The event horizon is a fascinating part of a black hole’s anatomy. In 2017, telescopes around the world gathered data on the event horizon surrounding the supermassive black hole at the heart of M87. This was the first time we had ever seen an image of such a phenomenon. Since then, 120,000 more images of the region have been captured and, as astronomers sift through the data, their model of M87’s event horizon has evolved.
Black holes, formed from the collapse of massive stars or in some cases through other processes, are regions of space-time where gravity is so intense that it warps the fabric of the universe. The event horizon is the boundary surrounding a black hole, beyond which nothing—not even light—can escape its gravitational pull. It marks the point of no return for any matter or radiation that gets too close. Within the event horizon, the curvature of space-time becomes infinite, leading to a singularity, a point where density and gravity reach extremes that modern physics and mathematics struggle to model. The event horizon’s properties are critical to understanding black holes, as it represents the outermost layer hiding everything within.
This artist’s impression shows a black hole about 800 million years after the Big Bang, during one of its short periods of rapid growth. Image Credit: Jiarong GuOne such object sits at the centre of most galaxies and in particular at the centre of M87, a massive elliptical galaxy 53 million light years away. It’s approximately 120,000 light years across with an estimated trillion stars. At its core is a supermassive black hole which weighs in at about 6.5 billion times the mass of the Sun. It was this object which was imaged back in 2017 for the first time.
The jet emerging from the galactic core of M87. NASA/STScI/AURA.Since that first image of the event horizon around the M87 black hole, over 120,000 images have been used to analyse how the horizon has evolved since the first images were captured. Like all black holes, M87’s has a rotational axis and it is this, that the images have revealed something unexpected.
A team of astronomers have confirmed that the axis points away from the Earth and have shown that the accretion disk suffers turbulence. Compared to images from 2017, the accretion disk has brightened and it is thought the turbulence in the accretion disk is the cause. As assistant professor Hung-Yi Pu from National Taiwan Normal University explains “the black hole accretion environment is turbulent and dynamic. Since we can treat the 2017 and 2018 observations as independent measurements, we can constrain the black hole’s surroundings with a new perspective.”
The accretion disk around M87* (as the black hole is referred to) is a swirling disk of gas and dust that orbits around the black hole before being pulled in. The disk forms when matter is stripped off nearby stars or from interstellar gas before spiralling in to the black hole under its immense gravitational pull. As the material accelerates in the disk and gets compressed, it heats up to millions of degrees, emitting radiation across the electromagnetic spectrum. It’s this radiation that often reveals the presence of a black hole.
3D rendering of a rapidly spinning black hole’s accretion disk and a resulting black hole-powered jet. Credit: Ore Gottlieb et al. (2024)The discoveries from the super computer generated images reveal more about the dynamics in the regions surrounding a black hole. They find that material spiralling into a black hole from afar can either flow in the direction of the black hole’s rotation or in the opposite direction.
Source : M87 One Year Later: Catching the Black Hole’s Turbulent Accretion Flow
The post Watching the Changing M87 Black Hole Event Horizon appeared first on Universe Today.
Athayde Tonhasca Júnior contributes another text-and-photo essay to the site, this time showing how a thorough knowledge of ecology is required to save a declining species. His ID’s and captions are indented, and you can enlarge his photos by clicking on them.
The butterfly, the plant, and the ant
All news is bad news, it seems, especially about the environment. Melting glaciers, oceans choked with plastic, relentless deforestation, extinctions. In the face of such a depressing deluge, we could do with a feel-good tale. And as inspiring tales go, it’s hard to beat the Large Blue Story.
The large blue butterfly (Phengaris arion) has always been rare in Britain, but its numbers were found to be alarmingly low by 1972 and falling steadily thereafter. In 1979, it became extinct in the British Isles. At first, collectors were blamed for the large blue’s demise, which was a reasonable explanation considering the rarity and the appeal of such a beautiful butterfly. But soon attention was directed to another possibility: the depletion of wild thyme (Thymus praecox), the main food for the butterfly’s early larval instars (developmental stages). It turned out that food losses contributed to the large blue extinction, but the plot was considerably thicker.
The large blue butterfly, Phengaris arion. The species’ taxonomy is a matter of dispute, so it is also known as Maculinea arion © PJC&Co, Wikimedia Commons:
The large blue and about 75% of the 6,000 or so related species (family Lycaenidae) are myrmecophilous, that is, they are associated with ants. These butterfly-ant relationships vary in form and intensity, but in the case of the large blue, red ants (Myrmica spp.) mean food: without them, the butterfly cannot survive.
A female large blue lays her eggs on the flower buds of wild thyme – wild marjoram (Origanum vulgare) would do, but it usually flowers too late in the season for the butterfly. The emerging caterpillars eat the wild thyme flower heads and seeds for the first few weeks of their lives, like any ordinary butterfly. Siblings are also fair game: if two eggs hatch on the same flower, one baby caterpillar will eat the other. Then the surviving one goes full Dr Jekyll and Mr Hyde.
