Black Holes Archives

April 29, 2016May 15, 2016 by Evan Gough

Fermi Links Neutrino Blast To Known Extragalactic Blazar

This image shows the galaxy PKS B1424-418, and the blazar that lives there. The dotted circle is the area in which Fermi detected the neutrino Big Bird. Image: NASA/DOE/LAT Collaboration.

A unique observatory buried deep in the clear ice of the South Pole region, an orbiting observatory that monitors gamma rays, a powerful outburst from a black hole 10 billion light years away, and a super-energetic neutrino named Big Bird. These are the cast of characters that populate a paper published in Nature Physics, on Monday April 18th.

The observatory that resides deep in the cold dark of the Antarctic ice has one job: to detect neutrinos. Neutrinos are strange, standoffish particles, sometimes called ‘ghost particles’ because they’re so difficult to detect. They’re like the noble gases of the particle world. Though neutrinos vastly outnumber all other atoms in our Universe, they rarely interact with other particles, and they have no electrical charge. This allows them to pass through normal matter almost unimpeded. To even detect them, you need a dark, undisturbed place, isolated from cosmic rays and background radiation.

This explains why they built an observatory in solid ice. This observatory, called the IceCube Neutrino Observatory, is the ideal place to detect neutrinos. On the rare occasion when a neutrino does interact with the ice surrounding the observatory, a charged particle is created. This particle can be either an electron, muon, or tau. If these charged particles are of sufficiently high energy, then the strings of detectors that make up IceCube can detect it. Once this data is analyzed, the source of the neutrinos can be known.

The next actor in this scenario is NASA’s Fermi Gamma-Ray Space Telescope. Fermi was launched in 2008, with a specific job in mind. Its job is to look at some of the exceptional phenomena in our Universe that generate extraordinarily large amounts of energy, like super-massive black holes, exploding stars, jets of hot gas moving at relativistic speeds, and merging neutron stars. These things generate enormous amounts of gamma-ray energy, the part of the electromagnetic spectrum that Fermi looks at exclusively.

Next comes PKS B1424-418, a distant galaxy with a black hole at its center. About 10 billion years ago, this black hole produced a powerful outburst of energy, called a blazar because it’s pointed at Earth. The light from this outburst started arriving at Earth in 2012. For a year, the blazar in PKS B1424-418 shone 15-30 times brighter in the gamma spectrum than it did before the burst.

Detecting neutrinos is a rare occurrence. So far, IceCube has detected about a hundred of them. For some reason, the most energetic of these neutrinos are named after characters on the popular children’s show called Sesame Street. In December 2012, IceCube detected an exceptionally energetic neutrino, and named it Big Bird. Big Bird had an energy level greater than 2 quadrillion electron volts. That’s an enormous amount of energy shoved into a particle that is thought to have less than one millionth the mass of an electron.

The IceCube Neutrino Observatory is a series of strings of detectors, drilled deep into the Antarctic ice. Image: Nasa-verve - IceCube Science Team - Francis Halzen, Department of Physics, University of Wisconsin, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=26350372 — The IceCube Neutrino Observatory is a series of strings of detectors, drilled deep into the Antarctic ice. Image: Nasa-verve – IceCube Science Team – Francis Halzen, Department of Physics, University of Wisconsin, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=26350372

Big Bird was clearly a big deal, and scientists wanted to know its source. IceCube was able to narrow the source down, but not pinpoint it. Its source was determined to be a 32 degree wide patch of the southern sky. Though helpful, that patch is still the size of 64 full Moons. Still, it was intriguing, because in that patch of sky was PKS B1424-418, the source of the blazar energy detected by Fermi. However, there are also other blazars in that section of the sky.

The scientists looking for Big Bird’s source needed more data. They got it from TANAMI, an observing program that used the combined power of several networked terrestrial telescopes to create a virtual telescope 9,650 km(6,000 miles) across. TANAMI is a long-term program monitoring 100 active galaxies that are located in the southern sky. Since TANAMI is watching other active galaxies, and the energetic jets coming from them, it was able to exclude them as the source for Big Bird.

