News Feeds

Physicists have proposed a solution to a long-standing puzzle surrounding the GD-1 stellar stream, one of the most well-studied streams within the galactic halo of the Milky Way.

A formula can be used to predict what happens when a new species is introduced into an ecosystem -- whether it will establish itself in the community or fail to gain a foothold and die out.

I’ve used this fact a gazillion times; every atom in your body has been through the core of a star! The carbon in our bones formed through fusion like many other elements and was thrown out into space to seed the cosmos with the elements for life. A team of researchers have been exploring this journey, tracking a giant conveyor belt that surrounds the Galaxy and the results are surprising. 

Carbon is one of the fundamental elements inside our bodies. The first elements that appeared after the Universe formed 13.7 billion years ago was mostly hydrogen and a little helium.  The carbon in our bodies has been synthesised inside stars in a process known as nucleosynthesis. 

As stars evolve, they undergo a series of fusion reactions fusing hydrogen atoms into helium, then helium nuclei into carbon. Three helium-4 atoms combine to create an atom of carbon-12. Temperatures of around 100 million kelvin are needed for this process and, as it progresses, an outward pushing force known as the thermonuclear force is generated. During the main part of a stars life, this is balanced by the inward force of gravity. 

This is an artist’s concept of the early stages of the young star FU Orionis (FU Ori) outburst, surrounded by a disk of material. A team of astronomers has used the Hubble Space Telescope’s ultraviolet capabilities to learn more about the interaction between FU Ori’s stellar surface and the accretion disk that has been dumping gas onto the growing star for nearly 90 years. NASA-JPL, Caltech

At a point in the evolution of the star which is determined by its mass, the material that composes the star is ejected out into space through a planetary nebula or supernova explosion. Ultimately these heavier elements find their way to new stellar nurseries where the next generation of stars and even planets and life may form. 

This colorful web of wispy gas filaments is the Vela Supernova Remnant, an expanding nebula of cosmic debris left over from a massive star that exploded about 11,000 years ago. This image was taken with the Department of Energy-fabricated Dark Energy Camera (DECam), mounted on the US National Science Foundation’s Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF’s NOIRLab. The striking reds, yellows, and blues in this image were achieved through the use of three DECam filters that each collect a specific color of light. Separate images were taken in each filter and then stacked on top of each other to produce this high-resolution image that contains 1.3 gigapixels and showcases the intricate web-like filaments snaking throughout the expanding cloud of gas.

Scientists from the United States and Canada have shown in their latest research that the liberated carbon atoms don’t just drift aimlessly through space until they find their new home. Instead, their studies reveal that in galaxies like the Milky Way where star formation is still underway, the atoms take a less direct route. Giant currents known as the circumgalactic medium circle the galaxy and extend out into intergalactic space. The currents drag the newly ejected stellar material out and draw it back in to the interior of the galaxy where it forms new stars. 

The Milky Way. This image is constructed from data from the ESA’s Gaia mission that’s mapping over one billion of the galaxy’s stars. Image Credit: ESA/Gaia/DPAC

To reach this conclusion, the team used the Cosmic Origins Spectrograph on the Hubble Space Telescope. This instrument enabled the study of the ultraviolet radiation in detail from nine distant quasars. They explored how they were effected by circumgalactic medium of 11 other galaxies that had active star forming regions. The results showed the absorption of light by carbon. One galaxy showed carbon caught up in the current extending to a distance of nearly 400,000 light years. To put that into context that is around four times the diameter of our own Milky Way Galaxy! 

This image of NASA’s Hubble Space Telescope was taken on May 19, 2009 after deployment during Servicing Mission 4. NASA

It’s quite an eye opening discovery and certainly repaints the picture of stellar evolution. Instead of the gentle drifting through space of elements ejected from stars, the journey is far more tumultuous. As always though, more research is needed to fully understand the circumgalactic medium and to understand its impact on stellar formation. Not only will we get a better understanding of the lives of stars but how galaxies evolve too and why some host active star formation and others are stellar deserts. 