The grown caterpillar drops to the ground and starts releasing substances that attract worker ants, including pheromones that mimic the aroma of red ant larvae. When an ant bumps into it, the caterpillar stretches and twists to assume the shape of an ant larva. So instead of attacking the juicy, soft and nutritious caterpillar, the chemically mesmerised ants take their ‘stray young’ back to their nest. There the caterpillar is cared for just like the ants’ own brood.
Once inside an ant nest, some lycaenid species adopt a cuckoo lifestyle; they induce the ants to nurse and feed them through regurgitation. Not the large blue (and some related species): they feed on ant larvae, all the while secreting sugary substances to keep the ant workers happy.
A greater large blue (P. arionides) caterpillar feeding on M. kotokui larvae © Ueda et al., 2016:
The caterpillar carries on eating ant grubs until it pupates the following spring. The emerging adult crawls to the surface and seeks refuge in the nearby vegetation, where it expands its wings and flies away in search of a mate.
A gravid female butterfly (1) is attracted to wild marjoram (2) and lays her eggs on suitable flower buds (3). A fourth-instar caterpillar drops to the ground and is ‘adopted’ by ants (4). The caterpillar spends 11 months inside the ants’ nest, feeding on their brood (5) © Casacci et al., 2019:
The above was a summary of the complex biology and ecology of the large blue: UK butterflies has the full story.
The large blue’s reliance on wild thyme and red ants has been known for a long time, but none of the conservation efforts prevented its extinction in 1979. Things started to change when a PhD student – today Professor Jeremy Thomas, OBE, made a crucial discovery. Not just any red ant would do for the large blue. It needs one specific species: M. sabuleti (M. scabrinodis is an alternative host, but butterfly survival is poor with this ant).
Myrmica sabuleti, the crucial host for the large blue © B. Schoenmakers, Wikimedia Commons.
Thomas’ findings opened a whole new perspective for large blue conservation. If M. sabuleti populations are not doing well, the butterfly cannot do well either, regardless of the quantity and condition of the host plant.
It turns out that the survival and abundance of this ant depend largely on one factor: sunshine, which warms their nests. If grasses that grow alongside wild thyme are too tall, the ant nests will become shaded, cold and wet: the colonies will fail or be too small to sustain large blue populations. One caterpillar may require 200 ant larvae to reach adulthood, and about 350 ant workers may be needed to rear a single caterpillar. The conclusion from these findings was that fencing, thought to help the butterfly by keeping thyme-munchers at bay, is actually bad for the ants.
Wild thyme in full sunshine maintains healthy M. sabuleti colonies © GT1976, Wikimedia Commons:
Armed with this information, Nature Conservancy (now Natural England) and the Centre for Ecology and Hydrology launched a reintroduction programme, and its linchpin was the creation and management of adequate conditions for both the butterfly and the ant. Conservation organisations, land managers and volunteers set out to monitor large blue and M. sabuleti populations, manage grazing to keep the grass short, clear scrub and plant wild thyme. When a pilot site was considered in favourable condition in 1983, large blue specimens were brought in from Sweden. More releases followed at several suitable sites during subsequent years. Today, large blue colonies are more abundant and larger than they were in the 1950s.
The rescue of the large blue butterfly is a textbook case of species conservation, known and celebrated around the world. It inspires and shows us that science, hard work and goodwill go a long way to restore and protect our natural world.
A classic scene from several high sci-fi movies and shows is when the characters approach their new spaceship in space for the first time. It is typically attached to a massive structure – think of the Kuat Drive Yards in Star Wars or the Utopia Planitia Fleet Yards around Mars in Star Trek. These gigantic structures play a role akin to what dry docks do for modern navies – they allow for the construction of ships in a relatively controlled environment with access to tools and equipment specialized for their construction. That is the idea behind a new NASA Institute for Advanced Concepts (NIAC) grant to ThinkOrbital, a company specializing in In-space assembly, manufacturing, and construction (ISAM&C). Their idea is to build a “Construction Assembly Destination” in orbit to build spacecraft in space.
That might seem like a lofty goal, but ThinkOrbital has some pedigree in doing ISAM&C tasks that no one else has done before. In May 2024, they launched and successfully tested the first-ever weld in space. The mission flew on a Falcon 9, spot-welded together some quarter-inch pieces of aluminum, and returned it to Earth, where the welds were closely examined.
They used a method called electron beam welding, which has several advantages for use in space. First, it doesn’t require as much power as a traditional arc welder—only around 2KW, equivalent to a household iron. Second, it doesn’t create a lot of heat, which can degrade the metal being welded and cause issues like splintering, which can become dangerous in zero-gravity situations.
