Science

life-threatening-rat-pee-infections-reach-record-levels-in-nyc

Life-threatening rat pee infections reach record levels in NYC

health, Science / /

Epeedemic —

Between 2001 and 2020, there was an average of 3 cases per year. Last year’s tally was 24.

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A rat looks for food while on a subway platform at the Columbus Circle - 59th Street station on May 8, 2023, in New York City.

Enlarge / A rat looks for food while on a subway platform at the Columbus Circle – 59th Street station on May 8, 2023, in New York City.

A life-threatening bacterial infection typically spread through rat urine sickened a record number of people in New York City last year—and this year looks on track for another all-time high, the NYC Department of Health and Mental Hygiene reports.

The infection is leptospirosis, which can cause a range of symptoms, including non-specific ones like fever, headache, chills, muscle aches, vomiting, diarrhea, and cough. But, if left untreated, can become severe, causing kidney failure, liver damage, jaundice, hemorrhage, bloody eyes (conjunctival suffusion), respiratory distress, and potentially death.

The bacteria that causes it—spirochete bacteria of the genus Leptospira—infect rats, which shed the bacteria in their urine. The germs jump to people through direct contact with open wounds or mucous membranes.

New York City has long been in a (mostly losing) war with its rat population, which last year was estimated to be as many as 3 million. Mayor Eric Adams has made fighting the rat population a key initiative, and just last week, the city council proposed the latest strategy to curtail the furry brown rodent’s colony: birth control in the form of salty pellets.

Still, leptospirosis has not been a prime concern from the rats’ mischief until recently. Between 2001 and 2020, the city logged an average of just three leptospirosis cases a year—and some of those were travel related. But, things took a turn during the pandemic when the rat population seemed to boom. From 2021 and 2022, the average shot up to 15. In 2023, there were 24 cases, the highest number of cases ever recorded for a single year. And as of April 10, there have been six cases so far.

That number of cases so far this year is concerning given that Leptospira bacteria are “fragile,” as the NYC health department puts it. They die quickly in the freezing temperatures of winte and the dry heat of summer. Their main time to thrive is in warm, moist conditions. Last year, the months with the most cases were June and October. The health department noted that climate change, which is causing excessive rain and unseasonably warm temperatures, may be partly driving the uptick in cases.

In a health advisory released last week, the city’s health department advised clinicians to be on the lookout for cases, which are treated with common oral antibiotics when mild or intravenous doses when severe. Symptoms typically develop in 5 to 14 days after an exposure, but can show up anywhere from 2 to 30 days.

Of the 98 locally acquired cases that the city has recorded between 2001 and 2023, nearly all were in men (94 percent) and the median age was 50, with a range of 20 to 80 years. Most often, the cases occurred in the Bronx (37), followed by Manhattan (28), Brooklyn (19), Queens (10), and Staten Island (4). Cases presented to clinicians with acute kidney and liver failure and occasionally severe respiratory involvement. Of the 98 cases, six died.

The cases are typically related to living or working environments with rat urine, contaminated soil and water, or materials frequently contaminated with rat urine, such as trash bags or food waste bins. The health department noted that human-to-human transmission is rare.

New York isn’t the only city plagued by leptospirosis cases. Last year, doctors in the Netherlands reported the case of an 18-year-old with jaundiced, bloody eyes, who had developed leptospirosis after falling into a canal that was likely contaminated with rodent urine.

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bodies-found-in-neolithic-pit-were-likely-victims-of-ritualistic-murder

Bodies found in Neolithic pit were likely victims of ritualistic murder

anthropology, Archaeology, cultural evolution, forensic archaeology, neolithic, ritual sacrifice, Science, Uncategorized / /

murder most foul —

One victim may have been hogtied alive in pit, à la Mafia-style ligature strangulation.

–

View taken from the upper part of the 255 storage pit showing the three skeletons, with one individual in a central position

Enlarge / Three female skeletons found in a Neolithic storage pit in France show signs of ritualistic human sacrifice.

. Beeching/Ludes et al., 2024

Archaeologists have discovered the remains of two women in a Neolithic tomb in France, with the positioning of the bodies suggesting they may have been ritualistically murdered by asphyxia or self-strangulation, according to a recent paper published in the journal Science Advances.

(WARNING: graphic descriptions below.)

France’s Rhône Valley is home to several archaeological sites dating to the end of the Middle Neolithic period (between 4250 and 3600/3500 BCE in the region); the sites include various storage silos, broken grindstones, imported ceramics, animal remains (both from communal meals and sacrifices), and human remains deposited in sepulchral pits. Saint-Paul-Trois-Châteaux is one such site.

According to Bertrand Ludes of the Université Paris Cité and his co-authors, the remains of the three women were found in Pit 69, a structure aligned with the summer and winter solstices, as was often the case in ancient agrarian societies. But the body positioning was decidedly atypical. One woman (No. 1), around age 50, was in the center of the pit, reclining on her side with a vase near her head. The other two bodies were just beneath an overhang. Woman No. 2 was on her back, legs bent, with a piece of grindstone placed on her skull. Woman No. 3 was in a prone position, knees bent, with her neck on the thorax of Woman No. 2 and two chunks of grindstone placed on her back.

The unusual positions imply a forceful, deliberate placement, according to the authors, suggesting they died in the pit rather than being tossed in after death. As for the cause of death, the archaeological evidence combined with recent forensic studies suggests “homicidal ligature strangulation” and “forced positional asphyxia”—at least for two of the three women. Woman No. 2, for example, would have struggled to breathe on her back, especially with the weight of Woman No. 3 pressing down on her neck (positional asphyxia), further exacerbated by the placement of the grindstone fragment.

Saint-Paul-Trois-Châteaux and the area surrounding pits 69 and 70.

Enlarge / Saint-Paul-Trois-Châteaux and the area surrounding pits 69 and 70.

Ludes et al., Sci. Adv. 10, eadl3374 (2024)

Woman No. 3’s prone position would mean she also would have struggled to breathe, and the volume of blood pumped by the heart would have sharply decreased, leading to cardiac arrest, a form of positional asphyxia now known as “prone restraint cardiac arrest.” All these clinical terms don’t quite capture the horrifically cruel nature of the manner of death. Given the placement of the woman’s knees—bent at more than a 90-degree angle, making the legs almost vertical—it’s possible she was tied up lying on her stomach, with the ligature connecting her ankles to her neck (similar to being hog-tied). In this position, “self-strangulation becomes inevitable,” the authors wrote, particularly if the mouth and nose are obstructed or there is cervical compression—say, from the strategic placement of grindstone fragments.

