Gamma-ray bursts reveal largest structure in the universe is bigger and closer to Earth than we knew: 'The jury is still out on what it all means.'
When you buy through links on our articles, Future and its syndication partners may earn a commission.
The universe's largest structure, the Hercules-Corona Borealis Great Wall, was already a challenge to explain with models of the universe due to its incredibly vast size — and now, using the most powerful blasts of energy in the universe, Gamma-Ray Bursts (GRBs), astronomers have discovered this structure is even bigger than they realized. Plus, the team even found that parts of the Hercules-Corona Borealis Great Wall are actually closer to Earth than previously suspected.
The Hercules-Corona Borealis Great Wall is a so-called "supercluster" of galaxies; it's a filament of the cosmic web around which the first galaxies in the universe gathered and grew. Its name was coined by Johndric Valdez, a Filipino teenager who aspires to be an astronomer. That name isn't very literal, however. This is because the round-shaped Great Wall spans not just the constellations Hercules and Corona Borealis but also the region of the celestial sphere from the constellations Boötes to Gemini.
The Hercules-Corona Borealis Great Wall was first discovered in 2014 by a team led by István Horváth, Jon Hakkila and Zsolt Bagoly, who also led the team that has now determined the size of this structure more accurately than ever before. In particular, the team found that it extends over a larger radial range than previously calculated. Before this research, scientists didn't recognize that some nearby gamma-ray bursts are also part of this massive structure.
The finding is extraordinary because the Hercules-Corona Borealis Great Wall was already known to cover an area that's 10 billion light-years wide by 7.2 billion light-years and be almost 1 billion light-years thick! For context, that is large enough to fit over 94,000 Milky Way galaxies placed side by side along the Great Wall's longest side, which stretches out for around 10% of the total width of the entire observable universe.
"Since the most distant extent of the Hercules-Corona Borealis Great Wall is hard to verify, the most interesting finding is that the closest parts of it lie closer to us than had previously been identified," Jon Hakkila of the University of Alabama in Huntsville told Space.com.
The Milky Way, our home galaxy, is part of a different supercluster called Laniakea, which, at 500 million light-years wide, is dwarfed by the Hercules–Corona Borealis Great Wall. In fact, the team says the true extent of the latter structure is currently undetermined.
"Our gamma-ray burst sample is not large enough to place better upper limits on the maximum size of the Hercules-Corona Borealis Great Wall than we already have," Hakkila said. "But it probably extends farther than the 10 billion light-years we had previously identified. It is larger than the size of most anything to which it might be compared."
GRBs were key to the discovery of the Hercules-Corona Borealis Great Wall in 2014, and indeed to the recent, deeper investigation of this vast cosmic structure. Considered the most luminous and most energetic explosions in the universe, two different types of GRBs are thought to originate from two mechanisms of stellar-mass black hole formation, Hakkila explained.
Long-duration GRBs, which are blasts of high-energy gamma rays that last over two seconds, come from the core collapse of massive stars that leads to a supernova explosion. Short-duration GRBs, on the other hand, are thought to originate from the collision and merger of two ultradense stellar remnants called neutron stars in double-star systems.
"In both cases, the tremendous energies produced from the collapse of the star system are ejected in the form of relativistic particle jets. Far from a jet's nozzle, the particles react to produce gamma-rays and X-rays," Hakkila said. "Gamma-ray bursts can be seen at incredibly large distances because they are so luminous."
Hakkila says that because gamma-ray bursts are related to dying stars or the collision of two dead stars, and since stars are found in galaxies, gamma-ray bursts can act as measures of where galaxies are, too. Because of how bright they are, GRBs can indicate the presence of a galaxy even when that galaxy itself is too faint to be seen.
"The tremendous brightness of gamma-ray bursts allows them to be markers of where matter can be found in the universe," Hakkila said.
Part of the reason structures like the Hercules–Corona Borealis Great Wall are so perplexing to scientists has to do with the cosmological principle, which most models of the cosmos are founded upon.
The cosmological principle suggests the universe is homogeneous and isotropic on large scales, meaning it should look the same in all directions. Tracing the location of matter with GRBs, however, shows that this is not the case.
"It is surprising that gamma-ray bursts clustering is so much more pronounced in the northern galactic sky than in the southern galactic sky," Hakkila explained.