Video describing the ThinkOrbital welder launch and test.Doing a simple weld is a far cry from building an entire floating dry dock, but it is a step in that direction. Vojtech Holub, ThinkOrbital’s co-founder and CIO, said in an interview with Fraser that the company had actually submitted a proposal to NIAC for a more moderate step in the development of ISAM&C technology. However, the idea for a space station four times the size of the ISS “was not deemed futuristic enough.”
That rejection inspired the company to go bigger – by suggesting an entire orbital construction platform. In the interview, Dr. Volub talks about creating an interior space of 4,000 cubic meters by launching exterior plates akin to the hexagons on a soccer ball and welding them together in space using the company’s existing welder technology. In theory, if the process can be repeated, you could even build a large enough station to make something “up to [the size of] an Imperial Star Destroyer,” according to Dr. Holub.
There are some obvious difficulties in scaling up to that level, including requiring thicker plates and how to introduce gravity to any human occupants. Still, the general idea is scalable well beyond anything currently in orbit. As part of the NIAC grant, Dr. Holub and his team will have to develop a concept of operations (or CONOPS) for the development of the station, including how many launches it would take, what kind of structural loads it would be under, and how it would be assembled once it was up there.
The Orb2 was the original concept, introduced in a paper by Vojtech Holub, that spawned the idea of ThinkOrbital.With answers to those questions in hand, ThinkOrbital would potentially be given a Phase II NIAC grant that would allow them to start building some prototypes to de-risk the technology. But they’ve got to complete Phase I first and compete with plenty of other ideas that NIAC has selected. If they are picked for a Phase II grant, though, it could move the start-up from concept to the reality of building a massive space for constructing space infrastructure – something humanity will need when it expands more throughout the solar system.
Learn More:
NASA / ThinkOrbital – Construction Assembly Destination
Vojtech Holub – Orb2: Spherical Space Station Designed for Single Launch and On-Orbit Assembly
UT – Blue Origin Announces the “Orbital Reef,” the Space Station they Plan to Build in Orbit
UT – Gateway Foundation Gives a Detailed Update on its Voyager Station Concept
Lead Image:
Artist concept highlighting the novel approach proposed by the 2025 NIAC awarded selection of Construction Assembly Destination
Credit – NASA/Ryan Benson/ThinkOrbital
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On January 20th a Chinese tech company released the free version of their chatbot called DeepSeek. The AI chatbot, by all accounts, is about on par with existing widely available chatbots, like ChatGPT. It does not represent any new abilities or breakthrough in quality. And yet the release shocked the industry causing the tech-heavy stock market Nasdaq to fall 3%. Let’s review why that is, and then I will give some thoughts on what this means for AI in general.
What was apparently innovative about DeepSeek is that, the company claims, it was trained for only $8 million. Meanwhile ChatGPT 4 training cost over $100. The AI tech industry is of the belief that further advances in LLMs (large language models – a type of AI) requires greater investments, with ChatGPT-5 estimated to cost over a billion dollars. Being able to accomplish similar results at a fraction of the cost is a big deal. It may also mean that existing AI companies are overvalued (which is why their stocks tumbled).
Further, the company that made DeepSeek used mainly lower power graphics chips. Apparently they did have a horde of high end chips (the export of which are banned to China) but was able to combine them with more basic graphics chips to create DeepSeek. Again, this is what is disruptive – they are able to get similar results with lower cost components and cheaper training. Finally, this innovation represents a change for the balance of AI tech between the US and China. Up until now China has mainly been following the US, copying its technology and trailing by a couple of years. But now a Chinese company has innovated something new, not just copied US technology. This is what has China hawks freaking out. (Mr. President, we cannot allow an AI gap!)
There is potentially some good and some bad to the DeepSeek phenomenon. From a purely industry and market perspective, this could ultimately be a good thing. Competition is healthy. And it is also good to flip the script a bit and show that innovation does not always mean bigger and more expensive. Low cost AI will likely have the effect of lowering the bar for entry so that not only the tech giants are playing. I would also like to see innovation that allows for the operation of AI data centers requiring less energy. Energy efficiency is going to have to be a priority.
But what are the doomsayers saying? There are basically two layers to the concerns – fear over AI in general, and fears over China. Cheaper more efficient AIs might be good for the market, but this will also likely accelerate the development and deployment of AI applications, something which is already happening so fast that many experts fear we cannot manage security risks and avoid unintended consequences.
For example, LLMs can write code, and in some cases they can even alter their own code, even unexpectedly. Recently an AI demonstrated the ability to clone itself. This has often been considered a tipping point where we potentially lose control over AI – AI that an iterate and duplicate itself without human intervention, leading to code no one fully understands. This will make it increasingly difficult to know how an AI app is working and what it is capable of. Cheaper LLMs leading to proliferation obviously makes all this more likely to happen and therefore more concerning. It’s a bit like CRISPR – cheap genetic manipulation is great for research and medical applications, but at some point we begin to get concerned about cheap and easy genetic engineering.
