational waves emitted when black holes collide. We’ve even taken a picture of a black hole’s "shadow" — the hole it carves out from the glow of surrounding gas.

And yet, mysteries remain at the very heart of black hole science. The very property that defines a black hole — the singularity — seems to be physically impossible, because matter can’t actually collapse down to an infinitely tiny point.

Planck engines

That means the current understanding of black holes will eventually need to be updated or replaced with something else that can explain what's at the center of a black hole.

But that doesn’t stop physicists from trying.

One theory of black hole singularities replaces those infinitely tiny points of infinitely compressed matter with something much more palatable: an incredibly tiny point of incredibly compressed matter. This is called a Planck core, because the idea theorizes that the matter inside a black hole is compressed all the way down to the smallest possible scale, the Planck length, which is 1.6 * 10^ minus 35 meters.

That's … small.

With a Planck core, which wouldn’t be a singularity, a black hole would no longer host an event horizon — there would be no place where the gravitational pull exceeds the speed of light. But to outside observers, the gravitational pull would be so strong that it would look and act like an event horizon. Only extremely sensitive observations, which we do not yet have the technology for, would be able to tell the difference.

Dark matter

Radical problems require radical solutions, and so replacing “singularity” with “Planck core” isn’t all that far-fetched, even though the theory is barely more than a faint sketch of an outline, one without the physics or mathematics to confidently describe that kind of environment. In other words, Planck cores are the physics equivalent of spitballing ideas.

That’s a useful thing to do, because singularities need some serious out-of-the-box thinking. And there might be some bonus side-effects. Like, for example, explaining the mystery of dark matter.

Dark matter makes up 85% of the mass of the universe, and yet it never interacts with light. We can only determine its existence through its gravitational effects on normal, luminous matter. For example, we can watch stars orbit the centers of the galaxies, and use their orbital speeds to calculate the total amount of mass in those galaxies.

In a new paper, submitted Feb. 15 to the preprint database arXiv, physicist Igor Nikitin at the Fraunhofer Institute for Scientific Algorithms and Computing in Germany takes the “radical singularity” idea and kicks it up a notch. According to the paper, Planck cores may emit particles (because there’s no event horizon, these black holes aren’t completely black). Those particles could be familiar or something new.

Perhaps, they would be some form of particle that could explain dark matter. If black holes are really Planck stars, Nikitin wrote, and they are constantly emitting a stream of dark matter, they could explain the motions of stars within galaxies.

his idea probably won't hold up to further scrutiny (there’s much more evidence for the existence of dark matter than just its effect on the motion of stars). But it’s a great example of how we need to come up with as many ideas as possible to explain black holes, because we never know what links there may be to other unsolved mysteries in the universe.

Star’s Destruction by Supermassive Black Hole Linked to Origin of Universe’s Highest-Energy Particles

A team of scientists has detected the presence of a high-energy neutrino—a particularly elusive particle—in the wake of a star’s destruction as it is consumed by a black hole. A team of scientists has detected the presence of a high-energy neutrino—a particularly elusive particle—in the wake of a star’s destruction as it is consumed by a black hole. This discovery, reported in the journal Nature Astronomy, sheds new light on the origins of Ultrahigh Energy Cosmic Rays—the highest energy particles in the Universe. The work, which included researchers from more than two dozen institutions, including New York University and Germany’s DESY research center, focused on neutrinos—subatomic particles that are produced on Earth only in powerful accelerators. Neutrinos—as well as the process of their creation—are hard to detect, making their discovery, along with that of Ultrahigh Energy Cosmic Rays (UHECRs), noteworthy. “The origin of cosmic high-energy neutrinos is unknown, primarily because they are notoriously hard to pin down,” explains Sjoert van Velzen, one of the paper’s lead authors and a postdoctoral fellow in NYU’s Department of Physics at the time of the discovery. “This result would be only the second time high-energy neutrinos have been traced back to their source.”