In their new paper, Hakkila and colleagues assert that, according to the cosmological principle, any cosmic structure larger than 1.2 billion light-years long shouldn't have had sufficient time in the 13.8 billion-year-old universe to form if the spread of matter is homogeneous and isotropic.
So, as a vast 10 billion light-year structure of galaxies located around 10 billion light-years away (as indicated by dense GRBs clustering toward the northwestern region of the celestial sphere over Earth_ the Hercules–Corona Borealis Great Wall definitely challenges the cosmological principle.
"Some theoretical cosmological models can account for structures this large, while others cannot," Hakkila added. "The jury is still out on what it all means."
The team reached their new hint at the size of the Hercules–Corona Borealis Great Wall using a database of 542 GRBs resulting from observations collected up until 2018, predominantly by NASA's Fermi Gamma-ray Space Telescope and the Neil Gehrels Swift Observatory.
Gamma-ray bursts are useful measurement tools in cosmology — with a few caveats. The main one is that it takes the observation of a tremendously large number of GRBs to draw meaningful conclusions about their distribution.
Additionally, if scientists want to draw accurate conclusions about the structure of the universe, misidentification of GRB origin positions in space must be eliminated. Thus, it may take a long time before scientists can use GRBs to gather a better picture of the Hercules–Corona Borealis Great Wall.
"It has taken years of observation to collect a sample this large, using data mainly from Fermi and Swift, which have been instrumental in building this unprecedented dataset," Hakkila said. "Assembling a sample of this size took more than 20 years of observations, and we do not anticipate significant additions in the near future."
Related Stories:
— 'Mind-blowing' dark energy instrument results show Einstein was right about gravity — again
— Dark energy is even stranger than we thought, new 3D map of the universe suggests. 'What a time to be alive!' (video)
— Dark energy could be getting weaker, suggesting the universe will end in a 'Big Crunch'
Moving forward, the team intends to continue analyzing the properties of the GRBs in the sample used for this research.
"We probably need to study it more carefully and in greater detail than has been done before," Hakkila explained. "Looking ahead, new missions will be essential to overcome current limitations. We are actively contributing to the development of THESEUS, a proposed ESA mission designed to revolutionize GRB studies."
With its unparalleled sensitivity and sky coverage, Hakkila said that THESEUS, or the "Transient High Energy Sources and Early Universe Surveyor," is expected to dramatically increase the number of known GRBs, particularly at great cosmic distances or high redshifts.
"This could finally provide the observational leverage needed to map the Hercules–Corona Borealis Great Wall in its full extent, offering a breakthrough in understanding large-scale structure formation and the cosmic web," Hakkila said.
A pre-peer-reviewed version of the team's research appears on the paper repository site arXiv.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Yahoo
5 hours ago
- Yahoo
'We've got a new mystery on our hands': Titan's weird wobble just got even stranger
When you buy through links on our articles, Future and its syndication partners may earn a commission. For years, scientists have been intrigued by a weird "wobble" in the atmosphere of Titan, Saturn's largest moon. Now, new research is revealing clues about Titan's strange atmospheric tilt, but it's also raising new mysteries. Data from the Cassini mission to Saturn has shown that, unlike Earth's atmosphere, Titan's atmosphere doesn't rotate in sync with its surface. Instead, it tilts and shifts like a spinning top that changes its orientation with the seasons. "The behaviour of Titan's atmospheric tilt is very strange," Lucy Wright, lead author of the new research and a postdoctoral researcher in the School of Earth Sciences at the University of Bristol in the U.K., said in a statement. "We think some event in the past may have knocked the atmosphere off its spin axis, causing it to wobble." Scientists thought the direction of the tilt would be influenced by either Saturn's gravity or the position of the sun, as is often the case in planetary systems — meaning it would change as Titan orbited Saturn and the sun. But observations show that the tilt direction doesn't move. Instead, it stays pointed the same way in space, as if unaffected by those external forces. This finding was unexpected. If solar heating or Saturn's gravity were controlling the tilt, it should move over time. Instead, the tilt seems locked in place, suggesting that some other, still-unknown process is at work, the researchers reported in a study published May 20 in The Planetary Science Journal. "That would've given us clues to the cause," Nick Teanby, co-author of the study and a planetary scientist at the University of Bristol, said in the statement. "Instead, we've got a new mystery on our hands." Titan is the only moon in the solar system known to have a substantial atmosphere. It is composed primarily of nitrogen and contains complex organic molecules, making it a scientifically important object for studying things like atmospheric processes and prebiotic chemistry. RELATED STORIES —Saturn's moon Titan may have a 6-mile-thick crust of methane ice — could life be under there? —There's liquid on Titan, Saturn's largest moon. But something's missing and scientists are confused —Alien life could exist on Saturn's big moon Titan — but finding it will be tough From 2004 to 2017, NASA's Cassini spacecraft closely observed Titan, revealing important changes in its atmosphere, like a steady tilt in the middle layers and the appearance and disappearance of swirling winter polar vortices. This new understanding of Titan's atmospheric wobble is important for NASA's upcoming Dragonfly mission, which is set to arrive in the 2030s. Because Titan's winds are much faster than its surface rotation, knowing how the atmosphere shifts with the seasons will help engineers more accurately plan Dragonfly's descent and landing. "Our work shows that there are still remarkable discoveries to be made in Cassini's archive," study co-author Conor Nixon, a planetary scientist at NASA's Goddard Space Flight Center, said in the statement. "This instrument, partly built in the U.K., journeyed across the Solar System and continues to give us valuable scientific returns. "The fact that Titan's atmosphere behaves like a spinning top disconnected from its surface raises fascinating questions — not just for Titan, but for understanding atmospheric physics more broadly, including on Earth," Nixon added.