Source : The carbon in our bodies probably left the galaxy and came back on cosmic ‘conveyer belt’

The post You’re Made of Carbon that Took a Journey into Intergalactic Space appeared first on Universe Today.

A person in Louisiana who became severely ill with a bird flu virus known as H5N1 in December has passed away from the infection, marking the first known bird flu death in the US

Nature is filled with examples of extreme life (aka. extremophiles), which are so-called because they can withstand extreme conditions. These include organisms that can survive in extremely dry conditions, extreme temperatures, acidity, pressure, and even the vacuum of space. The study of these organisms not only helps scientists learn more about the kinds of environments life can survive (and even thrive) in. It also helps astrobiologists to speculate about possible life in the Universe. Perhaps the name “tardigrades” (aka. “water bears”) rings a bell, those little creatures that could survive in interstellar space?

Then you have Deinococcus radiodurans (D. radiodurans), which microbiologists call “Conan the Bacterium” due to its ability to tolerate the harshest conditions. This includes radiation doses thousands of times higher than what would kill a human, or any other organism on Earth, for that matter. In a new study, a team of researchers from Northwestern University and the Uniformed Services University (USU) characterized a synthetic organism inspired by Deinococcus radiodurans that could allow humans to withstand the elevated radiation levels in deep space, on the Moon, and Mars.

The research was led by Hao Yang, a Research Assistant Professor at Northwestern University’s Department of Chemistry. He was joined by Ajay Sharma, also a Research Assistant Professor of Chemistry at Northwestern; Michael J. Daly, a Professor of Pathology at the Uniformed Services University (USU); and Brian M. Hoffman, the Charles E. and Emma H. Morrison Professor of Chemistry and molecular biosciences at Northwestern. The paper detailing their findings appeared on November 8th in the Proceedings of the National Academy of Sciences (PNAS).

Image of the Martian atmosphere and surface obtained by the Viking 1 orbiter in June 1976. (Credit: NASA/Viking 1)

Hoffman is the Charles E. and Emma H. Morrison Professor of Chemistry and professor of molecular biosciences and a member of the Chemistry of Life Processes Institute and the Robert H. Lurie Comprehensive Cancer Center at Northwestern University. Daly, an expert on Deinococcus radiodurans, is also a member of the National Academies’ Committee on Planetary Protection. In a previous study, Hoffman and Daly investigated D. radiodurans‘ ability to withstand radiation on Mars. Earlier research has shown that the bacterium can survive 25,000 grays, which is five times the lethal dose for a human.

However, Hoffman and Daly found that D. radiodurans could withstand 140,000 grays when dried or frozen – 28,000 times the lethal dose for a human! This means that frozen microbes beneath the surface of Mars could survive the cosmic and solar radiation the planet is exposed to on a daily basis. The key to its resistance, they determined, is simple metabolites that combine with manganese to form a powerful antioxidant. They also found that the radiation dose a microorganism can survive is directly related to the amount of manganese antioxidants it contains.

In this latest study, the research team describes a synthetic designer antioxidant (MDP) inspired by D. radiodurans that is much more effective at resisting radiation. Building on their previous efforts, Hoffman and Daly’s team investigated a designer decapeptide (DP1) that, when combined with phosphate and manganese, forms the free-radical-scavenging agent MDP, which is even better at protecting against radiation damage than D. radiodurans. As Hoffman explained in a Northwestern Now news release:

“It is this ternary complex that is MDP’s superb shield against the effects of radiation. We’ve long known that manganese ions and phosphate together make a strong antioxidant, but discovering and understanding the ‘magic’ potency provided by the addition of the third component is a breakthrough. This study has provided the key to understanding why this combination is such a powerful — and promising — radioprotectant.”