This form of torture, known as incaprettamento, has been used by the Italian Mafia, per Ludes et al., often to punish traitors, and dates as far back as the Italian Mesolithic era, “suggesting a highly ancient origin within ceremonial sites.” Sometimes, the victim would be strangled and the body tied up postmortem before the remains were disposed of. Ludes et al. believe Woman No. 3 would probably have been placed in the burial pit and tied up while still alive before self-strangling to death.

  • Reconstruction of the remains, blocked under the overhang of the wall of the storage pit lined with straw.

    Ludes et al., Sci. Adv. 10, eadl3374 (2024)

  • Reconstruction of skeletal remains for Woman No. 2 positioned on her back with bent knees.

    Ludes et al., Sci. Adv. 10, eadl3374 (2024)

  • Reconstruction of skeletal remains for Woman No. 3 in a prone position on her stomach with bent knees. The feet are behind the pelvis/toward the lower back, and the hands are tied behind the back.

    Ludes et al., Sci. Adv. 10, eadl3374 (2024)

  • Mesolithic rock art scene from the Addaura Cave is believed to depict ritual sacrifice by ligature strangulation (bolded figure).

    B. Ludes et al., 2024

In fact, one scene from Mesolithic rock art found in the Addaura Cave in Sicily, Italy, seems to depict a ritual sacrifice by ligature strangulation. There are 11 human figures and the figure of a slain deer. Nine of the human figures form a circle, within which are the other two human figures (male, judging by the erect genitalia). Those figures are shown lying on their stomachs in a prone position, legs folded beneath them, with a rope stretched between their ankles and necks. The erect male genitalia, and one figure drawn with his tongue hanging out, are both signs of strangulation or hanging, per the authors.

It is notoriously difficult to distinguish between a merely violent death and one with ritualistic overtones when it comes to prehistoric remains. So Ludes et al. combed through existing literature for reports of similar cases. They found 20 cases of probable ligature strangulation or positional asphyxia in total across 14 different archaeological sites in Eastern Europe and Catalonia, spanning nearly 2,000 years. The individuals were found lying on their backs or sides, lower limbs flexed until the feet aligned with the pelvis, indicating hip extension. The oldest remains were found at sites in the Czech Republic and date back to between 5400 and 4800 BCE; the three women found at Saint-Paul-Trois-Châteaux are the most recent.

The latter site in particular has elements that “suggest a profound interconnection between religious systems and power structure in an agricultural society,” the authors concluded—namely, various structures aligned with summer and winter solstices indicative of an agricultural cycle and the placement of two women facing the central woman. It’s unclear why the women were sacrificed, the authors added, but such ritualistic sacrifice likely developed across central and southern Europe sometime in the Mesolithic and evolved over the course of two millennia before culminating in the late Middle Neolithic.

Science Advances, 2024. DOI: 10.1126/sciadv.adl3374  (About DOIs).

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climate-damages-by-2050-will-be-6-times-the-cost-of-limiting-warming-to-2°

Climate damages by 2050 will be 6 times the cost of limiting warming to 2°

adaptation, climate change, Earth science, Economics, green, mitigation, Science, Sustainability / /
A worker walks between long rows of solar panels.

Almost from the start, arguments about mitigating climate change have included an element of cost-benefit analysis: Would it cost more to move the world off fossil fuels than it would to simply try to adapt to a changing world? A strong consensus has built that the answer to the question is a clear no, capped off by a Nobel in Economics given to one of the people whose work was key to building that consensus.

While most academics may have considered the argument put to rest, it has enjoyed an extended life in the political sphere. Large unknowns remain about both the costs and benefits, which depend in part on the remaining uncertainties in climate science and in part on the assumptions baked into economic models.

In Wednesday’s edition of Nature, a small team of researchers analyzed how local economies have responded to the last 40 years of warming and projected those effects forward to 2050. They find that we’re already committed to warming that will see the growth of the global economy undercut by 20 percent. That places the cost of even a limited period of climate change at roughly six times the estimated price of putting the world on a path to limit the warming to 2° C.

Linking economics and climate

Many economic studies of climate change involve assumptions about the value of spending today to avoid the costs of a warmer climate in the future, as well as the details of those costs. But the people behind the new work, Maximilian Kotz, Anders Levermann, and Leonie Wenz decided to take an empirical approach. They obtained data about the economic performance of over 1,600 individual regions around the globe, going back 40 years. They then attempted to look for connections between that performance and climate events.

Previous research already identified a number of climate measures—average temperatures, daily temperature variability, total annual precipitation, the annual number of wet days, and extreme daily rainfall—that have all been linked to economic impacts. Some of these effects, like extreme rainfall, are likely to have immediate effects. Others on this list, like temperature variability, are likely to have a gradual impact that is only felt over time.

The researchers tested each factor for lagging effects, meaning an economic impact sometime after their onset. These suggested that temperature factors could have a lagging impact up to eight years after they changed, while precipitation changes were typically felt within four years of climate-driven changes. While this relationship might be in error for some of the economic changes in some regions, the inclusion of so many regions and a long time period should help limit the impact of those spurious correlations.

With the climate/economic relationship worked out, the researchers obtained climate projections from the Coupled Model Intercomparison Project (CMIP) project. With that in hand, they could look at future climates and estimate their economic costs.

Obviously, there are limits to how far into the future this process will work. The uncertainties of the climate models grow with time; the future economy starts looking a lot less like the present, and things like temperature extremes start to reach levels where past economic behavior no longer applies.

To deal with that, Kotz, Levermann, and Wenz performed a random sampling to determine the uncertainty in the system they developed. They look for the point where the uncertainties from the two most extreme emissions scenarios overlap. That occurs in 2049; after that, we can’t expect the past economic impacts of climate to apply.

Kotz, Levermann, and Wenz suggest that this is an indication of warming we’re already committed to, in part because the effect of past emissions hasn’t been felt in its entirety and partly because the global economy is a boat that turns slowly, so it will take time to implement significant changes in emissions. “Such a focus on the near term limits the large uncertainties about diverging future emission trajectories, the resulting long-term climate response and the validity of applying historically observed climate–economic relations over long timescales during which socio-technical conditions may change considerably,” they argue.

Climate damages by 2050 will be 6 times the cost of limiting warming to 2° Read More »

bogus-botox-poisoning-outbreak-spreads-to-9-states,-cdc-says

Bogus Botox poisoning outbreak spreads to 9 states, CDC says

botox, botulism, CDC, health, injection, outbreak, Science / /

botched shots —

All of the case have been in women, nine of whom were hospitalized.

–

A package of counterfeit Botox.

A package of counterfeit Botox.

