Hubble watches how a giant planet grows

 NASA's Hubble Space Telescope is giving astronomers a rare look at a Jupiter-sized, still-forming planet that is feeding off material surrounding a young star.

"We just don't know very much about how giant planets grow," said Brendan Bowler of the University of Texas at Austin. "This planetary system gives us the first opportunity to witness material falling onto a planet. Our results open up a new area for this research."

Though over 4,000 exoplanets have been cataloged so far, only about 15 have been directly imaged to date by telescopes. And the planets are so far away and small, they are simply dots in the best photos. The team's fresh technique for using Hubble to directly image this planet paves a new route for further exoplanet research, especially during a planet's formative years.

This huge exoplanet, designated PDS 70b, orbits the orange dwarf star PDS 70, which is already known to have two actively forming planets inside a huge disk of dust and gas encircling the star. The system is located 370 light-years from Earth in the constellation Centaurus.

"This system is so exciting because we can witness the formation of a planet," said Yifan Zhou, also of the University of Texas at Austin. "This is the youngest bona fide planet Hubble has ever directly imaged." At a youthful five million years, the planet is still gathering material and building up mass.

Hubble's ultraviolet light (UV) sensitivity offers a unique look at radiation from extremely hot gas falling onto the planet. "Hubble's observations allowed us to estimate how fast the planet is gaining mass," added Zhou.

The UV observations, which add to the body of research about this planet, allowed the team to directly measure the planet's mass growth rate for the first time. The remote world has already bulked up to five times the mass of Jupiter over a period of about five million years. The present measured accretion rate has dwindled to the point where, if the rate remained steady for another million years, the planet would only increase by approximately an additional 1/100th of a Jupiter-mass.

Zhou and Bowler emphasize that these observations are a single snapshot in time -- more data are required to determine if the rate at which the planet is adding mass is increasing or decreasing. "Our measurements suggest that the planet is in the tail end of its formation process."

The youthful PDS 70 system is filled with a primordial gas-and-dust disk that provides fuel to feed the growth of planets throughout the entire system. The planet PDS 70b is encircled by its own gas-and-dust disk that's siphoning material from the vastly larger circumstellar disk. The researchers hypothesize that magnetic field lines extend from its circumplanetary disk down to the exoplanet's atmosphere and are funneling material onto the planet's surface.

"If this material follows columns from the disk onto the planet, it would cause local hot spots," Zhou explained. "These hot spots could be at least 10 times hotter than the temperature of the planet." These hot patches were found to glow fiercely in UV light.

These observations offer insights into how gas giant planets formed around our Sun 4.6 billion years ago. Jupiter may have bulked up on a surrounding disk of infalling material. Its major moons would have also formed from leftovers in that disk.

A challenge to the team was overcoming the glare of the parent star. PDS 70b orbits at approximately the same distance as Uranus does from the Sun, but its star is more than 3,000 times brighter than the planet at UV wavelengths. As Zhou processed the images, he very carefully removed the star's glare to leave behind only light emitted by the planet. In doing so, he improved the limit of how close a planet can be to its star in Hubble observations by a factor of five.

Read more at Science Daily

Was North America populated by 'stepping stone' migration across Bering Sea?

Ice agFor thousands of years during the last ice age, generations of maritime migrants paddled skin boats eastward across shallow ocean waters from Asia to present-day Alaska. They voyaged from island to island and ultimately to shore, surviving on bountiful seaweeds, fish, shellfish, birds and game harvested from coastal and nearshore biomes. Their island-rich route was possible due to a shifting archipelago that stretched almost 900 miles from one continent to the other.

A new study from the University of Kansas in partnership with universities in Bologna and Urbino, Italy, documents the newly named Bering Transitory Archipelago and then points to how, when and where the first Americans may have crossed. The authors' stepping-stones hypothesis depends on scores of islands that emerged during the last ice age as sea level fell when ocean waters were locked in glaciers and later rose when ice sheets melted. The two-part study, just published in the open-access journal Comptes Rendus Geoscience, may answer what writer Fen Montaigne calls "one of the greatest mysteries of our time . . . when humans made the first bold journey to the Americas."