The team behind this new paper, including lead author Matthias Kadler of the University of Wuerzberg in Germany, think they’ve found the source for Big Bird. They say, with only a 5 percent chance of being wrong, that PKS B1424-418 is indeed Big Bird’s source. As they say in their paper, “The outburst of PKS B1424–418 provides an energy output high enough to explain the observed petaelectronvolt event (Big Bird), suggestive of a direct physical association.”

So what does this mean? It means that we can pinpoint the source of a neutrino. And that’s good for science. Neutrinos are notoriously difficult to detect, and they’re not that well understood. The new detection method, involving the Fermi Telescope in conjunction with the TANAMI array, will not only be able to locate the source of super-energetic neutrinos, but now the detection of a neutrino by IceCube will generate a real-time alert when the source of the neutrino can be narrowed down to an area about the size of the full Moon.

This promises to open a whole new window on neutrinos, the plentiful yet elusive ‘ghost particles’ that populate the Universe.

April 15, 2016April 15, 2016 by Evan Gough

A Super-Fast Star System Shrugs Its Shoulders At Physics

This annotated artist's conception illustrates our current understanding of the structure of the Milky Way galaxy. Image Credit: NASA

Astronomers have found a pair of stellar oddballs out in the edges of our galaxy. The stars in question are a binary pair, and the two companions are moving much faster than anything should be in that part of the galaxy. The discovery was reported in a paper on April 11, 2016, in the Astrophysical Journal Letters.

The binary system is called PB3877, and at 18,000 light years away from us, it’s not exactly in our neighborhood. It’s out past the Scutum-Centaurus Arm, past the Perseus Arm, and even the Outer Arm, in an area called the galactic halo. This binary star also has the high metallicity of younger stars, rather than the low metallicity of the older stars that populate the outer reaches. So PB3877 is a puzzle, that’s for sure.

PB3877 is what’s called a Hyper-Velocity Star (HVS), or rogue star, and though astronomers have found other HVS’s, more than 20 of them in fact, this is the first binary one found. The pair consists of a hot sub-dwarf primary star that’s over five times hotter than the Sun, and a cooler companion star that’s about 1,000 degrees cooler than the Sun.

Hyper-Velocity stars are fast, and can reach speeds of up to 1,198 km. per second, (2.7 million miles per hour,) maybe faster. At that speed, they could cross the distance from the Earth to the Moon in about 5 minutes. But what’s puzzling about this binary star is not just its speed, and its binary nature, but its location.

Hyper-Velocity stars themselves are rare, but PB3877 is even more rare for its location. Typically, hyper velocity stars need to be near enough to the massive black hole at the center of a galaxy to reach their incredible speeds. A star can be drawn toward the black hole, accelerated by the unrelenting pull of the hole, then sling-shotted on its way out of the galaxy. This is the same action that spacecraft can use when they gain a gravity assist by travelling close to a planet.

This video shows how stars can accelerate when their orbit takes them close to the super-massive black holes at the center of the Milky Way.

But the trajectory of PB3877 shows astronomers that it could not have originated near the center of the galaxy. And if it had been ejected by a close encounter with the black hole, how could it have survived with its binary nature intact? Surely the massive pull of the black hole would have destroyed the binary relationship between the two stars in PB3877. Something else has accelerated it to such a high speed, and astronomers want to know what, exactly, did that, and how it kept its binary nature.

Barring a close encounter with the super-massive black hole at the center of the Milky Way, there are a couple other ways that PB3877 could have been accelerated to such a high velocity.

One such way is a stellar interaction or collision. If two stars were travelling at the right vectors, a collision between them could impart energy to one of them and propel it to hyper-velocity. Think of two pool balls on a pool table.

Another possibility is a supernova explosion. It’s possible for one of the stars in a binary pair to go supernova, and eject it’s companion at hyper-velocity speeds. But in these cases, either stellar collision or supernova, things would have to work out just right. And neither possibility explains how a wide-binary system like this could stay intact.

Fraser Cain sheds more light on Hyper-Velocity Stars, or Rogue Stars, in this video.

There is another possibility, and it involves Dark Matter. Dark Matter seems to lurk on the edge of any discussion around something unexplained, and this is a case in point. The researchers think that there could be a massive cocoon or halo of Dark Matter around the binary pair, which is keeping their binary relationship intact.

