Philippa Kaur

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    in Space & Astronomy

    A fast radio burst’s unlikely source may be a cluster of old stars

    In a galaxy not so far away, astronomers have located a surprising source of a mysterious, rapid radio signal.

    The signal, a repeating fast radio burst, or FRB, was observed over several months in 2021, allowing astronomers to pinpoint its location to a globular cluster — a tight, spherical cluster of stars — in M81, a massive spiral galaxy 12 million light-years away. The findings, published February 23 in Nature, are challenging astronomers’ assumptions of what objects create FRBs.

    “This is a very revolutionary discovery,” says Bing Zhang, an astronomer at the University of Nevada, Las Vegas who was not involved in the study. “It is exciting to see an FRB from a globular cluster. That is not the favorited place people imagined.”

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    Astronomers have been puzzling over these mysterious cosmic radio signals, which typically last less than a millisecond, since their discovery in 2007 (SN: 7/25/14). But in 2020, an FRB was seen in our own galaxy, helping scientists determine one source must be magnetars — young, highly magnetized neutron stars with magnetic fields a trillion times as strong as Earth’s (SN: 6/4/20).

    The new findings come as a surprise because globular clusters harbor only old stars — some of the oldest in the universe. Magnetars, on the other hand, are young leftover dense cores typically created from the death of short-lived massive stars. The magnetized cores are thought to lose the energy needed to produce FRBs after about 10,000 years. Globular clusters, whose stars average many billions of years old, are much too elderly to have had a sufficiently recent young stellar death to create this type of magnetar. 

    To pinpoint the FRB, astronomer Franz Kirsten and colleagues used a web of 11 radio telescopes spread across Europe and Asia to catch five bursts from the same source. Combining the radio observations, the astronomers were able to zero in on the signal’s origins, finding it was almost certainly from within a globular cluster.

    “This is a very exciting discovery because it was completely unexpected,” says Kirsten, of ASTRON, the Netherlands Institute for Radio Astronomy, who is based at the Onsala Space Observatory in Sweden.

    The new FRB might still be caused by a magnetar, the team proposes, but one that formed in a different way, such as from old stars common in globular clusters. For example, this magnetar could have been created from a remnant stellar core known as a white dwarf that had gathered too much material from a companion star, causing it to collapse.

    “This is a [magnetar] formation channel that has been predicted, but it’s hard to see,” Kirsten says. “Nobody has actually seen such an event.”

    Alternatively, the magnetar could have been formed from the merger of two stars — such as a pair of white dwarfs, a pair of neutron stars or one of each — in close orbit around one another, but this scenario is less likely, Kirsten says. It’s also possible the FRB source isn’t a magnetar at all but a very energetic millisecond pulsar, which is also a type of neutron star that could be found in a globular cluster, but one that has a weaker magnetic field.

    To date, only a few FRB sources have been precisely pinpointed, and their locations are all in or close to star-forming regions in galaxies. Besides adding a new source for FRBs, the findings suggest that magnetars created from something other than the death of young stars might be more common than expected. More

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    in Space & Astronomy

    A rare collision of dead stars can bring a new one to life

    Like a phoenix, some stars may burst to life covered in “ash,” rising from the remains of stars that had previously passed on.

    Two newfound fireballs that burn hundreds of times as bright as the sun and are covered in carbon and oxygen, ashy byproducts of helium fusion, belong to a new class of stars, researchers report in the March Monthly Notices of the Royal Astronomical Society: Letters. Though these blazing orbs are not the first stellar bodies found covered in carbon and oxygen, an analysis of the light emitted by the stars suggests they are the first discovered to also have helium-burning cores.

    “That [combination] has never been seen before,” says study coauthor Nicole Reindl, an astrophysicist from the University of Potsdam in Germany. “That tells you the star must have evolved differently.”

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    The stars may have formed from the merging of two white dwarfs, the remnant hearts of stars that exhausted their fuel, another team proposes in a companion study. The story goes that one of the two was rich in helium, while the other contained lots of carbon and oxygen.These two white dwarfs had already been orbiting one another, but gradually drew together over time. Eventually the helium-rich white dwarf gobbled its partner, spewing carbon and oxygen all over its surface, just as a messy child might get food all over their face.