At least 19 women across nine US states appear to have been poisoned by bogus injections of Botox, the Centers for Disease Control and Prevention reported late Monday.

Nine of the 19 cases—47 percent—were hospitalized and four—21 percent—were treated with botulinum anti-toxin. The CDC’s alert and outbreak investigation follows reports in recent days of botulism-like illnesses linked to shady injections in Tennessee, where officials reported four cases, and Illinois, where there were two. The CDC now reports that the list of affected states also includes: Colorado, Florida, Kentucky, Nebraska, New Jersey, New York, and Washington.

In a separate alert Tuesday, the Food and Drug Administration said that “unsafe, counterfeit” versions of Botox had been found in several states, and the toxic fakes were administered by unlicensed or untrained people and/or in non-medical or unlicensed settings, such as homes or spas. The counterfeit products appeared to have come from an unlicensed source, generally raising the risks that they’re “misbranded, adulterated, counterfeit, contaminated, improperly stored and transported, ineffective and/or unsafe,” the FDA said.

The CDC and the FDA listed the various symptoms that followed injections of the counterfeit Botox, which include: blurred or double vision, drooping eyelids, difficulty swallowing, dry mouth, slurred speech, constipation, incontinence, shortness of breath or difficulty breathing, weakness, and difficulty lifting one’s head. “These symptoms are similar to those seen when botulinum toxin spreads to other parts of the body,” the FDA wrote. Anyone experiencing those symptoms after an injection should go to the emergency room or contact a health care professional.

Botox is a regulated drug containing purified, controlled doses of botulinum toxin, a neurotoxin made by Clostridium bacteria that causes muscle paralysis by blocking a neurotransmitter. It’s often injected into the face to reduce the appearance of wrinkles. The CDC reported that all 19 cases identified so far are in women between the ages of 25 and 59. Eighteen of the 19 specifically reported getting the injections for cosmetic purposes.

But harmful exposure to the toxin—such as from an infection, eating contaminated foods, or use of counterfeit Botox—can cause botulism or at least botulism-like illnesses. In severe cases, botulism can progress to descending, symmetric muscle weakness, full muscle paralysis, and can sometimes be fatal. The CDC reported that some of the people in the outbreak were hospitalized and treated with anti-toxin out of concern that the toxin had spread beyond the injection site. However, the agency noted that five people were specifically tested for botulism, and all tested negative.

In an email to Ars late last week, the CDC recommended that anyone interested in a Botox injection do so using “an FDA-approved product, administered by licensed providers and in licensed settings.” The agency added in its alert Monday: ” If in doubt, don’t get the injection.”

The FDA, meanwhile, provided detailed information on how to ensure your shot of Botox is the real thing. FDA-approved Botox is made by AbbVie, and authentic Botox products come in unit doses of 50, 100, and 200. The outside of the box should say “BOTOX® COSMETIC / onabotulinumtoxinA / for Injection” or “OnabotulinumtoxinA / BOTOX® / for injection,” and it should list the manufacturer as either “Allergan Aesthetics / An AbbVie Company” or “abbvie.” The active ingredient should be listed as “OnabotulinumtoxinA” on the box.

In contrast, some of the counterfeit versions the FDA has tracked down so far were sold in 150-unit doses (not made by AbbVie), only appear to have “Allergan” on the box (not the full manufacturer name), and the active ingredient is displayed as “Botulinum Toxin Type A” instead of  “OnabotulinumtoxinA.” The counterfeit versions also have had non-English language text on the outside of the box and displayed a lot number of C3709C3. Any one of these features is a sign that the product is counterfeit. Images of the counterfeit products from the FDA are below.

Bogus Botox poisoning outbreak spreads to 9 states, CDC says Read More »

studies-reveal-new-clues-to-how-tardigrades-can-survive-intense-radiation

Studies reveal new clues to how tardigrades can survive intense radiation

animals, Biology, Extremophiles, Genetics, proteins, Science, tardigrades / /

It’s in the genes —

Radiation damages their DNA; they’re just able to repair that damage very quickly.

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SEM Micrograph of a tardigrade, commonly known as a water bear

Enlarge / SEM Micrograph of a tardigrade, more commonly known as a “water bear” or “moss piglet.”

Cultura RM Exclusive/Gregory S. Paulson/Getty Images

Since the 1960s, scientists have known that the tiny tardigrade can withstand very intense radiation blasts 1,000 times stronger than what most other animals could endure. According to a new paper published in the journal Current Biology, it’s not that such ionizing radiation doesn’t damage tardigrades’ DNA; rather, the tardigrades are able to rapidly repair any such damage. The findings complement those of a separate study published in January that also explored tardigrades’ response to radiation.

“These animals are mounting an incredible response to radiation, and that seems to be a secret to their extreme survival abilities,” said co-author Courtney Clark-Hachtel, who was a postdoc in Bob Goldstein’s lab at the University of North Carolina at Chapel Hill, which has been conducting research into tardigrades for 25 years. “What we are learning about how tardigrades overcome radiation stress can lead to new ideas about how we might try to protect other animals and microorganisms from damaging radiation.”

As reported previously, tardigrades are micro-animals that can survive in the harshest conditions: extreme pressure, extreme temperature, radiation, dehydration, starvation—even exposure to the vacuum of outer space. The creatures were first described by German zoologist Johann Goeze in 1773. They were dubbed tardigrada (“slow steppers” or “slow walkers”) four years later by Lazzaro Spallanzani, an Italian biologist. That’s because tardigrades tend to lumber along like a bear. Since they can survive almost anywhere, they can be found in lots of places: deep-sea trenches, salt and freshwater sediments, tropical rain forests, the Antarctic, mud volcanoes, sand dunes, beaches, and lichen and moss. (Another name for them is “moss piglets.”)

When their moist habitat dries up, however, tardigrades go into a state known as “tun”—a kind of suspended animation, which the animals can remain in for as long as 10 years. When water begins to flow again, water bears absorb it to rehydrate and return to life. They’re not technically members of the extremophile class of organisms since they don’t so much thrive in extreme conditions as endure; technically, they belong to the class of extremotolerant organisms. But their hardiness makes tardigrades a favorite research subject for scientists.

For instance, a 2017 study demonstrated that tardigrades use a special kind of disordered protein to literally suspend their cells in a glass-like matrix that prevents damage. The researchers dubbed this a “tardigrade-specific intrinsically disordered protein” (TDP). In other words, the cells become vitrified. The more TDP genes a tardigrade species has, the more quickly and efficiently it goes into the tun state.