As for where the binary star PB3788 came from, as they say in the conclusion of their paper, “We conclude that the binary either formed in the halo or was accreted from the tidal debris of a dwarf galaxy by the Milky Way.” And though the source of this star’s formation is an intriguing question, and researchers plan follow up study to verify the supernova ejection possibility, its possible relationship with Dark Matter is also intriguing.

April 7, 2016April 15, 2016 by Evan Gough

Supermassive Black Hole Found In The Cosmic Boonies

A supermassive black hole has been found in an unusual spot: an isolated region of space where only small, dim galaxies reside. Image credit: NASA/JPL-Caltech — A team of astronomers from South Africa have noticed a series of supermassive black holes in distant galaxies that are all spinning in the same direction. Credit: NASA/JPL-Caltech

Astronomers have found a massive black hole in a place they never expected to find one. The hole comes in at 17 billion solar masses, which makes it the second largest ever found. (The largest is 21 billion solar masses.) And though its enormous mass is noteworthy, its location is even more intriguing.

Supermassive black holes are typically found at the centers of huge galaxies. Most galaxies have them, including our own Milky Way galaxy, where a comparatively puny 4 million solar mass black hole is located. Not only that, these gargantuan holes tend to be located in galaxies that are part of a large cluster of galaxies. Being surrounded by all that mass is a prerequisite for the formation of supermassive black holes. The largest one known, at 21 billion solar masses, is located in a very dense region of space called the Coma Cluster, where over 1,000 galaxies have been identified.

The largest supermassive holes also tend to be surrounded by bright companions, who have also grown large from the plentiful mass in their surroundings. (Of course, its not the black holes that are bright, but the quasars that surround them.) The long and the short of it is that supermassive black holes are usually found in galaxy clusters, and usually have other supermassive companions in the same region of space. They’re not found in isolation.

But this newly found black hole is in a rather sparse region of space. It’s in NGC 1600, an elliptical galaxy in the constellation Eridanus, 200 million light years from Earth. NGC 1600 is not a particularly large galaxy, and though it has been considered part of a larger group of galaxies, all its companions are much dimmer in comparison. So NGC 1600 is a rather small, isolated galaxy, with only a few dim companions.

A supermassive black hole of 17 billion solar masses has been found in the elliptical galaxy NGC 1600, a rather isolated galaxy with only dim companions. To date, supermassive black holes have only been found in huge galaxies at the centre of large clusters of galaxies. This image is a composite image from the Hubble and from ground observatories. Image Credit: NASA/ESA/Digital Sky Survey 2.

There’s another way that supermassive holes can form. Instead of growing large over time, by feeding on the mass of their home galaxies and galaxy clusters, they can form when two galaxies merge, and two smaller holes become one. But even this requires that they be in a region where galaxies are plentiful, allowing for more collisions and mergers.

It may be possible that NGC is the result of a merger of two galaxies, or that it is two black holes that are currently merging. Or it could be that NGC 1600’s region of space was once extremely rich in gas, in the early days of the Universe, and that’s what gave rise to this ‘out of place’ supermassive black hole.

There is much to be learned about the conditions that give rise to these behemoth black holes. The MASSIVE study will combine several telescopes to survey and catalogue the largest galaxies and black holes. This should tell astronomers a lot about their distribution, and about the circumstances that allow them to exist. We might find even larger ones.

March 29, 2016 by Evan Gough

Japan’s Black Hole Telescope Is In Trouble

An artist's drawing of Japan's Hitomi observatory. Image Credit: JAXA/Akihiro Ikeshita

The Japanese Aerospace Exploration Agency (JAXA) has lost contact with its X-ray Astronomy Satellite Hitomi (ASTRO-H.) Hitomi was launched on February 17th, for a 3-year mission to study black holes. But now that mission appears to be in jeopardy.

Hitomi is a collaboration between JAXA and NASA. Its mission was to investigate how galaxy clusters were formed and influenced by dark matter and dark energy, and to understand how super-massive black holes form and evolve at the center of galaxies. Hitomi was also to “unearth the physical laws governing extreme conditions in neutron stars and black holes,” according to JAXA.