    Such a merger would have produced a stellar body covered in carbon and oxygen with enough mass to reignite nuclear fusion in its core, causing it to burn hot and glow brilliantly, say Tiara Battich, an astrophysicist from the Max Planck Institute for Astrophysics in Garching, Germany, and her colleagues.

    To test this hypothesis, Battich and her colleagues simulated the evolution, death and eventual merging of two stars. The team found that aggregating a carbon-and-oxygen-rich white dwarf onto a more massive helium one could explain the surface compositions of the two stars observed by Reindl and her colleagues.

    “But this should happen very rarely,” Battich says.

    In most cases the opposite should occur — the carbon-oxygen white dwarf should cover itself with the helium one. That’s because carbon-oxygen white dwarfs are usually the more massive ones. For the rarer scenario to occur, two stars slightly more massive than the sun must have formed at just the right distance apart from each other. What’s more, they needed to have then exchanged material at just the right time before both running out of nuclear fuel in order to leave behind a helium white dwarf of greater mass than a carbon-and-oxygen counterpart.

    The origins story Battich and her colleagues propose demands a very specific and unusual set of circumstances, says Simon Blouin, an astrophysicist from the University of Victoria in Canada, who was not involved with either study. “But in the end, it makes sense.” Stellar mergers are dynamic and complicated events that can unfold in many ways, he says (SN: 12/1/20). “This is just another.” More

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    in Humans

    We have lost 90 per cent of the original copies of Medieval literature

    A statistical tool borrowed from ecology suggests that there were originally 40,600 copies of stories about King Arthur and other western European heroes – but only 3648 survive

    Humans

    17 February 2022

    By Chris Stokel-Walker
    A scene from the Romance of Lancelot of the LakeThe Print Collector/Alamy
    Nine in 10 medieval manuscripts telling tales of chivalry and heroism have been lost to time, according to a new estimate that uses ecological statistical models to understand the volume of literature produced.
    Katarzyna Anna Kapitan and Daniel Sawyer at the University of Oxford and their colleagues from around Europe borrowed the ecological concept of the “unseen species model” to understand the volume of medieval literature in the genre of narrative fiction that once existed. These medieval texts include the famous stories of King Arthur and of Lancelot.
    An unseen species model is a statistical tool that ecologists can use to estimate biological diversity after surveying an area. Chances are that the survey won’t uncover all of the species in the area, but the model can use the number of observed species and their abundances to estimate how many additional species are present.Advertisement
    Join us for a mind-blowing festival of ideas and experiences. New Scientist Live is going hybrid, with a live in-person event in Manchester, UK, that you can also enjoy from the comfort of your own home, from 12 to 14 March 2022. Find out more.
    “These models use the pattern of the observed evidence to estimate what we’re not seeing,” says Sawyer.
    In the manuscript study, the researchers looked at the number of surviving copies of each manuscript – which is a little bit like the abundance of a biological species. Their model states that once all copies are missing, the manuscript is lost – a little like a species vanishing from the study area.
    They gathered records of 3648 copies of 799 works written in Dutch, French, Icelandic, Irish, English and German. The model then suggested that these copies are part of a population that originally contained 40,614 copies of 1170 works.
    “It’s very valuable for our research that we’re stepping beyond the case studies that dominate our field,” says Kapitan – in other words, it is important to engage with the manuscripts that have been lost as well as those that survive.

    Using the statistical data produced, the researchers were able to estimate that 62 per cent of copies of English romance and adventure tales have disappeared, compared with 19 per cent of copies of similar manuscripts in Irish, and 23 per cent in Icelandic.
    Finding a way to quantify the missing literature is a “holy grail”, says Kathleen Kennedy at the University of Bristol, UK, because it fills the knowledge gaps medieval scholars have about the context of existing work. “Applying statistical models from ecology offers a tantalising workaround, and the team’s findings generally support existing scholarly assessments,” she adds.
    However, Kennedy points out it is still just an estimate – even if it is one rooted in statistical rigour. “In the end, we cannot ever prove or disprove either traditional or statistical estimates of lost literary works, or the manuscripts containing them,” she says.
    Journal reference: Science, DOI: 10.1126/science.abl7655