What about the China angle? I wrote recently about the TikTok hubbub, and concerns about an authoritarian rival country having access to large amounts of data on US citizens as well as the ability to put their thumb on the scale of our internal political discourse (not to mention deliberate dumbing down our citizenry). If China takes the lead in AI this will give them another powerful platform to do the same. At the very least it subjects people outside of China to Chinese government censorship. DeepSeek, for example, will not discuss any details of Tiananmen Square, because that topic is taboo by the Chinese government.
It is difficult to know, while we are in the middle of all of this happening, how it will ultimately play out. In 20 years or so will we look back at this time as a period of naive AI panic, with fears of AI largely coming to nothing? Or will we look back and realize we were all watching a train wreck in slow motion while doing nothing about it? There is a third possibility – the YdK pathway. Perhaps we pass some reasonable regulations that allow for the industry to develop and innovate, while protecting the public from the worst risks and preventing authoritarian governments from getting their hands on a tool of ultimate oppression (at least outside their own countries). Then we can endlessly debate what would have happened if we did not take steps to prevent disaster.
The post The Skinny on DeepSeek first appeared on NeuroLogica Blog.
Exoplanets have captured the imagination of public and scientists alike and, as the search continues for more, researchers have turned their attention to the evolution of metallicity in the Milky Way. With this answer comes more of an idea about where planets are likely to form in our Galaxy. They have found that stars with high-mass planets have higher metallicity than those with lower amounts of metals. They also found that stars with planets tend to be younger than stars without planets. This suggests planetary formation follows the evolution of a galaxy with a ring of planet formation moving outward over time.
The search for exoplanets has largely been one of surveying nearby stars. That generally means we are exploring stars in our region of the Galaxy. As technology develops, our ability to detect them improves and to date, nearly 6,000 planets have been discovered around other stars. A number of different techniques have been used to find them such as the transit method – which detects the dimming of a star’s light due to the presence of the passage of a planet, or the radial velocity method which measures the wobble of a star due to the gravitational tug of a planet.
This artist’s impression depicts the exomoon candidate Kepler-1625b-i, the planet it is orbiting and the star in the centre of the star system. Kepler-1625b-i is the first exomoon candidate and, if confirmed, the first moon to be found outside the Solar System. Like many exoplanets, Kepler-1625b-i was discovered using the transit method. Exomoons are difficult to find because they are smaller than their companion planets, so their transit signal is weak, and their position in the system changes with each transit because of their orbit. This requires extensive modelling and data analysis.One key aspect of planetary development in the Galaxy is the presence of metals (elements heavier than hydrogen and helium.) known as metallicity. These elements are formed during the life cycle of a star, especially during supernova explosions. They are scattered through space and form part of the interstellar medium. Understanding the abundance and distribution of metals provides an insight into the age, history and formation rates of stars and planets.
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/DPACA team of researchers led by Joana Teixeira from the University of Porto in Portugal have been exploring something known as the Galactic Birth Radii (rBirth) This term relates to the distance from galactic centre that stars and therefore planets are forming. Using photometric, spectroscopic and astrometric data, the team were able to estimate the ages of two groups of stars, those with planets and those without. This enabled them to rBirth for exoplanets based upon the original star positions (having calculated them from their age and levels of metals present within.)
The results of the analysis showed that stars hosting planets had a higher [Fe/H], are younger and were born closer to the centre of the galaxy than those without (Fe/H refers to the amount of iron relative to the amount of hydrogen in a star or galaxy, where the Sun is [Fe/H]=0.3.) The team went further to state that from one data set (from the Stellar Parameters of Stars with Exoplanets Catalog,) the results suggest that stars hosting high mass planets have a different iron to hydrogen radio and age distribution than stars with at least one low mass planet and those with only low mass planets.
The ESA/NASA Solar Orbiter has given us our highest resolution images of the Sun ever. They show us sunspots, plasma, and magnetic fields, and more. Image Credit: ESAThe research reveals that high mass planets or in other words terrestrial planets tend to form around stars with higher [Fe/H] and younger stars compared to low mass. Similarly, those with a mixture of high and low mass planets also formed around higher [Fe/H], young stars.
It’s an interesting study worthy of further investigations. Understanding that Earth-like planets tend to form around star systems that formed around the inner regions of the Galaxy. Here the supply of metals is more abundant and, even though the stellar systems can migrate to outer regions of the Milky Way it gives a better focus on the hunt for planetary systems beyond our own.
Source : Where in the Milky Way Do Exoplanets Preferentially Form?
The post Planet Formation Favors the Metal-Rich Inner Milky Way appeared first on Universe Today.
Just as important as the question of how much the livestock industry contributes to global warming is whether your giving up meat will have any real impact.