Japan has managed two very short communications with Hitomi, but they were very brief, and JAXA has not been able to determine the nature of the problem. Now, JSpOC, the US Joint Space Operations Center, say they have detected debris in the vicinity of Hitomi, and in a press release this morning (March 29th), JAXA says “it is estimated that Hitomi separated to five pieces at about 10:42 a.m.”

Hitomi was going to be an important contribution to the fleet of space telescopes used by astrophysicists and cosmologists. It has a cutting edge instrument called the X-ray micro-calorimeter, which would have observed X-rays from space with the greatest sensitivity of any instrument so far. If all that is lost, it will be quite a blow.

There’s no definitive word yet on what exactly has happened to Hitomi. Japan is using ground stations in different parts of the world to try to communicate with their observatory. It’s important to note that there is no agreement that the craft has broken apart. The press releases are translations from Japanese to English, so the exact meaning of “separated to five pieces” is unclear.

It’s possible that there was a small explosion of some sort, and that some debris from that explosion is in the vicinity of Hitomi. It’s also possible that JAXA will re-establish communications with the craft as time goes on.

Other observatories have suffered serious problems, and have eventually been brought back under control and completed their missions. The ESA/NASA Solar and Heliospheric Observatory (SOHO) suffered serious problems at the beginning of its mission in 1995, entering emergency mode 3 times before all contact was lost. Eventually, SOHO was brought under control, and what was supposed to be a 2-year mission has lasted 20.

Universe Today will be following this story to see if Hitomi can be made operational. For readers wanting to know more about Hitomi’s mission, read JAXA’s excellent Hitomi press kit.

March 18, 2016February 23, 2017 by Fraser Cain

Where is the Closest Black Hole?

Black_Hole_in_the_universe — If you saw this, it would already be too late. Credit: NASA

You know that saying, “keep your friends close, but keep your enemies closer?” That advice needs to go right out the window when we’re talking black holes. They’re the worst enemies you could have and you want them as far away as possible.

We’re talking regions of space where matter is compressed so densely that the only way to escape is to be traveling faster than the speed of light. And as we know, you can’t go faster than the speed of light. So… there’s no escape.

Get too close to the black hole and you’ll be compressed beyond comprehension, perhaps into an infinitely small point.

But you can be reasonably distant from a black hole too, and still have your day ruined. A black hole reaches out through the light years with its gravity. And if one were to wander too close to our Solar System, it would wreak havoc on all our precious planets.

The planets and even the Sun would be gobbled up, or smashed together, or even thrown out of the Solar System entirely.

And as we learned in a previous episode, black holes are unkillable. Anything you might try to do to them just makes them bigger, stronger and angrier. Your only hope is to just wait them out over the eons it takes for them to evaporate.

It makes sense to keep track of all the black holes out there, just in case we might need to evacuate this Solar System in a hurry.

Where are the closest black holes?

There are two kinds of black holes out there: the supermassive black holes at the heart of every galaxy, and the stellar mass black holes formed when massive stars die in a supernova.

This artist’s impression shows the surroundings of the supermassive black hole at the heart of the active galaxy NGC 3783. Credit: ESO/M. Kornmesser

The supermassive ones are relatively straightforward. There’s one at the heart of pretty much every single galaxy in the Universe. One in the middle of the Milky Way, located about 27,000 light-years away. One in Andromeda 2.5 million light years away, and so on.

No problem, they supermassive ones are really far away, no threat to us.

The stellar mass ones might be more of a problem.

Here’s the problem. Black holes don’t emit any radiation, they’re completely invisible, so there’s no easy way to see them in the sky. The only you’d know there’s a black hole is if you were close enough to see the background starlight getting distorted. And if you’re close enough to see that, you’re already dead.

The closest black hole we know of is V616 Monocerotis, also known as V616 Mon. It’s located about 3,000 light years away, and has between 9-13 times the mass of the Sun. We know it’s there because it’s located in a binary system with a star with about half the mass of the Sun. Only a black hole could make its binary partner buzz around so quickly. Astronomers can’t see the black hole, they just know it’s there by the whirling gravity dance.