An artist’s concept of Mars explorers and their habitat on the Red Planet. Courtesy NASA

“This new understanding of MDP could lead to the development of even more potent manganese-based antioxidants for applications in health care, industry, defense, and space exploration,” said Daly. Potential applications include synthetic antioxidants that could help protect astronauts from radiation during long-duration missions to deep space. In another study, Daly and his collaborators found MDP is effective in preparing irradiated polyvalent vaccines. This could also have applications for space medicine, ensuring that vaccines typically rendered inactive by radiation remain effective.

Further Reading: Northwestern Now, PNAS

The post This Superbacteria can Withstand Enough Radiation to Kill a Person appeared first on Universe Today.

In the last couple of decades, it’s become increasingly clear that massive galaxies like our own Milky Way host supermassive black holes (SMBHs) in their centres. How they became so massive and how they affect their surroundings are active questions in astronomy. Astronomers working with the James Webb Space Telescope have discovered an SMBH in the early Universe that is accreting mass at a very low rate, even though the black hole is extremely massive compared to its host galaxy.

What’s going on with this SMBH, and what does it tell astronomers about the growth of these gargantuan black holes?

The black hole, named GN-1001830, was discovered as part of JADES (JWST Advanced Deep Extragalactic Survey). It is one of the most massive SMBHs discovered by the JWST in the early Universe. While most present-day SMBHs account for about 0.1 % of the mass of their host galaxies, this one accounts for about 40% of its host galaxy’s mass.

The puzzling thing is that GN-1001830 is consuming the gas it needs to grow at a very low rate and is basically dormant. Is it taking a break? Did it experience accelerated bursts of growth in the past?

The findings are in new research published in Nature titled “A dormant overmassive black hole in the early Universe.” The lead author is Ignas Juodžbalis. Juodžbalis is a grad student at the Kavli Institute for Cosmology at the University of Cambridge.

“The early universe managed to produce some absolute monsters, even in relatively tiny galaxies.”

Ignas Juodžbalis, Kavli Institute for Cosmology, University of Cambridge

The JWST has found many SMBHs already in place, only a few hundred million years after the Big Bang. Some of them are overmassive yet dormant, like GN-1001830. Researchers have developed multiple different models to explain them.

This image shows the JWST Advanced Deep Extragalactic Survey (JADES) region of study. It’s in the same region as the Hubble’s Ultra Deep Field. Image Credit:

One model is the ‘heavy seed‘ model, where primordial gas clouds directly collapsed into black holes that grew to become SMBHs. Another model proposes light seeds that experience powerful bursts of accretion. Both models hold promise, but there’s no certainty. “Yet, current datasets are unable to differentiate between these various scenarios,” Juodžbalis and his co-authors write in their research article.

These overmassive black holes that appear to be dormant are testing astrophysicists’ understanding of how SMBHs form and grow. It’s likely that they go through bursts of growth, and in between those bursts, they lie dormant. One of the problems is that it’s very difficult to spot an SMBH that isn’t actively accreting gas. They’re visible when accreting because the accretion disk heats up and emits light.

This one was only spotted because it’s so massive.

“Even though this black hole is dormant, its enormous size made it possible for us to detect,” said lead author Juodžbalis. “Its dormant state allowed us to learn about the mass of the host galaxy as well. The early universe managed to produce some absolute monsters, even in relatively tiny galaxies.”

The Eddington Limit (also known as Eddington Luminosity) is an important factor in the growth of SMBHs. It is a theoretical upper limit on the mass and luminosity of stellar objects, explaining the luminosity we observe in accreting black holes. The Eddington limit is reached when the outward pressure of radiation exceeds the object’s gravitational power, and it can’t accrete more matter. Objects can also exceed this limit, and when that happens, it’s called Super Eddington accretion. Some researchers suggest that Super Eddington accretion was more common in the early Universe and that it explains not only this overmassive black hole but all of the other massive black holes the JWST has discovered in the Universe’s early times.

