Two massive black holes colliding into each other created ripples in space and time, known as gravitational waves, which have been detected at the furthest distance yet, international physicists said Thursday.

The galactic mash-up which produced the gravitational waves occurred some three billion light-years away, and marks the science world's third observation of this phenomenon.

The finding further bolsters Einstein's 1915 theory of general relativity, and comes two years after these enigmatic ripples were first detected, said the report in the journal Physical Review Letters.

"It is remarkable that humans can put together a story, and test it, for such strange and extreme events that took place billions of years ago and billions of light-years distant from us," said David Shoemaker, spokesman for the Laser Interferometer Gravitational-wave Observatory (LIGO) Scientific Collaboration.

The group includes more than 1,000 international scientists who perform LIGO research together with the European-based Virgo Collaboration.

In all three cases, each of the twin detectors of LIGO detected gravitational waves from the tremendously energetic mergers of black hole pairs.

"These are collisions that produce more power than is radiated as light by all the stars and galaxies in the universe at any given time," said a LIGO statement.

The latest black hole collision, resulting in a detectable "chirp" of a gravitational wave, happened when two black holes merged, forming a new one that is about 49 times the mass of the Sun.

Its size is smack in the middle of the first such black hole merger detected by LIGO, at 62 solar masses, and the second which had 21.

"We have further confirmation of the existence of stellar-mass black holes that are larger than 20 solar masses -- these are objects we didn't know existed before LIGO detected them," said Shoemaker, a senior research scientist at the Massachusetts Institute of Technology (MIT).

The first-ever direct observation of gravitational waves was made in September 2015, and detected an event some 1.3 billion light-years away.

The second came shortly after, in December 2015, and was a distance of 1.4 billion light-years.

The third detection, called GW170104, was made on January 4, 2017.

"With the third confirmed detection of gravitational waves from the collision of two black holes, LIGO is establishing itself as a powerful observatory for revealing the dark side of the universe," says David Reitze of Caltech, executive director of the LIGO Laboratory.

"While LIGO is uniquely suited to observing these types of events, we hope to see other types of astrophysical events soon, such as the violent collision of two neutron stars."

LIGO's observations are carried out by twin detectors -- one in Hanford, Washington, and the other in Livingston, Louisiana.

The observatories, which use laser interferometers to sense the presence of gravitational waves, are operated by Caltech and MIT with funding from the National Science Foundation (NSF).

"It looks like Einstein was right -- even for this new event, which is about two times farther away than our first detection," said Laura Cadonati, an associate professor at the Georgia Institute of Technology.

"We can see no deviation from the predictions of general relativity, and this greater distance helps us to make that statement with more confidence." </s> HALIFAX - Astronomers have discovered the beginnings of what they say is a gigantic cosmic pileup that could someday form one of the largest structures in the universe.

The team of Canadian and international scientists say they used a powerful telescope to detect the "impending collision of 14 young, starbursting galaxies" that will become a massive galaxy cluster.

The research, published in the journal Nature, says the so-called protocluster or group of galaxies is 12.4 billion light years away — suggesting its light began travelling to Earth when the universe was 1.4 billion years old.

One of the researchers, astrophysicist Scott Chapman of Dalhousie University, says the discovery challenges conventional understanding of how structures form in the universe since it happened so quickly and in a space only about three times the size of the Milky Way.

Until now, astronomers had theorized that protoclusters as large as this one would have taken much longer to form. </s> Center of Milky Way may have thousands of black holes, study says

New detailed 3D map of Milky Way to 'revolutionize astronomy'

Astronomers have detected the early stages of a colossal cosmic collision, observing a pile-up of 14 galaxies 90 percent of the way across the observable universe in a discovery that upends assumptions about the early history of the cosmos.

Researchers said on Wednesday the galactic mega-merger observed 12.4 billion light-years away from Earth occurred 1.4 billion years after the Big Bang that gave rise to the universe. Astronomers call the object a galactic protocluster, a precursor to the type of enormous galaxy clusters that are the largest-known objects in today's universe.