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    in Humans

    How to create a delicious deep-fried ice cream dessert

    By Sam Wong
    StockFood
    WHEN cooking food, we need heat to diffuse from the outside to its centre. If we want food to be evenly cooked throughout, this can be a problem: by the time heat reaches the centre, the outside may be overcooked. But in some cases, we can use the slow diffusion of heat to our advantage, to create foods with a surprise in the middle.
    One example is a molten chocolate cake, aka a chocolate fondant. Essentially, this is an undercooked cake. The key is to bake it just long enough so that the outside is firm while the centre … More

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    in Humans

    Don’t Miss: A fresh look at the enduring mysteries of the big bang

    Dan Bradica
    Visit
    A New Nature at White Cube Bermondsey in London spotlights the work of the late Isamu Noguchi, whose sculptures in galvanised steel and other industrial materials explore the fundamental structures of nature.
    Chris Reardon/EPIX EntertainmentAdvertisement
    Watch
    From is a new sci-fi horror show made by the executive producers of Lost. It sees unfortunate travellers trapped in a small town in Middle America, terrorised by strange creatures that only come out at night. The series streams on Epix from 20 February.

    Read
    A Little Book About the Big Bang by Tony Rothman, a former editor at Scientific American, explores arguably the most evidenced – and at the same time most mysterious – idea in modern cosmology.

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    in Humans

    Snooze it to lose it: Does sleeping more make you eat less?

    Feedback is our weekly column of bizarre stories, implausible advertising claims, confusing instructions and more

    Humans

    16 February 2022

    Josie Ford
    Sleep, perchance to diet
    That April is the cruellest month has yet to pass peer review, but there is little doubt February is the shortest. Feedback considers this just as well. Some of our more southerly readers may be sunning themselves on the beach, but in our pre-Arctic stationery cupboard hole, we are just waiting for the winter murk to clear.
    It is at this time of year, when we are thinking about getting fit for the bikini season and doing nothing about it, that we want to read, and not question too deeply, headlines such as our own “Getting enough sleep may lower the amount of calories you eat”. The study in question, from a team at the University of Chicago Sleep Research Center, found that an extra hour’s sleep at night allowed participants to cut their energy intake by 270 calories a day – “the equivalent of around three chocolate digestive biscuits”, as the Press Association helpfully put it in its story on the research.
    Why stop there? A comforting graph swims into our head of a rising line of hours not consuming calories, crossing over a falling line of calories consumed. The most effective weight-loss mechanism is surely to never get out of bed at all.Advertisement
    Getting up the nose
    As we take some horizontal exercise, a PR puff is popped our way by a svelte, overslept-looking colleague with a straw hanging from their nose. “To inspire those who struggle to reach their recommended daily intake of water, air up is a world first in food technology that utilises retronasal smell to provide a zero-calorie, zero sugar, zero additive way to drink 100% pure water which tastes flavoured,” we read.
    Flavours “from Lime and Orange-Passionfruit to Cola and Iced Coffee” are created by using a special widget to inject bubbles of scented air into the previously 100 per cent blameless water. “We’ve revolutionised the way we drink water. You still have to use your mouth, but the taste has changed!” the company’s website continues. A welcome release for those of us who had been attempting to discover flavour by snorting our water.
    Smell my cheese
    We note merely in passing a press conference held on 7 February by New York City’s new mayor, Eric Adams, in which he claimed that people wouldn’t be able to tell the difference between “someone hooked on heroin” and “someone hooked on cheese”.
    Entirely our experience too. Meanwhile, Adams’s own claim that he eats a vegan diet has been called into question after he was seen eating fish. Given that phylogenetically there is no such thing as a fish, we can’t rule out a plant-based variety. As to the cheese thing, as Twitter user Tyler Conway remarked, “let he who has not snorted grated parmesan off the countertop cast the first stone”.
    Sperm waving
    If not cheese, SpermTree – “a species-level database of sperm morphology spanning the animal tree of life”, recently described in the journal Scientific Data-promises some real, hard science.
    What researchers get up to with descriptions of more than 4700 types of sperm, we hardly need to know. We are busy following an atavistic impulse by downloading the spreadsheet and reordering in descending order of sperm length.
    Top of the list by some margin is the fruit fly Drosophila bifurca, with sperm over 5.8 centimetres in length when fully unfurled. This strikes us as a mite exhausting for an insect just a few millimetres long. We aren’t surprised to learn elsewhere that this limits its output to a few hundred cells in its lifetime, an apparent limitation on its reproductive chances that has been dubbed the “big sperm paradox”. This is clearly a sticky problem. Still, we are pleased to learn via a graph in the SpermTree paper that publications on sperm morphology are on the up and up.
    Toast’s flip side
    “Dear Professor Feedback,” Jonty Rix writes, warming the cockles of our heart. “As a social scientist,” he continues, chilling our blood again, “I am perplexed (and a little disappointed) by the failure of your discussions about the landing outcomes of ‘toast’ to fully consider socio-cultural or post-materialist understandings of the possibilities.”
    We are beginning to regret reopening correspondence on the fate of falling buttered toast (8 January). But pray continue. “For example, the nature of upness seems a fundamental problem, as does a lack of a rich consideration of the numerous spaces in which toast is experienced, and of course our underlying definitions of toast and butter and the power relations inherent in their production and usage.”
    We nod uneasily, wary of saying the wrong thing. We hope some opening into this whole new metalevel of debate is given by Toby Bateson. He disagrees with our assertion, backed up with references, that toast will always land butter-side down in any universe that supports intelligent bipeds (29 January). “By simply making the toast twice as long it will rotate at half the speed and so will land butter side up,” he writes. “The problem arises due to a fundamental flaw in the proportions of toast which can be adapted to solve the problem in any universe, regardless of table height and the intelligence of the bipeds who made the toast.”
    We’re off to have a lie-down and burn some calories.
    Got a story for Feedback?
    Send it to feedback@newscientist.com or New Scientist, Northcliffe House, 2 Derry Street, London W8 5TTConsideration of items sent in the post will be delayed More