The "stepping-stones" idea hinges on retrospective mapping of sea levels while accounting for isostacy -- deformation of the Earth's crust due to the changing depth and weight of ice and water, reaching its greatest extreme during the Last Glacial Maximum about 20,500 years ago.

"We digitally discovered a geographic feature of considerable size that had never been properly documented in scientific literature," said principal author Jerome Dobson, professor emeritus of geography at KU. "We named it the Bering Transitory Archipelago; it existed from about 30,000 years ago through 8,000 years ago. When we saw it, we immediately thought, 'Wow, maybe that's how the first Americans came across.' And, in fact, everything we've tested seems to bear that out -- it does seem to be true."

For more than a decade, researchers have pondered a mystery within a mystery. Mitochondrial DNA indicates that migrants were isolated somewhere for up to 15,000 years on their way over from Asia to North America. The Beringian Standstill Hypothesis arises from the fact that today Native American DNA is quite different from Asian DNA, a clear indication of genetic drift of such magnitude that it can only have happened over long periods of time in nearly complete isolation from the Asian source population. The Bering Transitory Archipelago provides a suitable refugium with internal connectivity and outward isolation.

Dobson said people crossing the Bering Sea probably didn't have sails but could have been experienced in paddling skin boats like the kayaks and umiaks that Inuits use today.

"They probably traveled in small groups," he said, "either from Asia or islands off the coast of Asia. Some maritime people are known to have existed 27,000 years ago on northern Japanese islands. They probably were maritime people -- not just living on islands, but actually practicing maritime culture, economy and travel."

Dobson recently received the American Geographical Society's Cullum Geographical Medal (the same gold medal that Neil Armstrong won for flying to the moon and Rachel Carson won for writing "Silent Spring"). He named and continuously champions "aquaterra" -- all lands that were exposed and inundated repeatedly during the Late Pleistocene ice ages -- thus creating a zone of archeological promise scattered offshore from all coastal regions around the globe.

Recently, Dobson and co-authors Giorgio Spada of the University of Bologna and Gaia Galassi of Urbino University "Carlo Bo" applied an improved Glacial Isostatic Adjustment model to nine global choke points, meaning isthmuses and straits that have funneled transport and trade throughout history. Significant human migrations are known to have occurred across some of them, including "Beringia" -- all portions of the Bering Sea that were exposed before, during and after the Last Glacial Maximum.

"These Italian ocean scientists read my 'Aquaterra' paper and took it upon themselves to refine the boundaries of aquaterra for the whole world at coarse resolution and for Beringia itself at fine resolution," Dobson said. "Later we agreed to join forces and tackle those nine global choke points. At the end of that study, we suddenly spotted these islands in the Bering Sea, and that became our focus. This had an immediate potential because it could be a real game-changer in terms of all sciences understanding how migration worked in the past. We found startling results in certain other choke points and have begun analyzing them as well."

In Beringia, the three investigators contend, this action produced a "conveyor belt" of islands that rose from the sea and fell back again, pushing bands of people eastward. "The first islands to appear were just off the coast of Siberia," the KU researcher said. "Then islands appeared ever eastward. Most likely migrants kept expanding eastward, too, generally to islands within view and an easy paddle away."

By 10,500 years ago, when the Bering Strait itself first appeared, almost all islands in the west had submerged. Only three islands remained, and paddling distances had increased accordingly. Thus, occupants were forced to evacuate, and they faced a clear choice: return to Asia, which they knew to be populated and may even have left due to population pressures and resource constraints, or paddle east to less known territory, perhaps less populated islands with ample resources.

To fully confirm the idea set forth in the new paper, Dobson said researchers from many fields will need to collaborate as one geographer and two ocean scientists have done here.