It marked the first time scientists observed the birth of a galaxy cluster, with at least 14 galaxies crammed into an area only about four times the size of our average-sized Milky Way galaxy.

A protocluster as massive as the one observed here, designated as SPT2349-56, should not have existed at that time, according to current notions of the early universe. Scientists had figured this could not happen until several billion of years later.

"We were staggered by the implications," said astrophysicist Scott Chapman of Dalhousie University in Canada. "Yes, conventional wisdom was that clusters take a lot longer to build up and assemble. SPT2349 shows us it happened much more rapidly and explosively than simulations or theory suggested."

Galaxy clusters can have thousands of galaxies bound together by gravity that can boast total masses a quadrillion larger than our sun, with immense amounts of the enigmatic material called dark matter, gigantic black holes and super-heated gas.

SPT2349's mass is about 10 trillion times larger than our sun.

The galaxies within SPT2349 were producing stars at a remarkable clip, up to a thousand times the Milky Way's star-formation rate.

In observing objects so distant, astronomers are peering back in history because of the length of time light takes to travel. SPT2349-56 appeared when the universe was about a tenth its current age.

"This result is exciting as it allows us to directly study the formation of a massive galaxy cluster in the early universe," Yale University astronomer Tim Miller added.

The researchers, who studied SPT2349 using land-based telescopes in Chile, said it most likely has snowballed in size since 12.4 billion years ago and could be among the largest structures in the cosmos today.

The research was published in the journal Nature. </s> Spotting objects in space has gotten easier and easier thanks to technological advances, but sometimes mother nature gives astronomers a bit of help as well. Scientists using the trust Hubble Space Telescope have announced the discovery of the most distant star ever observed, and it’s really, really far out there. The star, named MACS J1149 LS1 (LS1 for short), is so far away that the light researchers see from it today was produced just 4.4 billion years after the Big Bang.

Remarkably, the scientist who spotted the star weren’t even really looking for it at all. The team was originally studying a supernova explosion in a galaxy cluster known as MACS J1149.5-223 when they realized a tiny blue dot in their view was actually a star in the distant background. Now the unexpected discovery is being used to demonstrate how the phenomenon of gravitational lensing can be used to detect objects we’d never be able to see on our own.

Gravitational lensing occurs when the light of a far-off object, like a star, is bent and stretched by the gravity of a different body lying between the observer and the object itself. As the light bends due to gravity it is magnified, allowing it to be observed from a much larger distance. LS1, which stands for Lensed Star 1, is the first individual star to be spotted in this manner, and its light has been magnified over 2,000 times by the gravitational lens.

“You can see individual galaxies out there, but this star is at least 100 times farther away than the next individual star we can study, except for supernova explosions,” Patrick Kelly of the University of Minnesota, Twin Cities, explains. Kelly is one of the authors of a new paper in Nature Astronomy describing the discovery.

The star is so far away that it is thought to be around 100 times more distant than the next farthest star ever observed. That figures out to around nine billion light years, which is so far that there’s no way we’d ever have been able to see it without the gravity assist. Very little is known about the star itself, aside from the fact that it exists, but at this point the discovery itself is still a remarkable achievement. </s> Astronomers have for the first time witnessed a colossal merger of 14 galaxies that took place more than 12 billion years ago – providing a starting point into how galaxies evolve.

In a study published in the journal Nature, a team of international scientists used computer simulations of the galaxies to predict that, over time, this massive cluster will assemble to become the biggest structure in the modern universe.

Here’s all you need to know:

So why are we just seeing this megamerger now?

This densely-packed galactic smash-up, known as a protocluster, is located approximately 12.4 billion light years away.

This means its light started travelling when the universe was only 1.4 billion years old – about a 10th of its present age – and has just reached us.