A view of the accretion disc around the supermassive black hole, with jet-like structures flowing away from the disc. The extreme mass of the black hole bends spacetime, allowing the far side of the accretion disc to be seen as an image above and below the black hole. Credit: DESY, Science Communication Lab

The following video, created by NASA, a research partner on the Nature Astronomy work, describes the findings in greater detail (video credit: NASA’s Goddard Space Flight Center).

Previous research by van Velzen, now at the Netherlands’ Leiden University, and NYU physicist Glennys Farrar, a co-author of the new Nature Astronomy paper, found some of the earliest evidence of black holes destroying stars in what are now known as Tidal Disruption Events (TDEs). These findings set the stage for determining if TDEs could be responsible for producing UHECRs.

The research reported in Nature Astronomy offered support for this conclusion.

Previously, the IceCube Neutrino Observatory, a National Science Foundation-backed detector located in the South Pole, reported the detection of a neutrino, whose path was later traced by the Zwicky Transient Facility at Caltech’s Palomar Observatory.

Specifically, its measurements showed a spatial coincidence of a high-energy neutrino and light emitted after a TDE—a star consumed by a black hole.

“This suggests these star shredding events are powerful enough to accelerate high-energy particles,” van Velzen explains.

“Discovering neutrinos associated with TDEs is a breakthrough in understanding the origin of the high-energy astrophysical neutrinos identified by the IceCube detector at the South Pole whose sources have so far been elusive,” adds Farrar, who proposed in a 2009 paper that UHECRs could be accelerated in TDEs. “The neutrino-TDE coincidence also sheds light on a decades old problem: the origin of Ultrahigh Energy Cosmic Rays.”

After the supermassive black hole tore the star apart, roughly half of the star debris was flung back out into space, while the remainder formed a glowing accretion disc around the black hole. The system shone brightly across many wavelengths and is thought to have produced energetic, jet-like outflows perpendicular to the accretion disc. A central, powerful engine near the accretion disc spewed out these fast subatomic particles. Credit: DESY, Science Communication Lab

Read Ghost Particle From Star Shredded by Black Hole Reveals Cosmic Particle Accelerator for more on this research.

Reference: “A tidal disruption event coincident with a high-energy neutrino” by Robert Stein, Sjoert van Velzen, Marek Kowalski, Anna Franckowiak, Suvi Gezari, James C. A. Miller-Jones, Sara Frederick, Itai Sfaradi, Michael F. Bietenholz, Assaf Horesh, Rob Fender, Simone Garrappa, Tomás Ahumada, Igor Andreoni, Justin Belicki, Eric C. Bellm, Markus Böttcher, Valery Brinnel, Rick Burruss, S. Bradley Cenko, Michael W. Coughlin, Virginia Cunningham, Andrew Drake, Glennys R. Farrar, Michael Feeney, Ryan J. Foley, Avishay Gal-Yam, V. Zach Golkhou, Ariel Goobar, Matthew J. Graham, Erica Hammerstein, George Helou, Tiara Hung, Mansi M. Kasliwal, Charles D. Kilpatrick, Albert K. H. Kong, Thomas Kupfer, Russ R. Laher, Ashish A. Mahabal, Frank J. Masci, Jannis Necker, Jakob Nordin, Daniel A. Perley, Mickael Rigault, Simeon Reusch, Hector Rodriguez, César Rojas-Bravo, Ben Rusholme, David L. Shupe, Leo P. Singer, Jesper Sollerman, Maayane T. Soumagnac, Daniel Stern, Kirsty Taggart, Jakob van Santen, Charlotte Ward, Patrick Woudt and Yuhan Yao, 22 February 2021, Nature Astronomy.
DOI: 10.1038/s41550-020-01295-8

The research was supported by grants from the National Science Foundation (CAREER grant 1454816, AAG grant 1616566, PIRE Grant 1545949, NSF grant AST-1518052)

Philosophy: What exactly is a black hole?