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    in Humans

    Petrov’s flu review: A surreal journey through one man’s delirium

    Petrov’s Flu is an ode to Russian sci-fi and absurdist artSergey Ponomarev/Sovereign Films
    Petrov’s Flu
    Kirill Serebrennikov
    In UK cinemas nowAdvertisement
    PETROV (Semyon Serzin) is riding a trolleybus home across the snowbound city of Yekaterinburg when a fellow passenger mutters that the rich deserve to be shot. Seconds later, the bus stops, Petrov is pulled onto the street and a rifle is pressed into his hands. Street executions follow. Then, he is back on the bus and it is unclear how much of that actually happened.
    Petrov’s Flu is an ambitious, mischievous film, one that is rich in allusions to Russian history, literature and cinema. It is also a painfully precise, gut-wrenching depiction of what it is like to run a high fever. Seeing everything from Petrov’s sick, disjointed point of view, we find the real world sliding away again and again, often into violent absurdity.
    Petrov’s fever gradually breaks over the course of the film, but it is a while before we can be confident about what is real and what isn’t: whether his friend, the drunken mischief-maker Igor (Yuri Kolokolnikov), is real and whether Sergey (Ivan Dorn), the struggling writer who browbeats poor Petrov on every point, is a figment of Petrov’s febrile imagination.
    At the start, Petrov’s Flu is very much a sci-fi movie. The city is languishing under an epidemic that arrived accompanied by lights in the sky; Petrova (Chulpan Khamatova), Petrov’s estranged wife, is possessed by a demonic alien force during a library poetry reading; UFO-themed street graffiti comes to life and wiggles across the screen.
    As reality and hallucination part company, however, it becomes something different: a film about parents and children; about creative work, pretension and ambition; and also, strongly, about Russia’s love of science fiction.
    “Petrov’s fever gradually breaks, but it is a while before we can be confident about what is real and what isn’t”
    At its birth, Western science fiction, and especially US science fiction, celebrated adventure and exploration. Russian sci-fi has always been more about finding and building homes in a hostile environment. It is also strongly religious in spirit, and was indeed for many years one of Russia’s very few outlets for spiritual expression.
    The aliens in Russian science fiction invariably offer some form of redemption to a struggling humanity, and Petrov’s Flu is no exception. One of the most affecting scenes in the film is when Petrov, overcome with fear, dashes with his son to a local hospital, only for the pair to be intercepted by a kindly UFO.
    Such are Petrov’s fever dreams, coloured by his space-loving childhood and his adult career drawing comic books. At one point, he remembers his mum and dad decorating a Christmas tree with festive plastic astronauts; at another, Petrova goes on a murderous rampage among the climbing-frame rockets and spaceships of a dilapidated playground.
    Fans of Andrei Tarkovsky, director of 1970s science-fiction classics Solaris and Stalker, will enjoy the nods to key moments in those films. But it would be a mistake, I think, to watch this film for the sci-fi in-jokes. True, Petrov’s Flu is a shocking and funny contribution to Russia’s centuries-old tradition of absurdist art. But it is also a film about people, not to mention an extraordinary evocation of febrile delirium and its assault on the mind.
    In the end, as fantasy and reality separate, what might have seemed to be a disconnected bag of bits (some tender, some shocking, all horribly entertaining) turns out to be a puzzle that, once complete, leaves us exhausted but satisfied. More