Scott Chapman, an astrophysicist at Dalhousie University in Halifax, Canada – and one of the study authors, said: “Having caught a massive galaxy cluster in throes of formation is spectacular in and of itself.

“But, the fact that this is happening so early in the history of the universe poses a formidable challenge to our present-day understanding of the way structures form in the universe.”

How did the astronomers see this cosmic pile-up?

Using a powerful telescope called the Atacama Large Millimetre/submillimetre Array (Alma) in Chile, astronomers peered deep into space to witness the beginnings of the gargantuan merger.

The cosmic pile-up was observed “an astounding 90% of the way across the observable universe”, according to the team.

Alma allowed astronomers to identify 14 starburst galaxies undergoing an exceptionally high rate of star formation in a small region of space, confirming that this was a protocluster, called SPT2349-56, in very early stages of development.

Chapman said: “Alma gave us, for the first time, a clear starting point to predict the evolution of a galaxy cluster.”

So what does this all mean?

The scientists say a protocluster as massive SPT2349-56 should have taken much longer to evolve – because they are likely to contain vast amounts of dark matter and gargantuan black holes.

Tim Miller, a doctoral candidate at Yale University and co-author on the paper, said: “How this assembly of galaxies got so big so fast is a bit of a mystery, it wasn’t built up gradually over billions of years, as astronomers might expect.”

Computer simulations indicate that, over the next billion years or so, the 14 galaxies will merge into one giant elliptical galaxy surrounded stars and cosmic dust.

The researchers estimate this mega cluster will have a mass equivalent to 1,000 trillion suns, which would make it the largest known object in the universe. </s> Image copyright NRAO/AUI/NSF/S. Dagnello Image caption An artist's impression of the 14 galaxies detected

Scientists have detected a cosmic "pileup" of galaxies in the early Universe.

Imaged almost at the boundary of the observable Universe, the 14 unusually bright objects are on a collision course, set to form one massive galaxy.

This will in turn serve as the core for a galaxy cluster, one of the most massive objects in the Universe.

The catch? This all happened over 12 billion years ago.

Looking this far across the Universe is essentially looking back in time, as the light has taken many billions of years to reach us.

The galaxies would have been in their observed configuration when the Universe was a mere 1.4 billion years old.

Image copyright ALMA; B. Saxton Image caption The galaxies are set to collide and merge

Originally detected in a wide sky survey using the South Pole Telescope, the objects surprised astronomers as they were clustered so close together.

"We found it originally as a bright point source in the survey," explained Yale University's Tim Miller, an author on the study published in Nature.

"I don't think we were expecting something quite this spectacular but we knew it had to be exciting."

Star nurseries

Known as starburst galaxies, the objects are extremely bright as they are forming stars at a high rate - up to 1,000 times as fast as the Milky Way.

Professor Caitlin Casey, who was not involved in the study, described the findings as "extremely unusual."

"We often get excited when we find just two galaxies like this grouped together, because each one is already quite unusual and rare compared to 'normal galaxies', forming stars several hundreds or thousands of times faster than the Milky Way. To find fourteen such starbursts all grouped together is unheard of," the University of Texas at Austin researcher commented.

Image copyright ESA/Hubble Image caption Starburst galaxies like NGC 1569 are regions of accelerated star birth

Crowded neighbourhood

The group occupy a region of space just four or five times the size of the Milky Way, making it incredibly dense.

"If you put all the planets into the orbit between the Earth and Moon, it's the same sort of scale of mass concentration," explained Dr Axel Weiß, a co-author on the study.

The question of why such a concentration of galaxies was able to evolve in this location, and so early in the Universe's history, remains unanswered for now.

"This is just so early. This is before the peak of star formation," says Miller.

Image copyright Science Photo Library Image caption About one star forms every year in the Milky Way

A long way to here

So what have these galaxies gotten up to in the intervening billions of years?

By now, models predict that they would have coalesced to form the core of an even more massive cluster.