A black hole is conventionally thought of as an astronomical object that irrevocably consumes all matter and radiation which comes within its sphere of influence. Physically, a black hole is defined by the presence of a singularity, i.e., a region of space, bounded by an 'event horizon', within which the mass/energy density becomes infinite, and the normally well-behaved laws of physics no longer apply. However, as an article in the January issue of the journal Nature Astronomy demonstrates, a precise and agreed definition of this 'singular' state proves to be frustratingly elusive. Its author, Dr. Erik Curiel of the Munich Center for Mathematical Philosophy at Ludwig-Maximilians-Universitaet, summarizes the problem as follows: "The properties of black holes are the subject of investigations in a range of subdisciplines of physics - in optical physics, in quantum physics and of course in astrophysics. But each of these specialties approaches the problem with its own specific set of theoretical concepts." Erik Curiel studied Philosophy as well as Theoretical Physics at Harvard University and the University of Chicago, and the primary aim of his current DFG-funded research project is to develop a precise philosophical description of certain puzzling aspects of modern physics. "Phenomena such as black holes belong to a realm that is inaccessible to observation and experiment. Work based on the assumption that black holes exist therefore involves a level of speculation that is unusual even for the field of theoretical physics."

However, this difficulty is what makes the physical approach to the nature of black holes so interesting from the philosophical point of view. "The physical perspective on black holes is itself inextricably bound up with philosophical issues relating to ontological, metaphysical and methodological considerations," says Curiel.


"Surprising" and "eye-opening" insights

During the preparation of his philosophical analysis of the concept of black holes for Nature Astronomy, the author spoke to physicists involved in a wide range of research fields. In the course of these conversations, he was given quite different definitions of a black hole.

Importantly, however, each was used in a self-consistent way within the bounds of the specialist discipline concerned. Curiel himself describes these discussions as "surprising" and "eye-opening".

For astrophysicist Avi Loeb, "a black hole is the ultimate prison: once you check in, you can never get out." On the other hand, theoretical physicist Domenico Giulini regards it as "conceptually problematical to think of black holes as objects in space, things that can move and be pushed around."

Curiel's own take-home-message is that the very diversity of definitions of black holes is a positive sign, as it enables physicists to approach the phenomenon from a variety of physical perspectives. However, in order to make productive use of this diversity of viewpoints, it will be important to cultivate a greater awareness of the differences in emphasis between them.

Matter falling into a black hole at 30 percent of the speed of light

A UK team of astronomers report the first detection of matter falling into a black hole at 30% of the speed of light, located in the centre of the billion-light year distant galaxy PG211+143. The team, led by Professor Ken Pounds of the University of Leicester, used data from the European Space Agency's X-ray observatory XMM-Newton to observe the black hole. Their results appear in a new paper in Monthly Notices of the Royal Astronomical Society. Black holes are objects with such strong gravitational fields that not even light travels quickly enough to escape their grasp, hence the description 'black'. They are hugely important in astronomy because they offer the most efficient way of extracting energy from matter. As a direct result, gas in-fall - accretion - onto black holes must be powering the most energetic phenomena in the Universe. The centre of almost every galaxy - like our own Milky Way - contains a so-called supermassive black hole, with masses of millions to billions of times the mass of our Sun. With sufficient matter falling into the hole, these can become extremely luminous, and are seen as a quasar or active galactic nucleus (AGN). However black holes are so compact that gas is almost always rotating too much to fall in directly. Instead it orbits the hole, approaching gradually through an accretion disc - a sequence of circular orbits of decreasing size. As gas spirals inwards, it moves faster and faster and becomes hot and luminous, turning gravitational energy into the radiation that astronomers observe.

The orbit of the gas around the black hole is often assumed to be aligned with the rotation of the black hole, but there is no compelling reason for this to be the case. In fact, the reason we have summer and winter is that the Earth's daily rotation does not line up with its yearly orbit around the Sun.