The next closest black hole is the classic Cygnus X-1, which is about 6,000 light-years away. It has about 15 times the mass of the Sun, and once again, it’s in a binary system.

The third closest black hole, is also in a binary system.

Artist's illustration of Cygnus X-1. Credit: NASA/CXC/M.Weiss — Artist’s illustration of Cygnus X-1, a stellar-mass black hole in a binary system. Credit: NASA/CXC/M.Weiss

See the problem here? The reality is that a fraction of black holes are in binary systems, but that’s our only way to detect them.

More likely there are more black holes much more close than the ones astronomers have been able to discover.

This all sounds terrifying, I’m sure, and now you’ve probably got one eye on the sky, watching for that telltale distortion of light from an approaching black hole. But these events are impossibly rare.

The Solar System has been around for more than 4.5 billion years, with all the planets going around and around without interruption. Even if a black hole passed the Solar System within a few dozen light years, it would have messed up the orbits significantly, and life probably wouldn’t be here to consider this fact.

We didn’t encounter a black hole in billions of years, and probably won’t encounter one for billions or trillions more years.

Sadly, the answer to this question is… we don’t know. We just don’t know if the closest black holes is a few light years away, or it’s actually V616 Mon. We’ll probably never know.

But that’s fine. They’re so rare it’s not worth worrying about.

March 14, 2016February 23, 2017 by Fraser Cain

What are the Different Kinds of Supernovae?

There are a few places in the Universe that defy comprehension. And supernovae have got to be the most extreme places you can imagine. We’re talking about a star with potentially dozens of times the size and mass of our own Sun that violently dies in a faction of a second.

Faster than it take me to say the word supernova, a complete star collapses in on itself, creating a black hole, forming the denser elements in the Universe, and then exploding outward with the energy of millions or even billions of stars.

But not in all cases. In fact, supernovae come in different flavours, starting from different kinds of stars, ending up with different kinds of explosions, and producing different kinds of remnants.

There are two main types of supernovae, the Type I and the Type II. I know this sounds a little counter intuitive, but let’s start with the Type II first.

These are the supernovae produced when massive stars die. We’ve done a whole show about that process, so if you want to watch it now, you can click here.

Our eyes would never see the Crab Nebula as this Hubble image shows it. Image credit: NASA, ESA, J. Hester and A. Loll (Arizona State University)

But here’s the shorter version.

Stars, as you know, convert hydrogen into fusion at their core. This reaction releases energy in the form of photons, and this light pressure pushes against the force of gravity trying to pull the star in on itself.

Our Sun, doesn’t have the mass to support fusion reactions with elements beyond hydrogen or helium. So once all the helium is used up, the fusion reactions stop and the Sun becomes a white dwarf and starts cooling down.

But if you have a star with 8-25 times the mass of the Sun, it can fuse heavier elements at its core. When it runs out of hydrogen, it switches to helium, and then carbon, neon, etc, all the way up the periodic table of elements. When it reaches iron, however, the fusion reaction takes more energy than it produces.

The outer layers of the star collapses inward in a fraction of a second, and then detonates as a Type II supernova. You’re left with an incredibly dense neutron star as a remnant.

But if the original star had more than about 25 times the mass of the Sun, the same core collapse happens. But the force of the material falling inward collapses the core into a black hole.

Extremely massive stars with more than 100 times the mass of the Sun just explode without a trace. In fact, shortly after the Big Bang, there were stars with hundreds, and maybe even thousands of times the mass of the Sun made of pure hydrogen and helium. These monsters would have lived very short lives, detonating with an incomprehensible amount of energy.

Artist's impression of a supernova — Artist’s impression of a supernova

Those are Type II. Type I are a little rarer, and are created when you have a very strange binary star situation.

One star in the pair is a white dwarf, the long dead remnant of a main sequence star like our Sun. The companion can be any other type of star, like a red giant, main sequence star, or even another white dwarf.

What matters is that they’re close enough that the white dwarf can steal matter from its partner, and build it up like a smothering blanket of potential explosiveness. When the stolen amount reaches 1.4 times the mass of the Sun, the white dwarf explodes as a supernova and completely vaporizes.