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    in Space & Astronomy

    How ‘hot Jupiters’ may get their weirdly tight orbits

    Strange giant planets known as hot Jupiters, which orbit close to their suns, got kicked onto their peculiar paths by nearby planets and stars, a new study finds.

    After analyzing the orbits of dozens of hot Jupiters, a team of astronomers found a way to catch giant planets in the process of getting uncomfortably close to their stars. The new analysis, submitted January 27 to arXiv.org, pins the blame for the weird worlds on gravitational kicks from other massive objects orbiting the same star, many of which destroyed themselves in the process.

    “It’s a pretty dramatic way to create your hot Jupiters,” says Malena Rice, an astrophysicist at Yale University.

    Hot Jupiters have long been mysterious. They orbit very close to their stars, whirling around in a few days or less, whereas all the giant planets in our solar system lie at vast distances from the sun (SN: 6/5/17). To explain the odd planets, astronomers have proposed three main ideas (SN: 5/11/18). Perhaps the hot Jupiters formed next to their stars and stayed put, or maybe they started off farther out and then slowly spiraled inward. In either case, the planets should have circular orbits aligned with their stars’ equators, because the worlds inherited their paths from material in the protoplanetary disks that gave them birth.

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    The new study, though, favors the third idea: Gravitational interactions with another giant planet or a companion star first hurl a Jupiter-sized planet onto a highly elliptical and inclined orbit that brings it close to its star. In some cases, the planet even revolves the wrong way around its star, opposite the way it spins.

    In this scenario, every time the tossed planet sweeps past its sun, the star’s gravity robs the planet of orbital energy. This shrinks the orbit, gradually making it more circular and less inclined, until the planet becomes a hot Jupiter on a small, circular orbit, realigned to be in the same plane as the star’s equator.

    Stars usually circularize a planet’s orbit before they realign it, and cool stars realign an orbit faster than warm stars do. So Rice and her colleagues looked for relationships between the shapes and tilts of the orbits of several dozen hot Jupiters that go around stars of different temperatures.

    Generally speaking, the team found that the hot Jupiters around cool stars tend to be on well-aligned, circular orbits, whereas the hot Jupiters around warm stars are often on orbits that are elongated and off-kilter. Put another way, many of the orbits around warm stars haven’t yet had time to settle down into their final size and orientation. These orbits still bear the marks of having been shaped by gravitational run-ins with neighboring bodies in the system, the team concludes.

    It’s a “simple, elegant argument,” says David Martin, an astrophysicist at Ohio State University in Columbus who was not involved with this study. “They’re presenting the evidence in a new way that helps strengthen” the idea that other massive objects in the same solar system produce hot Jupiters. He suspects this theory probably explains the majority of these planets.

    But it means that innumerable giant worlds have suffered terrible fates. Some of the planets that hurled their brethren close to their stars ended up plunging into those same stars themselves, Rice says. And many other planets got ejected from their solar systems altogether, so today these wayward worlds wander the deep freeze of interstellar space, far from the light of any sun. More