“It’s possible that black holes are ‘born big’, which could explain why Webb has spotted huge black holes in the early universe,” said co-author Professor Roberto Maiolino from the Kavli Institute and Cambridge’s Cavendish Laboratory. “But another possibility is they go through periods of hyperactivity, followed by long periods of dormancy.”

“It’s likely that the vast majority of black holes out there are in this dormant state.”

Professor Roberto Maiolino, Kavli Institute and Cambridge’s Cavendish Laboratory

The research is based on the detection of broad H-alpha emissions from the SMBH. Those emissions showed that the overmassive black hole has an estimated mass of approximately 4 × 10? (40 million) solar masses. That’s extremely massive for an object only about 800 million years after the Big Bang. For comparison, Sagittarius A*, the SMBH in the Milky Way, has an estimated mass of about 4.3 million solar masses.

The SMBH in question is one of the most overmassive objects the JWST has found. Its mass is almost 50% of the stellar mass of its host galaxy. That’s about 1,000 times more massive than the relation in local galaxies.

The researchers conducted computer simulations to probe the issue. Their research suggests that the SMBH’s periods of hyperactivity likely exceed the Eddington Limit. The SMBH’s long periods of dormancy and inactivity can last for 100 million years, where the accretion rate is only 0.02 times the Eddington Limit, and are punctuated by episodes of Super Eddington accretion that last for about five or ten million years.

“It sounds counterintuitive to explain a dormant black hole with periods of hyperactivity, but these short bursts allow it to grow quickly while spending most of its time napping,” said Maiolino.

Since these SMBHs spend far more time dormant than they do active, they’re more likely to be spotted during dormancy. However, they’re far more difficult to spot when they’re not actively accreting and emitting radiation from their accretion rings. That’s part of what makes this detection so valuable.

These results are agnostic when it comes to heavy or light seeds. Instead, they’re all about Super Eddington episodes. “It is tempting to speculate that our result favours light seed models. However, the same result would also hold if the models had started with heavy seeds. The key feature that allows the properties of GN-1001830 to be matched is the fact that accretion goes through super-Eddington phases, regardless of the seeding mechanism,” the authors explain.

This set of illustrations explains how a large black hole can form from the direct collapse of a massive cloud of gas a few hundred million years after the Big Bang. Panel #1 shows a massive gas cloud and a galaxy moving towards each other. If the formation of stars in the gas cloud is stalled by radiation from the incoming galaxy – preventing it from forming a new galaxy — the gas can instead be driven to collapse and form a disk and black hole. Panels #2 and #3 show the beginning of this gas collapse in the center of the cloud. A small black hole forms in the center of the disk (panel #4), and the black hole and disk then continue to grow (panel #5). This massive black hole “seed” and its disk then merge with the galaxy shown in panel #1. For a period of time, the black hole is unusually massive compared to the mass of the stars in the galaxy, making it an Overmassive Black Hole (panel #6). Stars and gas from the galaxy are pulled in by the black hole, causing the black hole and disk to grow even larger. Image Credit: NASA/STScI/Lea Hustak

“This was the first result I had as part of my PhD, and it took me a little while to appreciate just how remarkable it was,” said Juodžbalis. “It wasn’t until I started speaking with my colleagues on the theoretical side of astronomy that I was able to see the true significance of this black hole.”

“It’s likely that the vast majority of black holes out there are in this dormant state—I’m surprised we found this one—but I’m excited to think that there are so many more we could find,” said Maiolino.

The post An Early Supermassive Black Hole Took a Little Break Between Feasts appeared first on Universe Today.