Learn about your ad choices: dovetail.prx.org/ad-choicesAstronomers have found two planets around two separate stars that are succumbing to their stars’ intense heat. Both are disintegrating before our telescopic eyes, leaving trails of debris similar to a comet’s. Both are ultra-short-period planets (USPs) that orbit their stars rapidly.
These planets are a rare sub-class of USPs that are not massive enough to hold onto their material. Astronomers know of only three other disintegrating planets.
USPs are known for their extremely rapid orbits, some completing an orbit in only a few hours. Since they’re extremely close to their stars, they’re subjected to intense heat, stellar radiation, and gravity. Many USPs are tidally locked to their star, turning the star-facing side into an inferno. USPs seldom exceed two Earth radii, and astronomers think that about 1 in 200 Sun-like stars has one. They were only discovered recently and are pushing the boundaries of our understanding of planetary systems.
There are plenty of unanswered questions about USPs. Their formation mechanism is unclear, though they likely migrated to their positions rather than formed there. They’re difficult to observe because of their proximity to their stars, making questions about their structures difficult to answer.
Fortunately, two separate teams of researchers have spotted the two disintegrating USPs. As they spill their contents out into space in tails, they’re giving astronomers an opportunity to see what’s inside them.
The new observations are in two new papers available at the pre-press site arxiv.org. One is “A Disintegrating Rocky Planet with Prominent Comet-like Tails Around a Bright Star.” The lead author is Marc Hon, a postdoctoral researcher at the MIT TESS Science Office. This paper is referred to hereafter as the MIT study.
“We report the discovery of BD+054868Ab, a transiting exoplanet orbiting a bright K-dwarf with a period of 1.27 days,” the authors write. The TESS spacecraft found the planet, and its observations “reveal variable transit depths and asymmetric transit profiles,” the paper states. Those are characteristics of dust coming from the doomed planet and forming tails: one on the leading edge and one on the trailing edge. Dust particle size in each tail is different, with the leading trail containing larger dust and the trailing tail containing finer grains.
This figure from the team’s modelling illustrates some of their findings. “A view from above the planetary orbit, looking down at the x ? y plane in which the planet is orbiting counterclockwise. The trails indicate the accumulated trajectories of the dust grains over time. There are two distinct trails that correspond to the leading and trailing dust tails,” the authors explain. The planet is not to scale in this image, but the host star is. Image Credit: Hon et al. 2025.“The rate at which the planet is evaporating is utterly cataclysmic, and we are incredibly lucky to be witnessing the final hours of this dying planet’,'”
Marc Hon, MIT TESS Science Office“The disintegrating planet orbiting BD+05 4868 A has the most prominent dust tails to date, “said lead author Hon. “The dust tails emanating from the rapidly evaporating planet are gigantic. Its length of approximately 9 million km encircles over half the planet’s orbit around the star every 30 and a half hours,” he added.
The MIT study shows that the planet is losing mass at the rate of 10 Earth masses of material per billion years. Since the object is probably only roughly the size of Earth’s Moon, it will be totally destroyed in only a few million years. “The rate at which the planet is evaporating is utterly cataclysmic, and we are incredibly lucky to be witnessing the final hours of this dying planet,” said Hon.
The host star is probably a little older than the Sun and has a companion red dwarf separated by about 130 AU. The authors think that the planet is a great candidate for follow-up studies with the JWST. Not only is the star bright, but the transits are deep. Because of the leading and trailing tails, the transits can last up to 15 hours.
The Las Cumbres Observatory captured this image of the two stars. The main sequence star is on the right, and its red dwarf companion is on the left. Image Credit: LCO/Hon et al. 2025.“The brightness of the host star, combined with the planet’s relatively deep transits (0.8?2.0%), presents BD+054868Ab as a prime target for compositional studies of rocky exoplanets and investigations into the nature of catastrophically evaporating planets,” they explain.
“What’s also highly exciting about BD+05 4868 Ab is that it has the brightest host star out of the other disintegrating planets —about 100 times brighter than K2-22—establishing it as a benchmark for future disintegrating studies of such systems,” said Avi Shporer, a Research Scientist at the MIT Kavli Institute for Astrophysics and Space Research and a co-author of the MIT paper. “Prior to our study, the three other known disintegrating planets were around faint stars, making them challenging to study,” he added.
The second paper is “A Disintegrating Rocky World Shrouded in Dust and Gas: Mid-IR Observations of K2-22b using JWST.” The lead author is Nick Tusay, a PhD student at Penn State working in the Center for Exoplanets and Habitable Worlds. This paper is hereafter referred to as the Penn State study.
“The effluents that sublimate off the surface and condense out in space are probably representative of the formerly interior layers convectively transported to the molten surface,” the authors write. In this work, astronomers were able to observe its debris with the JWST’s MIRI and also with other telescopes. The observations show that the material coming from the USP is not likely to be iron-dominated core material. Instead, they’re “consistent with some form of magnesium silicate minerals, likely from mantle material,” the authors explain.