In a Type Ia supernova, a white dwarf (left) draws matter from a companion star until its mass hits a limit which leads to collapse and then explosion. Credit: NASA

Because of this 1.4 ratio, astronomers use Type Ia supernovae as “standard candles” to measure distances in the Universe. Since they know how much energy it detonated with, astronomers can calculate the distance to the explosion.

There are probably other, even more rare events that can trigger supernovae, and even more powerful hypernovae and gamma ray bursts. These probably involve collisions between stars, white dwarfs and even neutron stars.

As you’ve probably heard, physicists use particle accelerators to create more massive elements on the Periodic Table. Elements like ununseptium and ununtrium. It takes tremendous energy to create these elements in the first place, and they only last for a fraction of a second.

But in supernovae, these elements would be created, and many others. And we know there are no stable elements further up the periodic table because they’re not here today. A supernova is a far better matter cruncher than any particle accelerator we could ever imagine.

Next time you hear a story about a supernova, listen carefully for what kind of supernova it was: Type I or Type II. How much mass did the star have? That’ll help your imagination wrap your brain around this amazing event.

February 18, 2016March 18, 2016 by Evan Gough

Did a Gamma Ray Burst Accompany LIGO’s Gravity Wave Detection?

An artist's impression of a Gamma Ray Burst. Credit: Stanford.edu

Last week’s announcement that Gravitational Waves (GW) have been detected for the first time—as a result of the merger of two black holes—is huge news. But now a Gamma Ray Burst (GRB) originating from the same place, and that arrived at Earth 0.4 seconds after the GW, is making news. Isolated black holes aren’t supposed to create GRB’s; they need to be near a large amount of matter to do that.

NASA’s Fermi telescope detected the GRB, coming from the same point as the GW, a mere 0.4 seconds after the waves arrived. Though we can’t be absolutely certain that the two phenomena are from the same black hole merger, the Fermi team calculates the odds of that being a coincidence at only 0.0022%. That’s a pretty solid correlation.

So what’s going on here? To back up a little, let’s look at what we thought was happening when LIGO detected gravitational waves.

Our understanding was that the two black holes orbited each other for a long time. As they did so, their massive gravity would have cleared the area around them of matter. By they time they finished circling each other and merged, they would have been isolated in space. But now that a GRB has been detected, we need some way to account for it. We need more matter to be present.

According to Abraham Loeb, of Harvard University, the missing piece of this puzzle is a massive star—itself the result of a binary star system combining into one—a few hundred times larger than the Sun, that spawned two black holes. A star this size would form a black hole when it exhausted its fuel and collapsed. But why would there be two black holes?

Again, according to Loeb, if the star was rotating at a high enough rate—just below its break up frequency—the star could actually form two collapsing cores in a dumbbell configuration, and hence two black holes. But now these two black holes would not be isolated in space, they would actually be inside a massive star. Or what was left of one. The remnants of the massive star is the missing matter.

When the black holes joined together, an outflow would be generated, which would produce the GRB. Or else the GRB came “from a jet originating out of the accretion disk of residual debris around the BH remnant,” according to Loeb’s paper. So why the 0.4 s delay? This is the time it took the GRB to cross the star, relative to the gravitational waves.

It sounds like a nice tidy explanation. But, as Loeb notes, there are some problems with it. The main question is, why was the GRB so weak, or dim? Loeb’s paper says that “observed GRB may be just one spike in a longer and weaker transient below the GBM detection threshold.”

But was the GRB really weak? Or was it even real? The European Space Agency has their own gamma ray detecting spacecraft, called Integral. Integral was not able to confirm the GRB signal, and according to this paper, the gamma ray signal was not real after all.

As they say in show business, “Stay tuned.”

February 11, 2016March 18, 2016 by Evan Gough

Gravitational Waves Discovered: A New Window on the Universe

An illustration of Markarian 231, a binary black hole 1.3 billion light years from Earth. Their collision generated the first gravitational waves we've ever detected. Image: NASA

“Ladies and Gentlemen, we have detected gravitational waves. We did it.”

With those words, Dave Reitze, executive director of the U.S.-based Laser Interferometry Gravitational-Wave Observatory (LIGO), has opened a new window into the universe, and ushered in a new era in space science.