Until now it has been unclear how misaligned rotation might affect the in-fall of gas. This is particularly relevant to the feeding of supermassive black holes since matter (interstellar gas clouds or even isolated stars) can fall in from any direction.

Using data from XMM-Newton, Prof. Pounds and his collaborators looked at X-ray spectra (where X-rays are dispersed by wavelength) from the galaxy PG211+143. This object lies more than one billion light years away in the direction of the constellation Coma Berenices, and is a Seyfert galaxy, characterised by a very bright AGN resulting from the presence of the massive black hole at its nucleus.

The researchers found the spectra to be strongly red-shifted, showing the observed matter to be falling into the black hole at the enormous speed of 30 per cent of the speed of light, or around 100,000 kilometres per second. The gas has almost no rotation around the hole, and is detected extremely close to it in astronomical terms, at a distance of only 20 times the hole's size (its event horizon, the boundary of the region where escape is no longer possible).

The observation agrees closely with recent theoretical work, also at Leicester and using the UK's Dirac supercomputer facility simulating the 'tearing' of misaligned accretion discs. This work has shown that rings of gas can break off and collide with each other, cancelling out their rotation and leaving gas to fall directly towards the black hole.

Prof. Pounds, from the University of Leicester's Department of Physics and Astronomy, said: "The galaxy we were observing with XMM-Newton has a 40 million solar mass black hole which is very bright and evidently well fed. Indeed some 15 years ago we detected a powerful wind indicating the hole was being over-fed. While such winds are now found in many active galaxies, PG1211+143 has now yielded another 'first', with the detection of matter plunging directly into the hole itself."

He continues: "We were able to follow an Earth-sized clump of matter for about a day, as it was pulled towards the black hole, accelerating to a third of the velocity of light before being swallowed up by the hole."

A further implication of the new research is that 'chaotic accretion' from misaligned discs is likely to be common for supermassive black holes. Such black holes would then spin quite slowly, being able to accept far more gas and grow their masses more rapidly than generally believed, providing an explanation for why black holes which formed in the early Universe quickly gained very large masses.

First Successful Test of General Relativity Near Supermassive Black Hole

Obscured by thick clouds of absorbing dust, the closest supermassive black hole to the Earth lies 26,000 light-years away at the centre of the Milky Way. This gravitational monster, which has a mass four million times that of the Sun, is surrounded by a small group of stars orbiting around it at high speed.This extreme environment - the strongest gravitational field in our galaxy - makes it the perfect place to explore gravitational physics, and particularly to test Einstein's general theory of relativity. New infrared observations from the exquisitely sensitive GRAVITY, SINFONI and NACO instruments, developed under the lead of the Max Planck Institute for Extraterrestrial Physics (MPE), have now allowed astronomers to follow one of these stars, called S2, as it passed very close to the black hole during May 2018. At the closest point this star was at a distance of less than 20 billion kilometres from the black hole and moving at a speed in excess of 25 million kilometres per hour - almost three percent of the speed of light.

The team compared the position and velocity measurements from GRAVITY and SINFONI respectively, along with previous observations of S2 using other instruments, with the predictions of Newtonian gravity, general relativity and other theories of gravity. The new results are inconsistent with Newtonian predictions and in excellent agreement with the predictions of general relativity.

These extremely precise measurements were made by an international team led by Reinhard Genzel (MPE) in Garching, Germany, in conjunction with collaborators around the world, at the Paris Observatory-PSL, the Universite Grenoble Alpes, CNRS, the Max Planck Institute for Astronomy, the University of Cologne, the Portuguese CENTRA (Centro de Astro?sica e Gravitacao) and ESO. The observations are the culmination of a 26-year series of ever-more-precise observations of the centre of the Milky Way using ESO instruments.

"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 resolution," explains Genzel. "We have been preparing intensely for this event over several years, as we wanted to make the most of this unique opportunity to observe general relativistic effects."