In 2021, another team of Japanese scientists called this “vitrification” hypothesis into question, citing experimental data suggesting that the 2017 findings could be attributed to water retention of the proteins. The following year, researchers at the University of Tokyo identified the mechanism to explain how tardigrades can survive extreme dehydration: cytoplasmic-abundant heat soluble (CAHS) proteins that form a protective gel-like network of filaments to protect dried-out cells. When the tardigrade rehydrates, the filaments gradually recede, ensuring that the cell isn’t stressed or damaged as it regains water.

When it comes to withstanding ionizing radiation, a 2016 study identified a DNA damage suppressor protein dubbed “Dsup” that seemed to shield tardigrade genes implanted into human cells from radiation damage. However, according to Clark-Hatchel et al., it still wasn’t clear whether this kind of protective mechanism was sufficient to fully account for tardigrades’ ability to withstand extreme radiation. Other species of tardigrade seem to lack Dsup proteins, yet still have the same high radiation tolerance, which suggests there could be other factors at play.

A team of French researchers at the French National Museum of Natural History in Paris ran a series of experiments in which they zapped water bear specimens with powerful gamma rays that would be lethal to humans. They published their results earlier this year in the journal eLife. The French team found that gamma rays did actually damage the tardigrade DNA, much like they would damage human cells. Since the tardigrades survived, this suggested the tardigrades were able to quickly repair the damaged DNA.

Further experiments with three different species (including one that lacks Dsup proteins) revealed the tardigrades were producing very high amounts of DNA repair proteins. They also found a similar uptick of proteins unique to tardigrades, most notably tardigrade DNA damage response protein 1 (TDR1), which seems to protect DNA from radiation. “We found that TDR1 protein interacts with DNA and forms aggregates at high concentration suggesting it may condensate DNA and act by preserving chromosome organization until DNA repair is accomplished,” the authors wrote.

Clark-Hatchel et al. independently arrived at similar conclusions from their own experiments. Taken together, the two studies confirm that this extremely rapid up-regulation of many DNA repair genes in response to exposure to ionizing radiation should be sufficient to explain the creatures’ impressive resistance to that radiation. It’s possible that there is a “synergy between protective and repair mechanisms” when it comes to tardigrade tolerance of ionizing radiation.

That said, “Why tardigrades have evolved a strong IR tolerance is enigmatic given that it is unlikely that tardigrades were exposed to high doses of ionizing radiation in their evolutionary history,” Clark-Hatchel et al. wrote.  They thought there could be a link to the mechanisms that enable tardigrades to survive extreme dehydration, which can also result in damaged DNA. Revisiting data from desiccation experiments did not show nearly as strong an increase in DNA repair transcripts, but the authors suggest that the uptick could occur later in the process, upon rehydration—an intriguing topic for future research.

Current Biology, 2024. DOI: 10.1016/j.cub.2024.03.019  (About DOIs).

eLife, 2024. DOI: 10.7554/eLife.92621.1

Studies reveal new clues to how tardigrades can survive intense radiation Read More »

second-biggest-black-hole-in-the-milky-way-found

Second-biggest black hole in the Milky Way found

astronomy, astrophysics, black holes, Gaia, Science, stars / /
A dark background with a bright point at the end of a curved path, and a small red circle.

Enlarge / The star’s orbit, shown here in light, is influenced by the far more massive black hole, indicated by the red orbit.

As far as black holes go, there are two categories: supermassive ones that live at the center of the galaxies (and we’re unsure about how they got there) and stellar mass ones that formed through the supernovae that end the lives of massive stars.

Prior to the advent of gravitational wave detectors, the heaviest stellar-mass black hole we knew about was only a bit more than a dozen times the mass of the Sun. And this makes sense, given that the violence of the supernova explosions that form these black holes ensures that only a fraction of the dying star’s mass gets transferred into its dark offspring. But then the gravitational wave data started flowing in, and we discovered there were lots of heavier black holes, with masses dozens of times that of the Sun. But we could only find them when they smacked into another black hole.

Now, thanks to the Gaia mission, we have observational evidence of the largest black hole in the Milky Way outside of the supermassive one, with a mass 33 times that of the Sun. And, in galactic terms, it’s right next door at about 2,000 light-years distant, meaning it will be relatively easy to learn more.

Mapping the stars

Although stellar-mass black holes are several times the mass of the Sun, they aren’t really all that heavy in the grand scheme of things. The sorts of stars that tend to leave black holes behind also tend to lead violent existences, spewing a lot of themselves into space before dying. And the supernova that forms the black hole obviously expels a lot of the star’s mass, rather than feeding it into the black hole. It had been thought that these processes set limits on how big a stellar mass black hole could be when it forms.

The discovery of larger black holes through gravitational wave detectors suggested that this wasn’t true. While there are ways for black holes to get bigger after they form—excessive feeding, mergers—it wasn’t clear that these events occurred often enough to explain the frequency of heavy black holes that we were seeing. And detecting them via gravitational waves doesn’t tell us anything about the history of how they got that large.

Which is why the discovery of Gaia BH3 (which is what the research team is using to avoid having to retype Gaia DR3 4318465066420528000 all the time) is so intriguing. The black hole is sitting calmly in a binary system, not doing anything in particular. But we know it’s there due to its gravitational influence.

Gaia is an ESA mission to map the location and movement of many of the Milky Way’s brighter stars by imaging them multiple times from different perspectives. It also gathers basic data on the stars’ light, allowing us to estimate things like age and composition. And, in addition to their movement across the galaxy, Gaia can measure their movement relative to Earth, a method that is useful for the detection of orbital interactions, such as the presence of companion stars or exoplanets.

The Gaia team was busy preparing for the fourth release of the data from the spacecraft and were running validation tests on the software used to detect binary star systems when they stumbled across Gaia BH3. While normally they’d publish its discovery at the same time as the data release, they consider the new object too important to wait: “We took the exceptional step of the publication of this paper based on preliminary data ahead of the official DR4 due to the unique nature of the discovery, which we believe should not be kept from the scientific community until the next release.”

Finding the invisible

Every star in our galaxy is in motion relative to every other. They orbit the center of our galaxy and may have a history that has imparted additional momentum—gravitational interactions with neighbors, having been part of a smaller galaxy that was consumed by the Milky Way, and so on. But that motion only changes on very long time scales. By contrast, any star in an orbit experiences regular changes in its motion in addition to its overall travel through the galaxy. As part of processing its data, the Gaia team attempts to identify both overall motion and any indications that a star is orbiting as part of a binary system.

The star that is orbiting Gaia BH3 is similar in mass to the Sun but shows the sort of periodic wobbles that indicate it’s in a mutual orbit with a companion. The companion itself, however, was completely invisible, which means it is almost certainly a black hole (the Gaia data had already been used to identify black holes this way). And, based on the mass and orbital motion of the visible star, it’s possible to estimate the mass of the invisible companion.