Wastewater treatment plants in the US may discharge enough “forever chemicals” to raise concentrations in drinking water above the safe limit for millions of people

Lead records from Arctic glaciers indicate that people all over Europe would have been affected by pollution from metal smelting during the Roman era

Scientists have developed an advanced swarm navigation algorithm for cyborg insects that prevents them from becoming stuck while navigating challenging terrain. The new algorithm represents a significant advance in swarm robotics. It could pave the way for applications in disaster relief, search-and-rescue missions, and infrastructure inspection. Cyborg insects are real insects equipped with tiny electronic devices on their backs -- consisting of various sensors like optical and infrared cameras, a battery, and an antenna for communication -- that allow their movements to be remotely controlled for specific tasks.

Scientists have developed an advanced swarm navigation algorithm for cyborg insects that prevents them from becoming stuck while navigating challenging terrain. The new algorithm represents a significant advance in swarm robotics. It could pave the way for applications in disaster relief, search-and-rescue missions, and infrastructure inspection. Cyborg insects are real insects equipped with tiny electronic devices on their backs -- consisting of various sensors like optical and infrared cameras, a battery, and an antenna for communication -- that allow their movements to be remotely controlled for specific tasks.

Among the hundreds of thousands of chemical compounds produced by plants, some may hold the key to treating human ailments and diseases. But recreating these complex, naturally occurring molecules in the lab often requires a time-consuming and tedious trial-and-error process. Now, chemists have shown how new computational tools can help them create complex natural compounds in a faster and more streamlined way.

A recent study highlights a groundbreaking development in foldable molecular paths within solid-state frameworks, illuminating their potential for dynamic pore control and transformative applications in molecular metamaterials.

Collaborative work by amateur and professional astronomers has helped to resolve a long-standing misunderstanding about the composition of Jupiter's clouds. Instead of being formed of ammonia ice -- the conventional view -- it now appears they are likely to be composed of ammonium hydrosulphide mixed with smog.

Engineers have utilized quantum sensors to realize a groundbreaking variation of nuclear quadrupolar resonance (NQR) spectroscopy, a technique traditionally used to detect drugs and explosives or analyze pharmaceuticals. The new method is so precise that it can detect the NQR signals from individual atoms -- a feat once thought unattainable. This unprecedented sensitivity opens the door to breakthroughs in fields like drug development, where understanding molecular interactions at the atomic level is critical.

Engineers have utilized quantum sensors to realize a groundbreaking variation of nuclear quadrupolar resonance (NQR) spectroscopy, a technique traditionally used to detect drugs and explosives or analyze pharmaceuticals. The new method is so precise that it can detect the NQR signals from individual atoms -- a feat once thought unattainable. This unprecedented sensitivity opens the door to breakthroughs in fields like drug development, where understanding molecular interactions at the atomic level is critical.

Researchers have developed a way of detecting circulating tumor cells in the bloodstream of pancreatic cancer and lung cancer patients.

Comet C/2024 G3 ATLAS may put on a quick show this month.

Comet G3 ATLAS on December 30th. Credit: Alan C. Tough

What ‘may’ be the best anticipated comet of 2025 is coming right up. Right now, there’s only one comet with real potential to reach naked eye visibility in 2025: Comet C/2024 G3 ATLAS. This comet reaches perihelion at 0.094 Astronomical Units (AU, 8.7 million miles or 14 million kilometers, interior to the orbit of Mercury) from the Sun on January 13th, and ‘may’ top -1st magnitude or brighter. At magnitude +4 in late December, Comet G3 ATLAS could become a fine object low in the dawn sky for southern hemisphere observers… if (a big ‘if) it holds together and performs as expected.

The comet actually produced an outburst over the first weekend of 2025, jumping from magnitude +4 to +1 (a sixteen-fold increase in brightness in a few short days). This could be a harbinger for good (or bad) things to come shortly.

“The comet has had an outburst in the last few days,” Nicolas Lefaudeux told Universe Today. “If the outburst is linked to disintegration, there would probably be nothing to see after perihelion. If the outburst is linked to new active areas or splitting of a large nucleus, the display could be much better than in the simulations.”