“These planets are literally spilling their guts into space for us, and with JWST we finally have the means to study their composition and see what planets orbiting other stars are really made of,” said lead author Tusay.
We can’t see what’s inside the planets in our Solar System, though seismic waves and other observations give scientists a pretty good idea about Earth’s interior. By examining the entrails coming from K2-22b, astronomers are learning not only about the planet but, by extension, about other rocky planets. The irony is that they’re so far away.
“K2-22b has an asymmetric transit profile, as the planet’s dusty cloud of effluents comes into view in front of the star, showing evidence of extended tails like a comet.”
“It’s a remarkable and fortuitous opportunity to
understand terrestrial planet interiors.”
“It’s remarkable that directly measuring the interior of planets in the Solar System is so challenging—we have only limited sampling of the Earth’s mantle, and no access to that of Mercury, Venus, or Mars—but here we have found planets hundreds of light years away that are sending their interiors into space and backlighting them for us to study with our spectrographs,” said Jason Wright, Professor of Astronomy and Astrophysics, co-author of the Penn State study, and Tusay’s PhD supervisor. “It’s a remarkable and fortuitous opportunity to understand terrestrial planet interiors,” he added.
While TESS discovered the disintegrating planet in the previous paper, Kepler found this one during its extended K2 mission. This one orbits its M-dwarf star in only 9.1 hours. Evidence of its tail is in the variability of its light curve. “The dramatic variability in lightcurve transit depth (0–1.3%) combined with the asymmetric transit shape suggests we are observing a transient cloud of dust sublimating off the surface of an otherwise unseen planet,” the MIT paper states.
As this figure from the research shows, each of K2-22b’s transits lasts about 46 minutes. Each blue point represents 8 minutes. Image Credit: Tusay et al. 2025.According to the authors, this could be the first time we’ve seen outgassing from a vaporizing planet. “The shorter MIRI wavelength features … may constitute the first direct observations of gas features from an evaporating planet,” the paper states.
“Unexpectedly, the models that best fit these measurements seem to be ice-derived species (NO and CO2),” the authors write. Though the spectrum is broadly consistent with a rocky body, the presence of NO and CO2 is a bit of a curveball. These materials are more similar to icy bodies like comets rather than rocky planets.
“It was actually sort of a ‘who-ordered-that?’ moment,” Tusay said about finding the icy features. For this reason, the researchers are eager to point the JWST at the planet again to obtain more and better data. Multiple pathways can generate these results, and only better data can help astronomers determine what’s going on.
According to the authors, the wavelength features in the spectrum “may constitute the first direct observations of gas features from an evaporating planet.” Rather unexpectedly, the results indicate ice-derived chemical species. Image Credit: Tusay et al. 2025.Though we’re in the early days of observing planets like this one, scientists still have some expectations. These results defy those expectations since many expected to find only the iron-core remnants of these USPs.
“We didn’t know what to expect,” said Wright, who also co-authored an earlier study on how to use JWST to probe these exoplanetary tails. “We were hopeful they might still have their mantles, or potentially even crust material that was being evaporated. JWST’s mid-infrared spectrograph MIRI was the perfect tool to check, because crustal, silicate mantle, and iron core materials would all transmit light in different ways that JWST could distinguish spectroscopically,” Wright added.
Next, both teams of scientists hope to point the JWST at BD+05 4868 Ab from the MIT study. Its star is far brighter than the other stars known to host disintegrating USPs. A bright light source makes it much easier for the JWST to get stronger results.
“What’s also highly exciting about BD+05 4868 Ab is that it has the brightest host star out of the other disintegrating planets —about 100 times brighter than K2-22—establishing it as a benchmark for future disintegrating studies of such systems,” said Avi Shporer, a Research Scientist at the MIT Kavli Institute for Astrophysics and Space Research and a co-author of the MIT project. “Prior to our study, the three other known disintegrating planets were around faint stars, making them challenging to study,” he added.
When the JWST was launched, it wasn’t aimed at observing disintegrating exoplanets. But this research shows off a new way of using the powerful telescope. Surprises like this are a part of every new telescope or observing effort, and researchers often look forward to them.
“The data quality we should get from BD+05 4868 A will be exquisite,” said Shporer. “These studies have proven the validity of this approach to understanding exoplanetary interiors and opened the door to a whole new line of research with JWST.”
The post Exoplanets Seen Falling Apart appeared first on Universe Today.