Read more at Science Daily

Global glacier retreat has accelerated

 An international research team including scientists from ETH Zurich has shown that almost all the world's glaciers are becoming thinner and losing mass' and that these changes are picking up pace. The team's analysis is the most comprehensive and accurate of its kind to date.

Glaciers are a sensitive indicator of climate change -- and one that can be easily observed. Regardless of altitude or latitude, glaciers have been melting at a high rate since the mid-20th century. Until now, however, the full extent of ice loss has only been partially measured and understood. Now an international research team led by ETH Zurich and the University of Toulouse has authored a comprehensive study on global glacier retreat, which was published online in Nature on 28 April. This is the first study to include all the world's glaciers -- around 220,000 in total -- excluding the Greenland and Antarctic ice sheets. The study's spatial and temporal resolution is unprecedented -- and shows how rapidly glaciers have lost thickness and mass over the past two decades.

Rising sea levels and water scarcity What was once permanent ice has declined in volume almost everywhere around the globe. Between 2000 and 2019, the world's glaciers lost a total of 267 gigatonnes (billion tonnes) of ice per year on average -- an amount that could have submerged the entire surface area of Switzerland under six metres of water every year. The loss of glacial mass also accelerated sharply during this period. Between 2000 and 2004, glaciers lost 227 gigatonnes of ice per year, but between 2015 and 2019, the lost mass amounted to 298 gigatonnes annually. Glacial melt caused up to 21 percent of the observed rise in sea levels during this period -- some 0.74 millimetres a year. Nearly half of the rise in sea levels is attributable to the thermal expansion of water as it heats up, with meltwaters from the Greenland and Antarctic ice sheets and changes in terrestrial water storage accounting for the remaining third.

Among the fastest melting glaciers are those in Alaska, Iceland and the Alps. The situation is also having a profound effect on mountain glaciers in the Pamir mountains, the Hindu Kush and the Himalayas. "The situation in the Himalayas is particularly worrying," explains Romain Hugonnet, lead author of the study and researcher at ETH Zurich and the University of Toulouse. "During the dry season, glacial meltwater is an important source that feeds major waterways such as the Ganges, Brahmaputra and Indus rivers. Right now, this increased melting acts as a buffer for people living in the region, but if Himalayan glacier shrinkage keeps accelerating, populous countries like India and Bangladesh could face water or food shortages in a few decades." The findings of this study can improve hydrological models and be used to make more accurate predictions on a global and local scales -- for instance, to estimate how much Himalayan glacier meltwater one can anticipate over the next few decades.

To their surprise, the researchers also identified areas where melt rates slowed between 2000 and 2019, such as on Greenland's east coast and in Iceland and Scandinavia. They attribute this divergent pattern to a weather anomaly in the North Atlantic that caused higher precipitation and lower temperatures between 2010 and 2019, thereby slowing ice loss. The researchers also discovered that the phenomenon known as the Karakoram anomaly is disappearing. Prior to 2010, glaciers in the Karakoram mountain range were stable -- and in some cases, even growing. However, the researchers' analysis revealed that Karakoram glaciers are now losing mass as well.

Study based on stereo satellite images As a basis for the study, the research team used imagery captured on board NASA's Terra satellite, which has been orbiting the Earth once every 100 minutes since 1999 at an altitude of nearly 700 kilometres. Terra is home to ASTER, a multispectral imager with two cameras that record pairs of stereo images, allowing researchers to create high-resolution digital elevation models of all the world's glaciers. The team used the full archive of ASTER images to reconstruct a time series of glacial elevation, which enabled them to calculate changes in the thickness and mass of the ice over time.