Miller explains that in the present day, astronomers expect the structure would be as massive as the Coma Cluster.

Stretching across two degrees of the night sky, or over four times the visible space occupied by the full moon, the Coma Cluster is truly a giant.

"The uniqueness of the Coma Cluster is it's one of the most massive structures we know about in the whole local Universe. [It has about] 10,000 billion solar masses. It's the most extreme structure that we know about," explained Dr Weiß.

Thus far, very few of these large galaxy clusters have been detected, but work continues on further candidates.

Image copyright Science Photo Library Image caption The Coma Cluster contains over 1,000 galaxies

Dr Weiß, who was involved in another study which revealed a similar cluster of ten galaxies, says that there are some other candidates.

"[Though] these are certainly the most extreme ones," said the Max Planck Institute for Radio Astronomy scientist.

Dr Amy Barger, from the University of Wisconsin-Madison found the work to be "ground-breaking."

"Finding the progenitors of present-day massive clusters has always been of great importance for piecing together when and how structure grows in the Universe," she told BBC News. </s> For the third time, scientists have detected a spacetime rumble caused by a violent collision of two black holes. The Laser Interferometer Gravitational-wave Observatory (LIGO) made the detection, determining that the two black holes merged to create one large black hole in a galaxy about 3 billion light-years away.

"We have observed – on the 4th of January, 2017 – another massive black hole-black hole binary coalescence; the in-spiral and merging of black holes 20 and 30 times the mass of our sun," Dave Shoemaker, a senior research scientist who works at Massachusetts Institute of Technology (MIT) and the spokesperson for the LIGO Scientific Collaboration, told reporters during a special news briefing on Wednesday (May 31).

This gargantuan black hole smashup created an even more massive spinning black hole, approximately 49 times the mass of our sun. In an instant, the equivalent mass twice that of our sun was converted directly into gravitational waves — briefly producing more energy than all the energy that is radiated as light by all the galaxies in the universe at any moment, LIGO scientists say.

After many years of planning, development and construction, LIGO took its first observations in 2002. However, it wasn't until Sept. 14, 2015, that the first historic detection of gravitational waves — an event called "GW150914" — was made. That happened after LIGO underwent upgrades (known as Advanced LIGO) to boost its sensitivity. Then, a second detection ("GW151226") followed a few months later in December, confirming that the first discovery was no fluke.

Now, the LIGO Scientific Collaboration — which consists of over a thousand scientists around the world — has confirmed the third gravitational wave detection ("GW170104"), meaning we're at the cusp of a completely new kind of astronomy.

All the gravitational waves detected so far have been created by the collision of stellar-mass black holes of varied sizes. These are black holes that are a few to a few dozen times the mass of our sun that were likely formed by the death of very massive stars after they'd run out of fuel and exploded as supernovas billions of years ago. Advanced LIGO has reached a crossroads in our gravitational wave search, finally reaching a sensitivity that can detect when very distant black holes collide, creating faint gravitational waves that we now know fill our universe.

The 2015 events were caused by mergers creating black holes 62 and 21 solar masses in galaxies 1.3 and 1.4 billion light-years away, respectively. (Note: As gravitational waves travel at the speed of light these mergers happened 1.3 and 1.4 billion years ago.) This latest detection originated from a merger creating a black hole of 49 solar masses (another "heavy" black hole like the first one), but the merger happened over twice as far away than previous events.

"What this means is that we now have a second candidate in the "heavy" black hole category," says Bangalore Sathyaprakash, of Penn State and Cardiff University and a member of the LIGO Scientific Collaboration.

This is important as, before LIGO made its first detection (a 62 solar mass black hole) and its most recent one (a 49 solar mass black hole), there was no observational evidence that these large black holes even existed. This is an incredible early discovery. Scientists have revealed a brand-new type of large black hole in only three detections.