Exoplanet exploration has taken off in recent years, with over 5500 being discovered so far. Some have even been in the habitable zones of their stars. Imaging one such potentially habitable exoplanet is the dream of many exoplanet hunters, however, technology has limited their ability to do that. In particular, one specific piece of technology needs to be improved before we can directly image an exoplanet in the habitable zone of another star – a starshade. Christine Gregg, a researcher at NASA Ames Research Center, hopes to contribute to the effort of developing one and has received a NASA Institute for Advanced Concepts (NIAC) grant as part of the 2025 cohort to work on a star shade that is based on a special type of metamaterial.
To understand the goal of Dr. Gregg and her team, it’s best first to understand what starshades do and what’s holding them back from being deployed. A starshade is designed to float in tandem with a space telescope and block out the light from a specific star, allowing the telescope to capture light directly from the much-less bright planet that is orbiting the star. That light can contain information about its size, orbital period, and even its atmospheric composition that would otherwise be lost in the overwhelming brightness of the planet’s star.
The shape of a starshade, which traditionally looks like a flower petal, might seem counterintuitive at first – if you’re trying to block a star’s light, why not just make the shape circular? But starlight coming from far away can diffract around a simple circle structure. The petals are explicitly designed to stop that from happening and completely block out even diffracted light around the shape’s edges.
Fraser interviews another Starshade expert – Dr. Markus Janson from Stockholm UniversityBut it’s not the shape that makes it hard to deploy—it’s its size. Starshades are typically designed to be hundreds of meters across. Therefore, they are impossible to fit inside a traditional rocket fairing fully assembled. What’s more, they have to move along with the telescope—if the telescope the starshade is meant to accompany is pointed at another star and redirected, the starshade has to move with it.
The wrinkle is that the starshade is likely tens of thousands of kilometers from the telescope it is designed to assist. So, a slight change of a few degrees of inclination for the telescope would mean hundreds of thousands of kilometers of travel for its associated starshade. That kind of movement requires a lot of fuel, which is also costly due to the weight requirements of launching these objects so far away.
No wonder a starshade has yet to be successfully deployed in space. Combining gigantic sizes that don’t fit inside rocket fairings and massive amounts of fuel to relocate every time the telescope needs to look at a different star are significant strikes against the concept. However, if humanity wants to directly image an exoplanet in the habitable zone of another star, there is still no better way to do so.
NASA animation of the deployment of a starshadeEnter Dr Gregg’s idea—she proposes using metamaterials for her starshade, which is robotically constructed in orbit. Metamaterials have several advantages over existing proposed starshades (one of which, by Nobel Prize winner John Mather, is another NIAC recipient this year).
First, metamaterials are lighter. As with all things launched into space, being lighter means less cost – or, in this case, the ability to bring more fuel, allowing the starshade to operate longer than alternatives.
Second, the specific kinds of metamaterials she proposes to use are much less likely to break. As she mentioned to Fraser in an interview, “The more stiffness a material has, the less damping it has. It’s just sort of a natural trade-off”. So, if a starshade is made from traditional materials, it would either be stiff and rigid but prone to vibrational strain when moving between positions or being deployed, or it would be very flexible but would have difficulty holding its shape when it’s supposed to.
This video shows phononic materials in action.The metamaterial Dr. Gregg and her colleagues have proposed uses a type of material that both holds its structure well but also suppresses vibration by a unique use of a material called a phononic crystal. These were initially engineered to dissipate sound waves. This means that when used as a material in a starshade, it could dampen any feedback on the structure from things like micrometeoroid impacts, solar radiation, or even the process of deployment and assembly.
Using robots to deploy the starshade is another focal point of Dr. Gregg’s work, as she discusses with Fraser. Still, for this Phase I NIAC project, she is focusing on developing the model for starshade itself and selecting the appropriate material. As with all NIAC projects, she can apply for more funding in a Phase II round upon completion of her Phase I. If she receives it, humanity will be one step closer to seeing a giant floating petal in space – but one with very particular mechanical and structural properties.
Learn More:
NASA / C. Gregg – Dynamically Stable Large Space Structures via Architected Metamaterials
UT – In Order to Reveal Planets Around Another star, a Starshade Needs to Fly 40,000 km Away from a Telescope, Aligned Within Only 1 Meter
UT – Starshade Prepares To Image New Earths
UT – To Take the Best Direct Images of Exoplanets With Space Telescopes, we’re Going to Want Starshades
Lead Image:
Artist concept highlighting the novel approach proposed by the 2025 NIAC awarded selection of the Dynamically Stable Large Space Structures via Architected Metamaterials concept. NASA/Christine Gregg
The post Dynamically Stable Large Space Structures via Architected Metamaterials appeared first on Universe Today.
Star formation in the early Universe was a vigorous process that created gigantic stars. Called Population 3 stars, these giants were massive, extremely luminous stars, that lived short lives, many of which were ended when they exploded as primordial supernovae.
But even these early stars faced growth limitations.
Stellar feedback plays a role in modern star formation. As young stars grow, they emit powerful radiation that can disperse nearby gas they need to keep growing. This is called protostellar radiative feedback, and it takes place in addition to the restrictive effect their magnetic fields have on their growth.