The estimate ended up being 32 solar masses, which is significantly larger than anything else identified in the Gaia dataset. So, the Gaia team wanted to confirm this wasn’t a software issue and used Earth-based telescopes to observe the same system. Three different observatories confirmed it was there, and the resulting mass estimates were slightly larger than those derived from the Gaia data alone: just under 33 solar masses.

Assuming it’s a single object and not two black holes orbiting each other closely, that makes it the largest non-supermassive black hole known in the Milky Way. And it places it in the mass range that had been difficult to explain via formations in supernovae.

Second-biggest black hole in the Milky Way found Read More »

song-lyrics-are-getting-more-repetitive,-angrier

Song lyrics are getting more repetitive, angrier

Human behavior, lyrics, music, Science, songs / /

The song remains the same —

An analysis of 50 years of popular music lyrics reveals a number of trends.

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A female singer gestures towards an enthusiastic crowd.

From ‘80s new wave to ‘90s grunge to the latest pop single, music has changed a lot over the decades. Those changes have come not only in terms of sound, though; lyrics have also evolved as time has passed.

So what has changed about the lyrics we can’t get out of our heads? After analyzing 12,000 English-language pop, rock, rap, R&B, and country songs released between 1970 and 2020, researcher Eva Zangerle of Innsbruck University and her team have found that lyrics have been getting simpler and more repetitive over time. This trend is especially evident in rap and rock, but it applies to other genres as well. Another thing Zangerle’s team discovered is that lyrics tend to be more personal and emotionally charged now than they were over 50 years ago.

Know the words…

“Just as literature can be considered a portrayal of society, lyrics also provide a reflection of a society’s shifting norms, emotions, and values over time,” the researchers wrote in a study recently published in Scientific Reports.

That’s why Zangerle created a dataset to find out the different ways in which lyrics have changed. She and her colleagues used the virtual music encyclopedia Genius, which also provides release year and genre information. From the lyric dataset she created, the team pulled data having to do with the structure, language, emotion, and complexity of songs. Five genres—pop, rock, rap, R&B, and country—were chosen because they are genres with the most lyrics that were popular on streaming platform last.fm.

There were two types of analyses done on the music. The first looked for the lyrical trends that were most prevalent for each release year, while the second went deeper into online views of lyrics, characteristics of lyrics (such as emotion), and release year. The researchers obtained the play count from last.fm and the lyrics view count from Genius.

How often people view the lyrics is unexpectedly important. Unlike play counts of songs, this stat shows how important lyrics are despite the popularity (or lack thereof) of the song or genre.

…and the meaning

What can lyrics tell us about different genres and eras? Results for the first analysis showed that certain characteristics are most important across genres, including repeated lines, choruses, and emotional language. The genres in which emotion was most important were country and R&B.

Repeated lines increased over the decades in all genres analyzed, and later lyrics contain more choruses than earlier ones. These increases are further proof that songs have become simpler and more repetitive since the ‘70s.

Lyrics were also more personal and angrier across all genres studied. Personal lyrics were identified by the number of personal pronouns, which especially increased in rap and pop, while rock and R&B saw moderate increases and country stayed nearly the same. Anger and other negative emotions (as expressed through words associated with these emotions) also increased across genres. Rap had the highest increase here, especially in anger, while country showed the lowest increase. Positive emotions decreased in pop and rock, while they increased somewhat in rap.

When looking at the results from the second analysis, Zangerle noticed that lyric views were higher for older rock songs than newer ones, and vice versa for country, which had lower view counts for older songs and higher view counts for new songs. This means that the popularity of country lyrics has increased over time in comparison to rock. Listening count had no relationship to this, meaning interest in the sound of a song was not related to interest in its lyrics.

Through the decades, it seems that music has gotten simpler, more repetitive, and more emotional—especially angrier—and more personal. The study didn’t look into what events and societal changes might have influenced this trend, but the researchers still had some sociological insights. They think pop is all about record sales and what’s hot from one moment to the next, while the preference for older rock songs shows that the main audience of rock is middle-class and against commercialism. Emotionally charged words could also convey feelings toward shifts in society.

The researchers “believe that the role of lyrics has been understudied and that our results can be used to further study and monitor cultural artifacts and shifts in society,” the study said.

Scientific Reports, 2024.  DOI: 10.1038/s41598-024-55742-x

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Sleeping more flushes junk out of the brain

Biology, brain, Neuroscience, Science, sleep / /

Better sleep on it —

Rhythmic activity during sleep may get fluids in the brain moving.

–

Abstract image of a pink brain against a blue background.

As if we didn’t have enough reasons to get at least eight hours of sleep, there is now one more. Neurons are still active during sleep. We may not realize it, but the brain takes advantage of this recharging period to get rid of junk that was accumulating during waking hours.

Sleep is something like a soft reboot. We knew that slow brainwaves had something to do with restful sleep; researchers at the Washington University School of Medicine in St. Louis have now found out why. When we are awake, our neurons require energy to fuel complex tasks such as problem-solving and committing things to memory. The problem is that debris gets left behind after they consume these nutrients. As we sleep, neurons use these rhythmic waves to help move cerebrospinal fluid through brain tissue, carrying out metabolic waste in the process.

In other words, neurons need to take out the trash so it doesn’t accumulate and potentially contribute to neurodegenerative diseases. “Neurons serve as master organizers for brain clearance,” the WUSTL research team said in a study recently published in Nature.

Built-in garbage disposal

Human brains (and those of other higher organisms) evolved to have billions of neurons in the functional tissue, or parenchyma, of the brain, which is protected by the blood-brain barrier.

Everything these neurons do creates metabolic waste, often in the form of protein fragments. Other studies have found that these fragments may contribute to neurodegenerative diseases such as Alzheimer’s.

The brain has to dispose of its garbage somehow, and it does this through what’s called the glymphatic system (no, that’s not a typo), which carries cerebrospinal fluid that moves debris out of the parenchyma through channels located near blood vessels. However, that still left the questions: What actually powers the glymphatic system to do this—and how? The WUSTL team wanted to find out.

To see what told the glymphatic system to dump the trash, scientists performed experiments on mice, inserting probes into their brains and planting electrodes in the spaces between neurons. They then anesthetized the mice with ketamine to induce sleep.

Neurons fired strong, charged currents after the animals fell asleep. While brain waves under anesthesia were mostly long and slow, they induced corresponding waves of current in the cerebrospinal fluid. The fluid would then flow through the dura mater, the outer layer of tissue between the brain and the skull, taking the junk with it.