Lead author Romain Hugonnet is a doctoral student at ETH Zurich and the University of Toulouse. He worked on this project for nearly three years and spent 18 months analysing the satellite data. To process the data, the researchers used a supercomputer at the University of Northern British Columbia. Their findings will be included in the next Assessment Report of the United Nations Intergovernmental Panel on Climate Change (IPCC), which is due to be published later this year. "Our findings are important on a political level. The world really needs to act now to prevent the worst-case climate change scenario," says co-author Daniel Farinotti, head of the glaciology group at ETH Zurich and the Swiss Federal Institute for Forest, Snow and Landscape Research WSL.

Read more at Science Daily

Greta Thunberg and Fridays For Future, from global myth to local mobilization

In 2019 the climate movement experienced an unprecedented growth in its mobilization capacity and its political and media impact. The success of the movement is closely linked to the figure of Greta Thunberg and the global impact of her discourse and the "Fridays for Future" movement in hundreds of cities around the world.

A study by Silvia Díaz-Pérez, Roger Soler-i-Martí and Mariona Ferrer-Fons, members of the UPF JOVIS research group of the Department of Communication, analyses the activist's speeches and messages on social networks and their legitimization through her personal story, and it also looks into the "Fridays for Future" movement in Barcelona, based on Twitter and Instagram posts. The research was based on a project that has received funding from UPF's Planetary Wellbeing call.

Greta Thunberg creates a framework for collective action that is present in her speeches and posts on social networks and has great strength and a great impact

"What it analyses, therefore the article is how Greta Thunberg creates a framework for collective action that is present in her speeches and posts on social networks and has great strength and a great impact because it is accompanied by a personal story that follows the monomyth structure," Roger Soler-Martí explains. In mythology and art, the monomyth takes the shape of the archetypal journey of the hero who achieves such status by overcoming dangers and adventures after a calling or suffering an event that takes him from an ordinary world to a mythical world.

"Fridays for Future," an international, principally student movement that protests to demand action against global warming and climate change, gained momentum when the activist Greta Thunberg began to demonstrate in front of Swedish Parliament, in August 2018. The "Fridays for Future" movement, despite its diversity, serves Greta Thunberg as an agent of mobilization and resonance.

The "Fridays for Future" movement, despite its diversity, serves as an agent of mobilization and resonance in the activist's frame

The authors studied how Thunberg's global frame is incorporated locally, for which they focused on the case of "Fridays for Future" in Barcelona via Twitter and Instagram content from its creation (February 2019) until the outbreak of the covid-19 pandemic.

The results show a clear influence of the activist in the discourse of local movements and among their followers. As Soler-i-Martí, co-author of the work explains, "despite the rejection of personalist leaderships and despite the particular characteristics of the local group, the activist's global framework is very present in the discourse broadcast on "Fridays for Future" Barcelona social networks."

The construction of the frames in social movements arise from two-way dialogue between the global and the local dimensions

And Soler-i-Martí adds, "In addition, the study reveals how the experience of local groups of the movement also influenced the evolution of Thunberg's discourse, which has changed over time, incorporating new actors and strategies. This element highlights how the construction of the frames in social movements arise from two-way dialogue between the global and the local dimensions."

The analysis provides empirical evidence of the importance of global and local dynamics in social movements on the Internet and highlights that the use of the basic elements of Thunberg's frame lead messages from the local "Fridays for Future" Barcelona movement to have a greater impact on social networks among its followers.

Read more at Science Daily

Equipping crop plants for climate change

Biologists at Ludwig-Maximilians-Universitaet (LMU in Munich) have significantly enhanced the tolerance of blue-green algae to high light levels -- with the aid of artificial evolution in the laboratory.

Sunlight, air and water are all that cyanobacteria (more commonly known as blue-green algae), true algae and plants need for the production of organic (i.e. carbon-based) compounds and molecular oxygen by means of photosynthesis. Photosynthesis is the major source of building blocks for organisms on Earth. However, too much sunlight reduces the efficiency of photosynthesis because it damages the 'solar panels', i.e. the photosynthetic machineries of cyanobacteria, algae and plants. A team of researchers led by LMU biologist Dario Leister has now used "artificial laboratory evolution" to identify mutations that enable unicellular cyanobacteria to tolerate high levels of light. The long-term aim of the project is to find ways of endowing crop plants with the ability to cope with the effects of climate change.