Things are about to get even more exciting as LIGO undergoes more planned upgrades and other observatories join the hunt for gravitational waves.

"We should expect to see one binary merger event per day once LIGO's designed sensitivity is reached," says Sathyaprakash.

When gravitational waves are detected the conditions of the colliding black holes at the time of the merger can be studied.

"In our analysis, we cannot measure the spins of the individual black holes very well, but we can tell if the black holes are generally spinning in the same direction as the orbital motion," says astrophysicist Laura Cadonati, LIGO Scientific Collaboration deputy spokesperson from Georgia Tech.

But an idea of the individual black hole's spin relative to one another can be figured out by studying the "fingerprint" of the gravitational wave signal, says Cadonati.

Theoretical models of merging black holes indicate that if the two black holes' spins are not aligned, the merging event will happen faster than if the spins are aligned. Also, additional wobbles in the signal are predicted as two spin-aligned black holes get close and begin to merge.

Spin-aligned black holes were likely sibling stars. Both would have been born from massive stars that evolved in close proximity in ancient star factories as a binary pair, eventually dying as supernovas.

But in this most recent event, the merging occurred relatively quickly and no additional oscillations were observed, meaning the two black holes were likely not spin-aligned and probably didn't form together. This gives a clue to their origin: Rather than being formed from sibling binary stars, they were strangers and evolved independently, drifting toward one another in the center of a dense stellar cluster where they eventually merged.

"This has implications for astrophysics ... while we cannot say with certainty, this finding likely favors the theory that these two black holes formed separately in a dense stellar cluster, sank to the core of the cluster and then paired up, rather than being formed together from the collapse of two already paired stars," adds Cadonati.

As black holes are gravitational monsters, they're governed by Einstein's general relativity, so by studying the gravitational waves they produce when they collide, scientists also can study the waves for an effect known as "dispersion." For example, when light travels through a prism, the different wavelengths will travel at different speeds through the glass. This causes dispersion in the beam of light — this is the mechanism that creates a rainbow.

General relativity forbids dispersion from happening to gravitational waves, however. This latest signal traveled across a record 3 billion light-years of spacetime to reach Earth, and LIGO didn't detect any dispersion effects.

"It looks like Einstein was right – even for this new event, which is about two times farther away than our first detection," says Cadonati in a statement. "We can see no deviation from the predictions of general relativity, and this greater distance helps us to make that statement with more confidence."

A New Window to the 'Dark Universe'

Einstein's famous theory of general relativity predicts the existence of gravitational waves, but it's taken humanity over a century to develop the technological know-how to build a detector sensitive enough to perceive them. When an energetic event occurs (like a black hole merger or neutron star collision), spacetime becomes violently disturbed and energy is carried away from the event in the form of gravitational waves — like ripples traveling across the water's surface after dropping a pebble in a pond.

But to detect these waves, astronomers need to build an observatory that can detect incredibly minuscule wobbles in the fabric of spacetime as these waves travel through our planet. Gravitational waves are not part of the electromagnetic spectrum; they cannot be detected by ordinary telescopes that are only sensitive to light.

To open the window to this "dark universe," physicists build gravitational wave detectors like LIGO that reflect incredibly precise lasers along 2.5 mile-long (4 kilometer-long) "L"-shaped tunnels. These tunnels are shielded from external vibrations caused by wind, traffic, tectonic activity and other terrestrial interference. Through a method known as laser interferometry, the distance between the reflecting mirrors inside the tunnel can be measured to a very high precision. Should a gravitational wave travel through our planet, a tiny change in distance may be recorded by the interferometer – this represents the minute squeezing and stretching of spacetime that occurs as gravitational waves propagate.

It's as if physicists have created a virtual tripwire that notifies us when an invisible gravitational wave intruder rumbles local spacetime.