Yahoo
5 hours ago
- Yahoo
Haunting blood-red squid with large hooks drifts through Antarctic ocean's midnight zone in world-first video
When you buy through links on our articles, Future and its syndication partners may earn a commission. An elusive species of deep-sea squid has been seen alive for the first time off Antarctica, National Geographic has announced. Researchers filmed the Antarctic gonate squid (Gonatus antarcticus) drifting through the black waters of the ocean's midnight zone, 7,060 feet (2,152 meters) below the surface, on Dec. 25, 2024. As first reported by National Geographic, researchers spotted the 3-foot-long (0.9 m) blood-red creature using a remotely operated vehicle (ROV), which had been deployed from the Schmidt Ocean Institute's research vessel, the R/V Falkor (too). They sent the footage to Kat Bolstad, head of the Lab for Cephalopod Ecology and Systematics at Auckland University of Technology in New Zealand, who confirmed it was an Antarctic gonate squid. "This is, to the best of my knowledge, the first live footage of this animal worldwide," Bolstad told National Geographic. Related: Elusive colossal squid finally caught on camera 100 years after discovery in world 1st footage — and it's tiny Scientists have known about the Antarctic gonate squid for more than 100 years, but they have previously only seen dead specimens caught in fishing nets or beaks that had been preserved in the stomachs of other animals. This is the first time scientists have observed the squid alive and in its natural habitat. The creature was in the bathypelagic or midnight zone, 3,300 to 13,100 feet (1,000 to 4,000 m) below the ocean's surface. No sunlight can penetrate that far into the ocean, so the midnight zone's only light comes from animals that can illuminate themselves with bioluminescence, according to the National Oceanic and Atmospheric Administration (NOAA). RELATED STORIES —Watch extremely rare footage of a bigfin squid 'walking' on long, spindly arms deep in the South Pacific —Rare video shows elusive deep-sea squid cradling her gigantic, translucent eggs —Elusive 'octopus squid' with world's largest biological lights attacks camera in striking new video The squid released a cloud of greenish ink when the ROV approached, potentially startled by the presence of a large, bright vehicle in its environment. The researchers followed the animal for a few minutes, using the ROV's lasers to measure its size, before the squid shot away into the darkness, National Geographic reported. While researchers couldn't determine the sex or age of the animal, Bolstad confirmed it was an Antarctic gonate squid by observing the presence of a single, large hook on the ends of its two longer tentacles. "The impressive tentacle hooks are probably used for grasping and subduing prey during ambush predation," Alex Hayward, a senior lecturer in ecology and conservation at the University of Exeter in England who was not involved in the expedition, told National Geographic.