Predicted over 100 years ago by Albert Einstein, gravitational waves are ripples in space-time. They travel in waves, like light does, but they aren’t radiation. They are actual perturbations in the fabric of space-time itself. The ones detected by LIGO, after over ten years of “listening”, came from a binary system of black holes over 1.3 billion light years away, called Markarian 231.

The two black holes, each 30 times as massive as the Sun, orbited each other, then spiralled together, ultimately colliding and merging together. The collision sent gravitational waves rippling through space time.

LIGO, which is actually two separate facilities separated by over 3,000 km, is a finely tuned system of lasers and sensors that can detect these tiny ripples in space-time. LIGO is so sensitive that it can detect ripples 10,000 times smaller than a proton, in laser beams 4 kilometres long.

The Laser Interferometer Gravitational-Wave Observatory (LIGO)facility in Livingston, Louisiana. The other facility is located in Hanford, Washington. Image: LIGO

Light is—or has been up until now—the only way to study objects in the universe. This includes everything from the Moon, all the way out to the most distant objects ever observed. Astronomers and astrophysicists use observatories that can see in not only visible light, but in all other parts of the electromagnetic spectrum, to study objects in the universe. And we’ve learned an awful lot. But things will change with this announcement.

“I think we’re opening a window on the universe,” Dave Reitze said.

Another member of the team that made this discovery, astrophysicist Szabolcs Marka from Columbia University, said, “Until this moment we had our eyes on the sky and we couldn’t hear the music.”

Gravitational waves are a new way to study notoriously difficult things to observe like black holes and neutron stars. Black holes emit no light at all, and their characteristics and properties are inferred from cause and effect relationships with objects near them. But the detection of gravitational waves holds the promise of answering questions about black holes, neutron stars, and even the early days of our universe, including the Big Bang.

It’s almost impossible to overstate the magnitude of this discovery. Once we understand how to better detect and observe gravitational waves, we may come to a whole new understanding of the universe, and we may look back on this day as truly ground-breaking and revolutionary.

And it all started 100 years ago with Albert Einstein’s prediction.

For a better understanding of Gravitational Waves, their sources, and their detection, check out Markus Possel’s excellent series of articles:

Gravitational Waves and How They Distort Space

Gravitational Wave Detectors and How They Work

Sources of Gravitational Waves: The Most Violent Events in the Universe

February 5, 2016March 27, 2017 by Fraser Cain

Weekly Space Hangout – Feb. 5, 2016: Dr. Or Graur

Host: Fraser Cain (@fcain)

Special Guest: Dr. Or Graur, Research Associate at the Center for Cosmology and Particle Physics at New York University; Researches what type of star leads to a thermonuclear, or “Type Ia,” supernova.

Guests:
Carolyn Collins Petersen (thespacewriter.com / space.about.com / @spacewriter )
Morgan Rehnberg (cosmicchatter.org / @MorganRehnberg )
Jolene Creighton (fromquarkstoquasars.com / @futurism)
Alessondra Springmann (@sondy)

Continue reading “Weekly Space Hangout – Feb. 5, 2016: Dr. Or Graur”

February 4, 2016March 18, 2016 by Evan Gough

The Highest-Resolution Image Ever Seen in Astronomy

A jet of material being ejected out of a black hole at the centre of the galaxy BL Lacertae. Image: Dr. Jose L. Gomez

What do you get when you combine 15 radio telescopes on Earth and one in space? You get an enormous “virtual telescope” that is 63,000 miles across. And when you point it at a distant black hole, you get the highest resolution image every seen in astronomy.

Although it looks just like a big green blob, it’s actually an enormously energetic jet of matter streaming out of a black hole. And this black hole is 900 million light years away.

As reported at Popular Science, it required an array of 15 radio telescopes on Earth, and the Russian space telescope Spektr-R, to capture the image. This technique—called interferometry—is like creating a telescope that is 63,000 miles across. The detail it provides is like seeing a 50 cent coin on the Moon.

For perspective, the object in the image is 186 billion miles long, at minimum, and would just barely fit in the Oort Cloud.