Just flush it

The scientists wanted to be sure that neurons really were the force that pushed the glymphatic system into action. To do that, they needed to genetically engineer the brains of some mice to nearly eliminate neuronal activity while they were asleep (though not to the point of brain death) while leaving the rest of the mice untouched for comparison.

In these engineered mice, the long, slow brain waves seen before were undetectable. As a result, the fluid was no longer pushed to carry metabolic waste out of the brain. This could only mean that neurons had to be active in order for the brain’s self-cleaning cycle to work.

Furthermore, the research team found that there were fluctuations in the brain waves of the un-engineered mice, with slightly faster waves thought to be targeted at the debris that was harder to remove (at least, this is what the researchers hypothesized). It is not unlike washing a plate and then needing to scrub slightly harder in places where there is especially stubborn residue.

The researchers also found out why previous experiments produced different results. Because the flushing out of cerebrospinal fluid that carries waste relies so heavily on neural activity, the type of anesthetic used mattered—anesthetics that inhibit neural activity can interfere with the results. Other earlier experiments worked poorly because of injuries caused by older and more invasive methods of implanting the monitoring hardware into brain tissues. This also disrupted neurons.

“The experimental methodologies we used here largely avoid acute damage to the brain parenchyma, thereby providing valuable strategies for further investigations into neural dynamics and brain clearance,” the team said in the same study.

Now that neurons are known to set the glymphatic system into motion, more attention can be directed towards the intricacies of that process. Finding out more about the buildup and cleaning of metabolic waste may contribute to our understanding of neurodegenerative diseases. It’s definitely something to think about before falling asleep.

Nature, 2024.  DOI: 10.1038/s41586-024-07108-6

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why-do-some-people-always-get-lost?

Why do some people always get lost?

navigation, Science, syndication / /

I don’t know where I’m going —

Experience may matter more than innate ability when it comes to sense of direction.

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Scientists are homing in on how navigation skills develop.

Enlarge / Scientists are homing in on how navigation skills develop.

Knowable Magazine (CC BY-ND)

Like many of the researchers who study how people find their way from place to place, David Uttal is a poor navigator. “When I was 13 years old, I got lost on a Boy Scout hike, and I was lost for two and a half days,” recalls the Northwestern University cognitive scientist. And he’s still bad at finding his way around.

The world is full of people like Uttal—and their opposites, the folks who always seem to know exactly where they are and how to get where they want to go. Scientists sometimes measure navigational ability by asking someone to point toward an out-of-sight location—or, more challenging, to imagine they are someplace else and point in the direction of a third location—and it’s immediately obvious that some people are better at it than others.

“People are never perfect, but they can be as accurate as single-digit degrees off, which is incredibly accurate,” says Nora Newcombe, a cognitive psychologist at Temple University who coauthored a look at how navigational ability develops in the 2022 Annual Review of Developmental Psychology. But others, when asked to indicate the target’s direction, seem to point at random. “They have literally no idea where it is.”

While it’s easy to show that people differ in navigational ability, it has proved much harder for scientists to explain why. There’s new excitement brewing in the navigation research world, though. By leveraging technologies such as virtual reality and GPS tracking, scientists have been able to watch hundreds, sometimes even millions, of people trying to find their way through complex spaces, and to measure how well they do. Though there’s still much to learn, the research suggests that to some extent, navigation skills are shaped by upbringing.

Nurturing navigation skills

The importance of a person’s environment is underscored by a recent look at the role of genetics in navigation. In 2020, Margherita Malanchini, a developmental psychologist at Queen Mary University of London, and her colleagues compared the performance of more than 2,600 identical and nonidentical twins as they navigated through a virtual environment to test whether navigational ability runs in families. It does, they found—but only modestly. Instead, the biggest contributor to people’s performance was what geneticists call the “nonshared environment”—that is, the unique experiences each person accumulates as their life unfolds. Good navigators, it appears, are mostly made, not born.

A remarkable, large-scale experiment led by Hugo Spiers, a cognitive neuroscientist at University College London, gave researchers a glimpse at how experience and other cultural factors might influence wayfinding skills. Spiers and his colleagues, in collaboration with the telecom company T-Mobile, developed a game for cellphones and tablets, Sea Hero Quest, in which players navigate by boat through a virtual environment to locate a series of checkpoints. The game app asked participants to provide basic demographic data, and nearly 4 million worldwide did so. (The app is no longer accepting new participants except by invitation of researchers.)

Through the app, the researchers were able to measure wayfinding ability by the total distance each player traveled to reach all the checkpoints. After completing some levels of the game, players also had to shoot a flare back toward their point of origin—a dead-reckoning test analogous to the pointing-to-out-of-sight-locations task. Then Spiers and his colleagues could compare players’ performance to the demographic data.

Several cultural factors were associated with wayfinding skills, they found. People from Nordic countries tended to be slightly better navigators, perhaps because the sport of orienteering, which combines cross-country running and navigation, is popular in those countries. Country folk did better, on average, than people from cities. And among city-dwellers, those from cities with more chaotic street networks such as those in the older parts of European cities did better than those from cities like Chicago, where the streets form a regular grid, perhaps because residents of grid cities don’t need to build such complex mental maps.

Why do some people always get lost? Read More »

how-new-tech-is-making-geothermal-energy-a-more-versatile-power-source

How new tech is making geothermal energy a more versatile power source

Energy, geothermal power, Science, syndication / /

Energy rising —

Geothermal has moved beyond being confined to areas with volcanic activity.

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The Nesjavellir Geothermal Power Station. Geothermal power has long been popular in volcanic countries like Iceland, where hot water bubbles from the ground.

Enlarge / The Nesjavellir Geothermal Power Station. Geothermal power has long been popular in volcanic countries like Iceland, where hot water bubbles from the ground.

Gretar Ívarsson/Wikimedia Commons

Glistening in the dry expanses of the Nevada desert is an unusual kind of power plant that harnesses energy not from the sun or wind, but from the Earth itself.

Known as Project Red, it pumps water thousands of feet into the ground, down where rocks are hot enough to roast a turkey. Around the clock, the plant sucks the heated water back up to power generators. Since last November, this carbon-free, Earth-borne power has been flowing onto a local grid in Nevada.

Geothermal energy, though it’s continuously radiating from Earth’s super-hot core, has long been a relatively niche source of electricity, largely limited to volcanic regions like Iceland where hot springs bubble from the ground. But geothermal enthusiasts have dreamed of sourcing Earth power in places without such specific geological conditions—like Project Red’s Nevada site, developed by energy startup Fervo Energy.