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. And the change in the wavelength of light from S2 agrees precisely with that predicted by Einstein's general theory of relativity. This is the first time that this deviation from the predictions of the simpler Newtonian theory of gravity has been observed in the motion of a star around a supermassive black hole.

The team used SINFONI to measure the velocity of S2 towards and away from Earth and the GRAVITY instrument in the VLT Interferometer (VLTI) to make extraordinarily precise measurements of the changing position of S2 in order to define the shape of its orbit. GRAVITY creates such sharp images that it can reveal the motion of the star 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 we would have the ideal black hole laboratory," adds Frank Eisenhauer (MPE), principal investigator of GRAVITY and the SINFONI spectrograph.

"During the close passage, we could even detect the faint glow around the black hole on most of the images, which allowed us to precisely follow the star on its orbit, ultimately leading to the detection of the gravitational redshift in the spectrum of S2."

More than one hundred 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!

"Due to the extremely strong gravitational field we expect to see the effects of general relativity - but only if we can look close enough," says Stefan Gillessen, "This is why we needed to push the technology. With SINFONI we can measure the radial velocity of stars very accurately and GRAVITY gives us extremely sharp images and accurate positions."

Continuing observations are expected to reveal another relativistic effect very soon - a small rotation of the star's orbit, known as Schwarzschild precession - as S2 moves away from the black hole.

Xavier Barcons, ESO's Director General, concludes: "ESO has worked with Reinhard Genzel and his team and collaborators in the ESO Member States for over a quarter of a century. It was a huge challenge to develop the uniquely powerful instruments needed to make these very delicate measurements and to deploy them at the VLT in Paranal. The discovery announced is the very exciting result of a remarkable partnership."

Ученые посвящают рождение новой черной дыры Стивену Хокингу

Один из телескопов сети MASTER Global Robotic Net telescopes (MSU), расположенный на острове Тенерифе (Испания, Канарские острова) помог ученым наблюдать гамма-всплеск, вызванный коллапсом одной звезды и формированием на ее месте черной дыры. Обычные телескопы неспособны осуществлять наведение на гамма-всплески с достаточно высокой скоростью, чтобы отследить изменения их яркости и получить информацию об их источниках. Гамма-всплески регистрируются космическими обсерваториями довольно часто – каждый день. Эти энергетические всплески сопровождают события столкновения нейтронных звезд или коллапса массивной звезды с превращением ее в нейтронную звезду, кварковую звезду или черную дыру. В случае каждого из перечисленных событий выделяются огромные количества энергии, и телескопы могут обнаружить гамма-всплески, даже если те происходят на расстояниях в миллионы и миллиарды световых лет от Земли. Гамма-всплески длятся от нескольких миллисекунд до десятков секунд и регистрируются в различных диапазонах.

«Главной задачей сети телескопов MASTER Global Robotic Net являются наблюдения раннего оптического излучения гамма-всплеска перед его затуханием. В оптическом диапазоне мы наблюдали всё это событие целиком, от начала до конца. Это редкий случай, который выдается лишь два или три раза в год, и, как правило, такие наблюдения всегда проводятся при помощи сети телескопов MASTER», - рассказал руководитель проекта MASTER Global Robotic Net и профессор кафедры физики Московского государственного университета Владимир Липунов.

Сообщение об этом открытии посвящено памяти Стивена Хокинга и опубликовано на веб-сайте Astronomer"s Telegram.