The prospects for the tail of Comet G3 ATLAS, around perihelion. Credit: Nicolas Lefaudeux

A recent International Astronomical Union Central Bureau for Astronomical Telegrams message suggests an optimistic peak of -3rd magnitude near perihelion post outburst, ‘if’ the comet holds together.

Comet G3 ATLAS low at dawn versus Mercury on January 11th. Credit: Starry Night. The Discovery

The comet was discovered by the Asteroid Terrestrial-Impact Last Alert System (ATLAS) survey as a +19th magnitude object in the southern hemisphere constellation Apus the Bee on the night of April 5th, 2024.

The orbital path for Comet G3 ATLAS through the inner solar system. Credit: NASA/JPL

The orbital period for this one is around 160,000 years. It’s unclear if Comet G3 ATLAS is a first-time visitor to the inner solar system, or a new denizen coming from the distant Oort Cloud. The last time the comet swung by the inner solar system (assuming it has done so in the past), wearing clothing was the hot new thing among our homo sapiens ancestors.

Comet G3 ATLAS from January 2nd. Credit: iTelescope/Tara Prystavski. Comet G3 at Perihelion: Perish or Prosper?

Prospects for seeing this comet will be tricky. Unlike last year’s Comet C/2023 A3 Tsuchinshan-ATLAS which unfurled a magnificent tail for its evening apparition, G3 ATLAS will be a timid one both before and after perihelion, as it departs our solar neighborhood hugging the southern horizon in the dusk sky.

Comet G3 ATLAS, post perihelion on January 15th at dusk. Credit: Starry Night.

A daytime comet could be in the offing if G3 ATLAS over-performs at perihelion… but it will be a challenging view, very near the Sun. Be sure to block the dangerous glare of the Sun fully out of view behind a building or structure if you attempt to spot the comet in daylight. Like A3 T-ATLAS, the joint NASA/ESA SOHO observatory will see the comet near perihelion crossing through its LASCO C3 viewer.

Comet G3 ATLAS versus SOHO through the month of January. Credit: Starry Night. Best Bets For Comet G3 ATLAS

Perihelion on Monday, January 13th, 2025 will see the comet just four degrees from the Sun. The comet also makes its closest approach to Earth at 0.938 AU distant on the same date. The comet ‘could’ reach -4th magnitude (about as bright as Venus) around the same time… if it manages to hold together at perihelion.

Here’s a recent remote telescope image of the comet taken from late December by Nick James:

Comet G3 ATLAS from December 15th. Credit: Nick James/BAA Comet Section/iTelescope.

Comet G3 ATLAS has been elusive thus far. The comet has been bashful, skimming just five degrees above the dawn horizon leading up to perihelion in early January for northern hemisphere observers. The comet reemerges low to the west after dusk, but again, folks up north only get a very brief view 5-10 degrees above the horizon at dusk, as the comet runs parallel with the horizon southward. As usually seems to be the case with comets, the southern hemisphere gets the better view.

Here’s a blow-by-blow of what to expect in the coming months from the comet. (Note that ‘passes near,’ denotes a conjunction of a degree or less):

January

6-Near the Lagoon Nebula (Messier 8)

7-Near the globular cluster (Messier 28)

8-Crosses the ecliptic plane northward

11-Enters SOHO LASCO C3 view

13-At perihelion, less than 5 degrees from the Sun

14-Crosses into the constellation Capricornus

15-Exits SOHO LASCO C3 view, and crosses the ecliptic plane southward

21-Nicks the corner of the constellation Microscopium

22-Crosses into the constellation Piscis Austrinus

The light curve for comet G3 ATLAS. Adapted from Seichii Yoshida’s Weekly Information About Bright Comets. February

1-May drop back down below +6th magnitude

6-Crosses into the constellation Grus

21-Nicks the corner of the constellation Sculptor

25-Crosses into the constellation Phoenix

March

March 1st: May drop back down below +10th magnitude.