Such next-generation geothermal systems have been in the works for decades, but they’ve proved expensive and technologically difficult, and have sometimes even triggered earthquakes. Some experts hope that newer efforts like Project Red may now, finally, signal a turning point, by leveraging techniques that were honed in oil and gas extraction to improve reliability and cost-efficiency.

The advances have garnered hopes that with enough time and money, geothermal power—which currently generates less than 1 percent of the world’s electricity, and 0.4 percent of electricity in the United States—could become a mainstream energy source. Some posit that geothermal could be a valuable tool in transitioning the energy system off of fossil fuels, because it can provide a continuous backup to intermittent energy sources like solar and wind. “It’s been, to me, the most promising energy source for a long time,” says energy engineer Roland Horne of Stanford University. “But now that we’re moving towards a carbon-free grid, geothermal is very important.”

A rocky start

Geothermal energy works best with two things: heat, plus rock that is permeable enough to carry water. In places where molten rock sizzles close to the surface, water will seep through porous volcanic rock, warm up and bubble upward as hot water, steam, or both.

If the water or steam is hot enough—ideally at least around 300 degrees Fahrenheit—it can be extracted from the ground and used to power generators for electricity. In Kenya, nearly 50 percent of electricity generated comes from geothermal. Iceland gets 25 percent of its electricity from this source, while New Zealand gets about 18 percent and the state of California, 6 percent.

Some natural geothermal resources are still untapped, such as in the western United States, says geologist Ann Robertson-Tait, president of GeothermEx, a geothermal energy consulting division at the oilfield services company SLB. But by and large, we’re running out of natural, high-quality geothermal resources, pushing experts to consider ways of extracting geothermal energy from areas where the energy is much harder to access. “There’s so much heat in the Earth,” Robertson-Tait says. But, she adds, “much of it is locked inside rock that isn’t permeable.”

The Lardarello plant in the Tuscany region of Italy was the first geothermal power plant in the world. It was completed in 1913.

Enlarge / The Lardarello plant in the Tuscany region of Italy was the first geothermal power plant in the world. It was completed in 1913.

Tapping that heat requires deep drilling and creating cracks in these non-volcanic, dense rocks to allow water to flow through them. Since 1970, engineers have been developing “enhanced geothermal systems” (EGS) that do just that, applying methods similar to the hydraulic fracturing—or fracking—used to suck oil and gas out of deep rocks. Water is pumped at high pressure into wells, up to several miles deep, to blast cracks into the rocks. The cracked rock and water create an underground radiator where water heats before rising to the surface through a second well. Dozens of such EGS installations have been built in the United States, Europe, Australia, and Japan—most of them experimental and government-funded—with mixed success.

Famously, one EGS plant in South Korea was abruptly shuttered in 2017 after having probably caused a 5.5-magnitude earthquake; fracking of any kind can add pressure to nearby tectonic faults. Other issues were technological—some plants didn’t create enough fractures for good heat exchange, or fractures traveled in the wrong direction and failed to connect the two wells.

Some efforts, however, turned into viable power plants, including several German and French systems built between 1987 and 2012 in the Rhine Valley. There, engineers made use of existing fractures in the rock.

But overall, there just hasn’t been enough interest to develop EGS into a more reliable and lucrative technology, says geophysicist Dimitra Teza of the energy research institute Fraunhofer IEG in Karlsruhe, Germany, who helped develop some of the Rhine Valley EGS systems. “It has been quite tough for the industry.”

Geothermal electricity has long been limited to volcanic regions where underground heat is easily accessible. But new kinds of power plants are making it possible to derive geothermal heat elsewhere in the world.

Enlarge / Geothermal electricity has long been limited to volcanic regions where underground heat is easily accessible. But new kinds of power plants are making it possible to derive geothermal heat elsewhere in the world.

How new tech is making geothermal energy a more versatile power source Read More »

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Rocket Report: Delta IV’s grand finale; Angara flies another dummy payload

rocket report, Science, Space / /
The Angara A5 rocket launched this week from Vostochny for the first time.

Enlarge / The Angara A5 rocket launched this week from Vostochny for the first time.

Roscosmos

Welcome to Edition 6.39 of the Rocket Report! The big news this week came from United Launch Alliance, and the final mission of its Delta IV Heavy rocket. Both Stephen and I had thoughts about this launch, which is bittersweet, and we expressed them in stories linked below. It’s been a little less than 20 years since this big rocket debuted, and interesting to think how very much the launch industry has changed since then.

As always, we welcome reader submissions, and if you don’t want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets as well as a quick look ahead at the next three launches on the calendar.

Rocket Lab to reuse flight tank. On Wednesday Rocket Lab said it is returning a previously flown Electron rocket first stage tank to the production line for the first time in preparation for reflying the stage. The company characterized this as a “significant” milestone as it seeks to make Electron the world’s first reusable small rocket. This stage was successfully launched and recovered as part of the ‘Four of a Kind’ mission earlier this year on January 31.

Iterating a path to reuse … The stage will now undergo final fit out and rigorous qualification for reuse. “Our key priority in pushing this stage back into the standard production flow for the first time is to ensure our systems and qualification processes are fit for accepting pre-flown boosters at scale,” said Rocket Lab founder and CEO Peter Beck. “If this stage successfully passes and is accepted for flight, we’ll consider opportunities for reflying it in the new year.” (submitted by Ken the Bin)

Virgin Orbit IP for sale on LinkedIn. In a post this week on the social networking site LinkedIn, former Virgin Orbit chief executive Dan Hart said that the Virgin Orbit IP library is being made available for licensing. “The flight-proven LauncherOne IP can accelerate launch and hypersonic system development schedules by years, and enable significant cost savings,” Hart wrote. “The innovative designs can also offer component/subsystem providers immediate product line expansion.”

Yours for a low, low price … The IP library includes all manner of goodies, including an FAA-approved flight termination system, the Newton 3 and Newton 4 engines, avionics, structures, and more. Price for access to all IP is $3 million for a nonexclusive license, Hart said. I have no idea whether that’s a good price or not.

The easiest way to keep up with Eric Berger’s space reporting is to sign up for his newsletter, we’ll collect his stories in your inbox.

Virgin Galactic countersues Boeing. Virgin Galactic has filed a countersuit against Boeing over a project to develop a new mothership aircraft, arguing in part that Boeing performed poorly, Space News reports. The suit, filed last week in the US District Court for the Central District of California, comes two weeks after Boeing filed suit against Virgin Galactic, alleging that Virgin refused to pay more than $25 million in invoices on the project and misappropriated trade secrets.