The cyanobacteria used in the study were derived from a strain of cells that were used to grow at low levels of light. "To enable them to emerge from the shadows, so to speak, we exposed these cells to successively higher light intensities," says Leister. In an evolutionary process based on mutation and selection, the cells adapted to the progressive alteration in lighting conditions -- and because each cell divides every few hours, the adaptation process proceeded at a far higher rate than would have been possible with green plants. To help the process along, the researchers increased the natural mutation rate by treating cells with mutagenic chemicals and irradiating them with UV light. By the end of the experiment, the surviving blue-green algae were capable of tolerating light intensities that were higher than the maximal levels that can occur on Earth under natural conditions.

To the team's surprise, most of the over 100 mutations that could be linked to increased tolerance to bright light resulted in localized changes in the structures of single proteins. "In other words, the mutations involved primarily affect the properties of specific proteins rather than altering the regulatory mechanisms that determine how much of any given protein is produced," Leister explains. As a control, the team then introduced the genes for two of the altered proteins, which affect photosynthesis in different ways, into non-adapted strains. -- And in each case, they found that the change indeed enabled the altered cells to tolerate higher light intensities than the progenitor strain.

Enhancing the tolerance of crop plants to higher or fluctuating light intensities potentially provides a means of increasing productivity, and is of particular interest against the background of ongoing global climate change. "Application of genetic engineering techniques to plant breeding has so far concentrated on quantitative change -- on making more or less of a specific protein," says Leister. "Our strategy makes qualitative change possible, allowing us to identify new protein variants with novel functions. Insofar as these variants retain their function in multicellular organisms, it should be possible to introduce them into plants."

 From Science Daily

Human behavior must be factored into climate change analyses

A new Cornell University-led study examines how temperature affects fishing behavior and catches among inland fisher households in Cambodia, with important implications for understanding climate change.

The research, which used household surveys, temperature data and statistical models, revealed that when temperatures rise, people fish less often. At the same time, the study's authors indirectly found that stocks of fish and other aquatic foods also rise with temperatures, leading to slightly larger catches each time peopled fished. Without careful analysis, it would appear that overall fish catches appear unchanged annually, when in fact, more nuanced dynamics are at play.

The study highlights why it's necessary when studying changing environmental conditions to include human behavior along with ecosystem responses; both are key variables when considering how climate change affects rural livelihoods, food production and food access.

The paper, "Fishers' Response to Temperature Change Reveals the Importance of Integrating Human Behavior in Climate Change Analysis," published April 30 in the journal Science Advances.

"This study underscores the importance of pulling human behavior into climate change modeling," said Kathryn Fiorella, an assistant professor in the Department of Population Medicine and Diagnostic Sciences and Master of Public Health Program in the College of Veterinary Medicine. "To accurately predict the impacts of climate change, we need to know about the effects on ecological systems, and also the effects on people who use them."

In the study, Fiorella and colleagues used data provided by partner organization WorldFish, which collected survey data every two months over three years for households in Cambodia, which has the world's highest per-capita consumption of inland fish. WorldFish collected information on how often people fished, how much time they spent when they fished, and what method they used.

The researchers used remotely sensed temperature data over the same three-year period, which revealed a range of 24 to 31 degrees Celsius (75 to 88 degrees Fahrenheit). The researchers also controlled for rainfall and flooding.

"The temperatures in the range of the study compare to regional climate projections in the area, which suggest around a 1.5 to 2.5 degrees Celsius [2.7 to 4.5 F] temperature rise above the average of 28 degrees Celsius [82.4 F]," Fiorella said. "What we observed is in range for what we might expect under climate change scenarios."

The researchers found time spent fishing per outing and the gear choices were not affected by temperature, but fewer people fished as temperatures rose.