Observing and imaging the comet will be challenging, owing to two main factors: first, it will never really leave the low-contrast, twilight sky for northern hemisphere observers. Second, said quoted magnitude for a comet gets ‘smeared out’ over its apparent surface area, knocking the comet’s apparent brightness down a notch or two. We can hope that Comet G3 ATLAS is an over-performer in this regard. My strategy is to find high ground to observe from and the lowest, flattest horizon (like, say, the ocean as seen from a beach) that you can find, and sweep the horizon at low power with binoculars for the fuzzball of a comet.

Good luck and clear skies on this, the first comet quest of 2025.

The post Will Comet G3 ATLAS Perform at Perihelion? appeared first on Universe Today.

Throat vibrations made by people who find it difficult to speak, such as after a stroke, can be analysed by AI and used to create sentences

One powerful way to study the galaxies is to study individual stars. By looking at the ages, types, and distribution of stars in the Milky Way, we’ve captured a detailed snapshot of how our galaxy formed and evolved. The only problem with this approach is that we can only do this for a handful of galaxies. Even with the most powerful telescopes, we can only see individual stars in the Milky Way and nearby galaxies such as Andromeda. For galaxies billions of light years away, individual stars blur together, and the best we can do is observe the overall spectra of galaxies, not individual stars. But thanks to a chance alignment, we can now observe dozens of stars in a galaxy so distant we see it at a time when the Universe was half its present age.

The results are published in Nature Astronomy, and they focus on JWST observations of a cluster of galaxies known as Abell 370. This galactic cluster is famous because it acts as a gravitational lens for more distant galaxies behind it. You can see them as arcs of light in the image above. One prominent arc, highlighted in the image, is known as The Dragon. It is made up of the lensed and magnified images of several galaxies, the light of which has traveled 5 to 7 billion years to reach us.

The Dragon has been studied before using observations from the Hubble Space Telescope, and from these studies astronomers have been able to see a handful of blue supergiant stars, which are the largest and brightest main sequence stars. But identifying individual stars is notoriously difficult. In this new study, the team used JWST observations of The Dragon from 2022 and 2023. Since the Webb is capable of capturing high-resolution images in the infrared, it’s perfectly suited to study the spectra of redshifted stars in the cosmic middle age.

Individual stars identified in the Dragon arc in 2022 and 2023. Credit: Yoshinobu Fudamoto, et al

But even the Webb would be hard-pressed to identify more than a few bright stars within The Dragon, were it not for a second effect of gravitational lensing known as microlensing. Within the distant galaxy, two stars can line up just so, and the more distant star is gravitationally magnified for a short time, like a flare. This allows astronomers to study the spectra of the distant star. So a galaxy from 7 billion years ago is lensed into a bright arc of light by the Abell 370 cluster, and within that galaxy stars are further microlensed by a stellar alignment.

The team was able to identify more than 40 microlensing events, and was therefore able to capture the spectra of more than 40 individual stars in the distant galaxy. Based on the spectra, these stars are red supergiants similar to Betelgeuse. The study shows that microlensing events such as these are common, so we should be able to see lots more stars in this distant galaxy in the future.

We know a great deal about red supergiants in the Milky Way. Since they are dying stars, red giants play a significant role in enriching the available elements in a galaxy, which determines things such as the formation of stars and even life. But by studying these distant red giants, we will be able to see how they impacted the chemical diversity of younger galaxies. It could even help us understand what the Milky Way was like when the Sun and Earth began to form.

Reference: Yoshinobu Fudamoto, et al. “Identification of more than 40 gravitationally magnified stars in a galaxy at redshift 0.725.” Nature Astronomy (2025).

The post A Dragon Reveals Individual Stars From A Time When the Universe Was Half Its Present Age appeared first on Universe Today.

Many people decide to give up alcohol during January. But is this actually helpful in the long-term and are there better, easier ways to change our drinking habits, asks Ian Hamilton