Citing Boeing’s own record … The dispute revolves around a project announced in 2022 to develop a new aircraft that would replace Virgin’s existing VMS Eve as an air-launch platform. Virgin, in its suit, claims that Boeing performed “shoddy and incomplete” work on the initial phases of the project. “Boeing’s failures with respect to its agreement with Virgin Galactic are consistent with Boeing’s record of poor quality control and mismanagement,” the complaint states. (submitted by EllPeaTea)

Navy awards contract to Ursa Major. The rocket propulsion startup said Monday it has signed a contract with the United States Navy to develop and test solid fuel rocket engines in an effort to develop a next generation of solid rocket motor for the Navy’s standard missile program, Reuters reports. The agreement is part of a series of prototype engine contracts being awarded by the US Navy as it seeks to expand the industrial base for manufacturing them.

Broadening the US supplier base … The deal comes as the Navy is seeing a surge in missile demand due to the ongoing conflicts in Gaza and Yemen and the war in Ukraine. “Our new approach to manufacturing solid rocket motors allows Ursa Major to quickly develop high-performing motors at scale, driving volume and cost efficiencies to address this critical national need,” said Ursa Major Founder Joe Laurienti. (submitted by Ken the Bin)

Rocket Report: Delta IV’s grand finale; Angara flies another dummy payload Read More »

a-supernova-caused-the-boat-gamma-ray-burst,-jwst-data-confirms

A supernova caused the BOAT gamma ray burst, JWST data confirms

astronomy, astrophysics, B.O.A.T., Gamma ray bursts, nucleosynthesis, Physics, Science, Webb telescope / /

Still the BOAT —

But astronomers are puzzled by the lack of signatures of expected heavy elements.

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Artist's visualization of GRB 221009A showing the narrow relativistic jets — emerging from a central black hole — that gave rise to the brightest gamma ray burst yet detected.

Enlarge / Artist’s visualization of GRB 221009A showing the narrow relativistic jets—emerging from a central black hole—that gave rise to the brightest gamma-ray burst yet detected.

Aaron M. Geller/Northwestern/CIERA/ ITRC&DS

In October 2022, several space-based detectors picked up a powerful gamma-ray burst so energetic that astronomers nicknamed it the BOAT (Brightest Of All Time). Now they’ve confirmed that the GRB came from a supernova, according to a new paper published in the journal Nature Astronomy. However, they did not find evidence of heavy elements like platinum and gold one would expect from a supernova explosion, which bears on the longstanding question of the origin of such elements in the universe.

As we’ve reported previously, gamma-ray bursts are extremely high-energy explosions in distant galaxies lasting between mere milliseconds to several hours. There are two classes of gamma-ray bursts. Most (70 percent) are long bursts lasting more than two seconds, often with a bright afterglow. These are usually linked to galaxies with rapid star formation. Astronomers think that long bursts are tied to the deaths of massive stars collapsing to form a neutron star or black hole (or, alternatively, a newly formed magnetar). The baby black hole would produce jets of highly energetic particles moving near the speed of light, powerful enough to pierce through the remains of the progenitor star, emitting X-rays and gamma rays.

Those gamma-ray bursts lasting less than two seconds (about 30 percent) are deemed short bursts, usually emitting from regions with very little star formation. Astronomers think these gamma-ray bursts are the result of mergers between two neutron stars, or a neutron star merging with a black hole, comprising a “kilonova.” That hypothesis was confirmed in 2017 when the LIGO collaboration picked up the gravitational wave signal of two neutron stars merging, accompanied by the powerful gamma-ray bursts associated with a kilonova.

The October 2022 gamma-ray burst falls into the long category, lasting over 300 seconds. GRB 221009A triggered detectors aboard NASA’s Fermi Gamma-ray Space Telescope, the Neil Gehrels Swift Observatory, and Wind spacecraft, among others, just as gamma-ray astronomers had gathered for an annual meeting in Johannesburg, South Africa. The powerful signal came from the constellation Sagitta, traveling some 1.9 billion years to Earth.

Several papers were published last year reporting on the analytical results of all the observational data. Those findings confirmed that GRB 221009A was indeed the BOAT, appearing especially bright because its narrow jet was pointing directly at Earth. But the various analyses also yielded several surprising results that puzzled astronomers. Most notably, a supernova should have occurred a few weeks after the initial burst, but astronomers didn’t detect one, perhaps because it was very faint, and thick dust clouds in that part of the sky were dimming any incoming light.

Swift’s X-ray Telescope captured the afterglow of GRB 221009A about an hour after it was first detected.

Enlarge / Swift’s X-ray Telescope captured the afterglow of GRB 221009A about an hour after it was first detected.

NASA/Swift/A. Beardmore (University of Leicester)

That’s why Peter Blanchard of Northwestern University and his fellow co-authors decided to wait six months before undertaking their own analysis, relying on data collected during the GRB’s later phase by the Webb Space Telescope’s Near Infrared Spectrograph. They augmented that spectral data with observations from ALMA (Atacama Large Millimeter/Submillimeter Array) in Chile so they could separate light from the supernova and the GRB afterglow. The most significant finding was the telltale signatures of key elements like calcium and oxygen that one would expect to find with a supernova.

Yet the supernova wasn’t brighter than other supernovae associated with less energetic GRBs, which is puzzling. “You might expect that the same collapsing star producing a very energetic and bright GRB would also produce a very energetic and bright supernova,” said Blanchard. “But it turns out that’s not the case. We have this extremely luminous GRB, but a normal supernova.” The authors suggest that this might have something to do with the shape and structure of the relativistic jet, which was much narrower than other GRB jets, resulting in a more focused and brighter beam of light.

The data held another surprise for astronomers. The only confirmed source of heavy elements in the universe to date is the merging of binary neutron stars. But per Blanchard, there are far too few neutron star mergers to account for the abundance of heavy elements, so there must be another source. One hypothetical additional source is a rapidly spinning massive star that collapses and explodes into a supernova. Alas, there was no evidence of heavy elements in the JWST spectral data regarding the BOAT.

“When we confirmed that the GRB was generated by the collapse of a massive star, that gave us the opportunity to test a hypothesis for how some of the heaviest elements in the universe are formed,” said Blanchard. “We did not see signatures of these heavy elements, suggesting that extremely energetic GRBs like the BOAT do not produce these elements. That doesn’t mean that all GRBs do not produce them, but it’s a key piece of information as we continue to understand where these heavy elements come from. Future observations with JWST will determine if the BOAT’s ‘normal’ cousins produce these elements.”

Nature Astronomy, 2024. DOI: 10.1038/s41550-024-02237-4  (About DOIs).

A supernova caused the BOAT gamma ray burst, JWST data confirms Read More »