They also analyzed fish catch. It turns out that, with effort holding constant, fish catch per outing went up as temperatures rose, which meant the ecosystem became a little more productive when it was warmer. The same pattern was true for other aquatic animals, like frogs or snakes, and aquatic plants. However, without factoring in effects of temperature on human behavior, it might have looked like temperature had no effect.

The researchers suspect that fishing frequency declined as temperatures rose due to competing interests. "These households have a suite of different activities they are engaged in at the same time," Fiorella said, noting many of them are rice farmers or run small businesses. At the same time, heat may also be a factor, she added.

Fiorella added that large swaths of the population migrate to cities or nearby countries for work, and these dynamics could be pulling them away from fishing.

"Ultimately," she said, "understanding both ecosystem responses and people's responses to temperature is going to be fundamental to understanding how climate change affects people who are directly reliant on the natural resources for their food and income."

Read more at Science Daily

Natural immunity to malaria provides clues to potential therapies

WEHI researchers have identified how natural human antibodies can block malaria parasites from entering red blood cells, potentially indicating how new protective therapies could be developed against this globally significant disease.

The research provides greater insight into how antibodies block the entry of Plasmodium vivax malaria parasites into young red blood cells called reticulocytes. It builds on an earlier discovery that the P. vivax latches onto the transferrin receptor 1 (TfR1) to enter cells.

The research, led by Associate Professor Wai-Hong Tham and PhD student Li-Jin Chan from WEHI, alongside Professor Christopher King from Case Western University, US, was published in Nature Communications.

At a glance
 

• By examining antibodies from people with a history of malaria infection, researchers observed that naturally occurring antibodies can block Plasmodium vivax from latching onto transferrin receptor 1 on reticulocytes.
• One way the antibodies work is by preventing parasite proteins from getting close enough to the cell to allow parasite entry.
• The discovery opens up new avenues for developing antibody-based therapies for malaria.
   
• Shedding light on pathogen-blocking antibodies
   
• Plasmodium vivax is the most widespread malaria parasite in the world, and the predominant cause of malaria in the vast majority of countries outside Africa. It is also the main parasite responsible for recurrent malaria infections.

The malaria parasite is a complex single-celled organism, with diverse proteins that help it to invade red blood cells, reproduce and spread. Adhesins on the surface of the parasite are key-like proteins that 'unlock' cells, allowing the parasite to enter.

Previous research studies in Papua New Guinea, Thailand and Brazil showed antibodies against P. vivax adhesins were correlated with protection against infection and disease, Associate Professor Tham said.

"We wanted to understand how these human antibodies in natural infection block the parasite from getting in. By extracting and examining antibodies from people who have had P. vivax infections, we identified the different ways human antibodies against P. vivax work. One of these ways, is by stopping the parasite adhesins from getting too close to the reticulocyte membrane, denying the parasite entry," she said.

This discovery opens the door to potentially preventing not only P. vivax malaria, but also P. falciparum malaria, another significant cause of deaths globally.

"Although this was a vivax study, we believe the implications are that a broadly neutralising antibody could be created to target both P. vivax and P. falciparum malaria infections," Associate Professor Tham said.

Improving detection of relapsing malaria

WEHI Professor Ivo Mueller said beyond understanding how antibodies can block infection, there was also a crucial need to understand the development of immunity and how this could be used to detect P. vivax infections in endemic populations.

"We are currently using this information to develop diagnostic tests that will be used in the field to identify and treat people with hidden vivax infection in their livers and spleens. This is a key step towards eliminating malaria, by preventing silently infected people reinfecting their communities," he said.

Read more at Science Daily

Genetics, not the intrauterine environment, controls abnormal development

Yale researchers have shown that developmental abnormalities, including those that lead to pregnancy loss and autism, are controlled by the genetics of the fetus and placenta -- and not the mother's intrauterine environment.

The findings are reported in the April 28 online edition of the journal Placenta.