Yahoo
5 hours ago
- Yahoo
Coating satellites with super-dark Vantablack paint could help fight light pollution crisis
When you buy through links on our articles, Future and its syndication partners may earn a commission. A new type of super-black, highly resistant satellite paint promises an affordable fix to the satellite light pollution problem that has marred astronomical research since the recent advent of low-Earth-orbit megaconstellations. One of these, the internet-beaming Starlink constellation, has been a matter of controversy since the launch of the first batch of its satellites in 2019. The constellation's thousands of spacecraft orbit so low that the sunlight they reflect outshines many stars from our perspective on Earth. And while the sight of a Starlink satellite train might thrill skywatchers, it's a true nightmare to astronomers worldwide. When the $1.9 billion Vera Rubin Observatory opens its telescopic eyes to the sky later this month, astronomers expect that up to 40% of its images will be degraded or completely ruined by satellite streaks. It's a costly problem that will only become more serious as the number of satellites in orbit is expected to grow to tens of thousands within the next few years. But a new paint being developed in conjunction with astronomers might help. The paint, called Vantablack 310, could reduce the amount of light reflected by satellites in orbit down to just 2% of what is reflected by uncoated satellites, virtually erasing the pesky streaks from telescope images. According to Noelia Noël, an astrophysicist at the University of Surrey, these satellite streaks will significantly reduce the scientific return on investment that the taxpayer-funded Vera Rubin telescope represents. Noël, who is expected to take part in Rubin's ten-year mission to map the sky in unprecedented detail, has been concerned about the loss of the pristine dark sky for years. A native of Argentina, Noël grew up in awe of the star-studded southern sky and has been painfully aware of its deterioration. Those concerns led her to establishing a partnership with a University of Surrey spin-off, Surrey NanoSystems, who has been developing ultra black coatings for scientific instruments on satellites. The partnership has now produced a new type of blacker-than-black space paint, which reflects less light than available alternatives and can be easily applied by satellite makers in their clean rooms. "Over the past five years, humankind has launched more satellites into space than it has done over the previous 60 years," Noël told "It's a real problem for astronomy, especially for telescopes like Vera Rubin, which had to significantly change its observing strategy to avoid satellite clusters. So, I wanted to do something about it." Surrey NanoSystems' previous coatings, although exquisite at reflecting light (the flagship Vantablack High Performance coating absorbs 99.9% of incoming sunrays), were based on delicate nanotechnology that required a technically complicated application process. Once applied, the coating couldn't be touched by a human hand or it would lose its anti-reflective properties. "The previous coating was based on a carbon nanotube structure that can't be touched because it would collapse," Kieran Clifford, a materials scientist at Surrey NanoSystems, told "We needed something that can be easily handled by engineers at their own facilities." The new coating is based on a proprietary blend of carbon black, a soot-like form of carbon, mixed with special binders that make the paint resistant against the harsh conditions in near-Earth space. In tests, the new coating outperformed other similar paints currently on the market not just in terms of its light absorption ability but also durability in space, Clifford said. "We conducted tests that simulated three years in orbit and our coating withstood it with negligible changes whereas other types of space paints completely eroded," said Clifford. "Our coating also offers a better optical performance. Where competitor coatings reflect about 5% of the incoming light, the Vantablack 310 coating only reflects 2% of the light across the visible and near infrared spectrum." SpaceX has previously experimented with dark paint to reduce the brightness of its satellites, but those experiments provided mixed results. In some cases, the satellites began to overheat due to the amount of absorbed light. The new paint should not cause such problems, Clifford believes, and will make the satellites much less visible than the current Starlinks. "We know from some simulations that we have done that our coating should make satellites invisible to the naked eye," Clifford said. "That's about magnitude 7 in terms of brightness while Starlink satellites range from magnitude 3 to magnitude 5." Magnitude is a measure of luminosity of astronomical objects, which is inverse to the object's actual brightness. The lower the magnitude number, the brighter the object is. The magnitude scale is logarithmic, meaning the observed brightness increases exponentially with the decreasing magnitude number. Surrey NanoSystems and the University of Surrey will test the Vantablack 310 coating in space on the student satellite Jovian 1, which will carry a range of payloads built by British universities to low Earth orbit next year. "The rear of the satellite's deployable solar panel will be coated with Vantablack 310, and we will be rotating the satellite while making ground-based measurements to observe the changes in brightness," Clifford said. The company is already in talks with satellite manufacturers. They hope that the ease of the paint's application, its exquisite durability and ability to reduce brightness will inspire them to use it on their satellites in the future. "I don't want to be too optimistic, but I hope that with this new solution, we might be able to inspire some policy changes," Noël said. "Satellites are an amazing technology, but we also want to make sure that the sky remains accessible to everyone. Large telescopes represent a huge investment, and we want to make sure that it doesn't go to waste."