One detector isn't enough to confirm a gravitational wave event, however. In the case of LIGO, one detector is located in Hanford, Washington, and another is located in Livingston, Louisiana — separated by 1,865 miles (3,002 kilometers). Only when the same event is detected by both locations can scientists confirm a gravitational wave signal. Two detectors can even determine a rough direction as to where the wave was traveling from, but if more detectors are added to the network, astronomers hope to eventually pinpoint, with increasing precision, where they originate.

More gravitational wave observatories are planned, and the European Virgo detector, located near Pisa, Italy, is currently undergoing commissioning. Once online, Virgo will be used in conjunction with LIGO to boost observational power of gravitational waves and allow better localization of the cosmic events causing the signals.

Now that the existence of gravitational waves has been confirmed, and astronomers are detecting more black hole mergers, we are entering a new era for astronomy. This is gravitational wave astronomy, where the dark universe will finally be revealed. </s> Astronomers have identified a star 9 billion light years from Earth – the farthest individual star ever seen.

Astronomers have identified a star 9 billion light years from Earth – the farthest individual star ever seen.

This achievement was made possible due to a phenomenon known as gravitational lensing. Previously used to locate planets far outside the Milky Way, lensing involves galaxies within astronomers’ line of sight bending rays of light and effectively magnifying objects in distant parts of the universe.

The team had been using the Hubble Space Telescope to monitor a supernova when they noticed a point of light, which they later realised was an individual star. In this case, the gravity of a massive galaxy cluster 5 billion light years away created the lensing effect, allowing astronomers to see the object – a blue supergiant they named Icarus.

“For the first time ever we’re seeing an individual normal star – not a supernova, not a gamma ray burst, but a single stable star – at a distance of 9 billion light years,” said Professor Alex Filippenko, an astronomer at the University of California, Berkeley, and a co-author of the paper documenting this discovery.

While it is possible to view galaxies very far away – as they glow with the light of billions of stars – and supernovas due to their incredible brightness, the discovery of an isolated star at this distance is unique. “You can see individual galaxies out there, but this star is at least 100 times farther away than the next individual star we can study,” said Dr Patrick Kelly, an astronomer at the University of Minnesota who led the study.

The reason for this discrepancy is that on top of the initial magnification by the galaxy cluster, this star was further magnified when another individual star within that cluster happened to precisely align in front of Icarus. This foreground star added to the overall magnification effect, boosting its brightness more than 2,000 times.

Dr Kelly and the team predict that in the coming decades Icarus will be magnified many more times, potentially as much as 10,000 times its actual brightness. They said by using gravitational lensing it could be possible to view many more distant objects, and in doing so learn about stars in galaxies formed during the first days of the universe.

“There are alignments like this all over the place as background stars or stars in lensing galaxies move around, offering the possibility of studying very distant stars dating from the early universe, just as we have been using gravitational lensing to study distant galaxies,” said Professor Filippenko. “For this type of research, nature has provided us with a larger telescope than we can possibly build.” </s> The Hubble Space Telescope has broken yet another observing record: The famed observatory has found the most distant "ordinary" star ever observed, at an astounding 9 billion light-years from Earth — which means the light scientists see started traveling at least 9 billion years ago. By comparison, the age of the universe is roughly 13.8 billion years.

Normally, stars that far away are too difficult to make out individually; a galaxy or a supernova (star explosion) is much easier to see. But this particular star — classified as an ordinary star, meaning a star on the main sequence of evolution that is fusing hydrogen into helium — came to light thanks to a rare alignment, researchers reported in a new study. When a main sequence star ceases burning the hydrogen at its core, it leaves the main sequence. This leads to a range of different outcomes for stars. Commonly, larger stars off the main sequence explode into supernovas, while smaller stars collapse into white dwarfs.