However, new research shows that the growth of Pop 3 stars was limited by their magnetic fields.
The research is titled “Magnetic fields limit the mass of Population III stars even before the onset of protostellar radiation feedback.” The lead author is Piyush Sharda, an astrophysicist at the Leiden Observatory in the Netherlands. It’s available on the pre-print server arxiv.org.
Scientists observe stars forming in the modern Universe to understand how the process plays out. This is difficult because stars take so much time to form, while we’ve only been watching young stars from a great distance for a few decades. Stars are massive, energetic, complex objects that don’t give up their secrets easily.
There are many unanswered questions about star formation, but a general picture has emerged. It starts with a cloud of cold molecular hydrogen that collapses into dense cores. These cories become protostars, also called young stellar objects (YSOs). Accretion disks form around the young stars, and this is where radiative feedback comes in.
This artist’s concept shows a young stellar object and the whirling accretion disk surrounding it. NASA/JPL-CaltechAs young stars accrete mass, they heat up. They radiate this heat outward into their own accretion disks. As the material in the disk heats, it slows or even stops the accretion process. So radiative feedback limits their growth.
YSOs also rotate more rapidly than more mature stars. The rotation creates powerful magnetic fields, and these fields drive jets from the YSO’s poles. These jets steal away some of the accretion energy, limiting the stars’ growth. The jets can also disperse some of the surrounding gas, further limiting their growth.
However, the picture may look different for Pop 3 stars. To begin with, their existence is hypothetical at this point in time, though theory supports it. If they’re real, astrophysicists want to know how they formed and what their growth limits were. If they’re real, Pop 3 stars played a critical role in the Universe by forging the first metals and spreading them out into space.
According to the authors of the new research, simulations haven’t been thorough enough to explain the masses of Population 3 stars.
“The masses of Population III stars are largely unconstrained since no simulations exist that take all relevant primordial star formation physics into account,” the authors write. “We evolve the simulations until 5000 years post the formation of the first star.”
In the team’s more thorough simulations, which include magnetic fields and other factors, these early stars are limited to about 65 solar masses. “In 5000 yrs, the mass of the most massive star is 65 solar masses in the RMHD <radiation magnetohydrodynamics> simulation, compared to 120 solar masses in simulations without magnetic fields,” they write.
This figure from the research shows a panel from each type of simulation: HD (hydrodynamic), MHD (magneto-hydrodynamic), RHD (radiation-hydrodynamics including ionizing and dissociating radiation feedback), RMHD (radiation-magnetohydrodynamics). They show each simulation at 5,000 years after the first star forms. White dots show the positions of Population 3 stars. Image Credit: Sharda et al. 2025The results show that both simulation runs that included magnetic fields are fragmented, leading to the formation of Pop 3 star clusters. That means that the evolution of the most massive Pop 3 stars in both runs is influenced by the presence of companion stars.
The difference comes down to gravity and magnetic fields working against each other. As young stars accrete mass, their gravitational power increases. This should draw more material into the star. But magnetic fields counteract the gravity. This all happens before radiative feedback is active.
The results also show that in both simulations that include magnetic fields, the amount of mass that reaches the envelope initially increases, then declines. However, the results were different in the simulations without magnetic fields. In those simulations, mass transfer from the envelope to the accretion disk is fast at first, creating a decline in the mass in the envelope and a build-up of mass in the disk. “This mass is consequently accreted by the star at a high rate,” the authors write.
This figure from the research illustrates some of the simulation results. It shows the mass enclosed within a disk of radius 500 au and height 50 au (from the midplane) around the most massive star. “The mass reservoir that can be accreted onto the central star in the MHD and RMHD runs eventually decreases as magnetic fields suppress gravitational collapse,” the authors explain.“We learn that magnetic fields limit the amount of gas infalling onto the envelope at later stages by acting against gravity, leading to mass depletion within the accretion disk,” the authors explain. “The maximum stellar mass of Population III stars is thus already limited by magnetic fields, even before accretion rates drop to allow significant protostellar radiative feedback.”
Though Population 3 stars are only hypothetical, our theories of physical cosmology rely on their existence. If they didn’t exist, then there’s something fundamental about the Universe that is beyond our grasp. However, our cosmological theories do a good job of explaining what we see around us in the Universe today. If we’re putting money on it, place your bets on Pop 3 stars being real.
“Radiation feedback has long been proposed as the primary mechanism that halts the growth of Pop III stars and sets the upper mass cutoff of the Pop III IMF (initial mass function),” the authors write in their conclusion. They show that magnetic fields can limit stellar growth before feedback mechanisms come into play.
“This work lays the first step in building a full physics-informed mass function of Population III stars,” the authors conclude.
The post Why The First Stars Couldn’t Grow Forever appeared first on Universe Today.