Бледнеть очень быстро квазары заставляет «голод»

Две группы астрономов попытались выяснить, что заставляет квазары – одни из ярчайших объектов во Вселенной – терять свою яркость буквально за несколько лет. Свои статьи ученые выложили на портале препринтов ArXiv. Квазары – сверхмассивные черные дыры в центрах галактик – заметны на очень больших расстояниях. Источником их свечения астрономы считают аккреционные диски – вращающиеся вокруг квазаров массы нагретого вещества. Предполагается, что такая структура должна светиться на протяжении миллионов лет и плавно угасать за десятки тысяч лет. Но в 2014 году американские астрономы обнаружили квазар, который стал практически невидим менее чем за десять лет. После этого открытия ученые стали предлагать различные объяснения: квазар могло закрыть от наблюдателей массивное облако пыли или, возможно, за квазар приняли вспышку звезды, подошедшей слишком близко к черной дыре. Однако позднее астрономы заметили еще несколько квазаров, чья яркость снижалась даже быстрее, чем у открытого в 2014 году.

Авторы двух недавних исследований полагают, что причина снижения яркости квазаров – уменьшение количества газа и пыли в их аккреционных дисках. Одна группа ученых, которой руководил астроном из Научно-технического университета Китая Чжэньфэн Шэн, изучила свет десяти быстро «побледневших» квазаров в оптическом и инфракрасном диапазонах. Так как видимое излучение аккреционного диска вызывает свечение окружающей материи в инфракрасном диапазоне, тот факт, что интенсивность видимого изучения снизилась раньше, чем инфракрасного, говорит о том, что причиной его стала именно нехватка вещества в аккреционном диске.

Авторы другой статьи, написанной под руководством астронома из Льежского университета Дамьена Хатсемекерса, исследовали свет одного быстро погасшего квазара. Они хотели проверить, могла ли яркость снизиться из-за прохождения облака пыли. Если это действительно так, то значительная часть света квазара должна была стать поляризованной. Однако доля поляризованного света до и после снижения яркости не различается, то есть оно вызвано внутренними процессами в квазаре, а не облаком пыли.

Ученые сделали прорыв в науке и вычислили вес черной дыры

Сотрудники южнокорейской обсерватории Eso нашли способ измерить вес гигантской черной дыры. Для этого они решили исследовать движение угарного газа. По данным ученых, наблюдая за движением молекулярного газа вокруг дыры, можно измерить силу тяготения и вычислить ее массу, сообщает «ПолитЭксперт». Так, по данным специалистов, вес черной дыры в галактике NGC 4526 равен массе 500 тысяч солнц.

Ранее астрономы не раз пытались измерить черные дыры, но использовали другие методы. Прежние способы расчета работали не со всеми галактиками.

Обнаружена черная дыра промежуточной массы в Стрельце

Международная команда астрономов под руководством ученых из Манчестерского университета, США, обнаружила свидетельства того, что в нашей галактике Млечный путь, в направлении созвездия Стрельца на небе скрывается черная дыра, представляющая собой «промежуточное звено» теории эволюции черных дыр.Эта черная дыра расположена на расстоянии примерно 26000 световых лет, или 7,9 килопарсека, от Земли в шаровом скоплении звезд под названием NGC 6624. Шаровое скопление звезд представляет собой гравитационно связанную группу из миллионов старых звезд, занимающих область пространства всего лишь порядка нескольких световых лет в диаметре.

Эта команда, возглавляемая доктором Бенетге Перерой (Benetge Perera) обнаружила свидетельства того, что миллисекундный пульсар PSR B1820-30A – сильно намагниченная, стремительно вращающаяся нейтронная звезда, которая излучает поток электромагнитного излучения – расположенный внутри скопления NGC 6624, вероятно, обращается вокруг черной дыры промежуточной массы (intermediate-mass black hole, IMBH), расположенной в центре скопления. Масса этой черной дыры по оценкам довольно велика и составляет примерно 7500 масс Солнца.

PSR B1820 30A является ближайшим к Земле известным науке пульсаром, расположенным в центре шарового скопления звезд, а также первым известным науке пульсаром, обращающимся вокруг черной дыры. Обнаружение IMBH имеет большое значение для астрономии, поскольку помогает понять связь между черными дырами звездных масс, представляющими собой самую небольшую по размерам разновидность черной дыры, и сверхмассивными черными дырами, являющимися крупнейшими из объектов своего рода.