Astronomers found the star, which is nicknamed Icarus, through gravitational lensing. This phenomenon refers to how a massive galaxy cluster or other object can bend light from objects behind it, making dim objects much brighter from Earth's perspective. [In Photos: Cosmic Lenses Reveal Expansion of the Universe]

Usually, this lensing process can magnify objects by up to 50 times, but astronomers got lucky here: The newfound star was magnified more than 2,000 times because a star was briefly passing through the line of sight between Hubble and Icarus, researchers said in a statement from the University of California, Berkeley. This rare glimpse of a faraway star could provide a window into how stars in general evolve, especially those that are extremely luminous, the team said.

The most distant "normal" star ever found, nicknamed Icarus, was spotted 9 billion light-years from Earth because of a chance alignment with a foreground object. (Image credit: P. Kelly (University of California, Berkeley)/NASA/ESA)

"You can see individual galaxies out there, but this star is at least 100 times farther away than the next individual star we can study, except for supernova explosions," lead study author Patrick Kelly said in the statement. Kelly was a postdoctoral scholar at the University of California, Berkeley when he worked on the research but is currently on the faculty at the University of Minnesota.

Icarus, known more formally as MACS J1149 Lensed Star 1 (LS1), showed up as Kelly was following up on a supernova, called SN Refsdal, that he discovered in 2014. The supernova was discovered using a gravitational lens in the constellation Leo; the lens was formed by a galaxy cluster known as MACS J1149+2223.

"For the first time ever, we're seeing an individual normal star — not a supernova, not a gamma-ray burst, but a single stable star — at a distance of nine billion light-years," study co-author Alex Filippenko, an astronomer at UC Berkeley, said in the same statement. These lenses are amazing cosmic telescopes."

Kelly's team examined the colors coming from Icarus' light and found that it was a blue supergiant. This kind of star is more massive and larger than our sun, shining up to hundreds of thousands of times brighter. Still, Icarus was so far away that astronomers never would have spotted it without powerful lensing. Kelly suspected the star was far more magnified than the supernova — a hypothesis later borne out by modeling.

"By modeling the lens, they [astronomers] concluded that the tremendous apparent brightening of Icarus was probably caused by a unique effect of gravitational lensing," UC Berkeley representatives said in the statement. "While an extended lens, like a galaxy cluster, can only magnify a background object up to 50 times, smaller objects can magnify much more.

"A single star in a foreground lens, if precisely aligned with a background star, can magnify the background star thousands of times," they added. "In this case, a star about the size of our sun briefly passed directly through the line of sight between the distant star Icarus and Hubble, boosting its brightness more than 2,000 times."

The star Icarus appeared magnified by a factor of 2,000 because of an effect known as gravitational microlensing. (Image credit: NASA, ESA, S. Rodney (John Hopkins University) and the FrontierSN team; T. Treu (University of California, Los Angeles), P. Kelly (University of California, Berkeley) and the GLASS team; J. Lotz (STScI) and the Frontier Fields team; M. Postman (STScI) and)

Fortunately for astronomers, Icarus is well placed for more of these alignments. As stars in the cluster MACS J1149+2223 move around, the brightness of Icarus could be increased as much as 10,000 times during other lensing events. Astronomers might be able to catch more of these rare events in general if they look in the right location, the team added.

"There are alignments like this all over the place as background stars or stars in lensing galaxies move around, offering the possibility of studying very distant stars dating from the early universe, just as we have been using gravitational lensing to study distant galaxies," Filippenko said in the statement. "For this type of research, nature has provided us with a larger telescope than we can possibly build."

Icarus showed up in Hubble images taken between April 2016 and April 2017. A second star appeared in some observations that could be either a mirror image of Icarus or yet another star being gravitationally lensed.

Astronomers also probed dark matter — a little-understood substance that makes up most of the universe — with observations of Icarus. In contrast to what some previous theories had stated, the new observations suggest that dark matter is not made up of primordial black holes within galaxy clusters.

The new work was detailed today (April 2) in the journal Nature Astronomy.

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Astronomers detect light from 14 colliding galaxies. Due to the distances involved, the light comes from events which occurred around 12 billion years ago.