One out of every 33 children is diagnosed with a birth defect each year in the United States, according to the Centers for Disease Control and Prevention (CDC). This translates into one baby born every 4 ½ minutes -- or 120,000 per year.

"Mothers often feel that they are responsible for these defects. But it's not their fault," said senior author Dr. Harvey Kliman, a research scientist in the Department of Obstetrics, Gynecology & Reproductive Services at the Yale School of Medicine. "This new research points to the genetics of these children as being the most important cause."

For the study, Kliman's team examined placental data for nearly 50 sets of identical and non-identical twins. The researchers found that abnormal cell growths called trophoblast inclusions (TIs) which are markers for many developmental abnormalities, occurred with similar frequency in identical twins, while non-identical twins showed a markedly different TI count.

Identical twins share the same DNA sequence; non-identical twins share half of their DNA sequence. The researchers found that identical twins often had the same number of TIs or were within one of having the same TI count. Non-identical twins had TI counts that were, on average, different by four or five.

"This work suggests that developmental abnormalities are much more likely to be due to the genetics of the child, and not the mother's fault," Kliman said.

Lead author Julia Katz, a former Yale undergraduate who is now a medical student at Hofstra University, provided the inspiration for the study.

Katz and her brother, Jesse, who was born underweight and with several congenital abnormalities, are non-identical twins. "I had a lot of guilt, growing up, about why my twin had certain conditions that I didn't," Katz said. "I think mothers also tend to blame themselves."

Katz approached Kliman after a Yale lecture and asked him what causes babies to be born undersized. The conversation led to a discussion about developmental abnormalities and Katz's desire to seek out information about her and her twin's genetics -- including looking at her own placental slides from birth.

It also led Kliman, Katz, and co-author Parker Holzer, a graduate student in the Yale Department of Statistics and Data Science, to conduct the new study.

"Julia's need to resolve this burden is what propelled our study," Kliman said. "Hopefully, this finding will help many other people, as well."

Read more at Science Daily

Not just for finding planets: Exoplanet-hunter TESS telescope spots bright gamma-ray burst

NASA has a long tradition of unexpected discoveries, and the space program's TESS mission is no different. SMU astrophysicist and her team have discovered a particularly bright gamma-ray burst using a NASA telescope designed to find exoplanets -- those occurring outside our solar system -- particularly those that might be able to support life.

It's the first time a gamma-ray burst has been found this way.

Gamma-ray bursts are the brightest explosions in the universe, typically associated with the collapse of a massive star and the birth of a black hole. They can produce as much radioactive energy as the sun will release during its entire 10-billion-year existence.

Krista Lynne Smith, an assistant professor of physics at Southern Methodist University, and her team confirmed the blast -- called GRB 191016A -- happened on Oct. 16 and also determined its location and duration. A study on the discovery has been published in The Astrophysical Journal.

"Our findings prove this TESS telescope is useful not just for finding new planets, but also for high-energy astrophysics," said Smith, who specializes in using satellites like TESS (Transiting Exoplanet Survey Satellite) to study supermassive black holes and gas that surrounds them. Such studies shed light on the behavior of matter in the deeply warped spacetime around black holes and the processes by which black holes emit powerful jets into their host galaxies.

Smith calculated that GRB 191016A had a peak magnitude of 15.1, which means it was 10,000 times fainter than the faintest stars we can see with the naked eyes.

That may sound quite dim, but the faintness has to do with how far away the burst occurred. It is estimated that light from GRB 191016A's galaxy had been travelling 11.7 billion years before becoming visible in the TESS telescope.

Most gamma ray bursts are dimmer -- closer to 160,000 times fainter than the faintest stars.

The burst reached its peak brightness sometime between 1,000 and 2,600 seconds, then faded gradually until it fell below the ability of TESS to detect it some 7000 seconds after it first went off.

This gamma-ray burst was first detected by a NASA's satellite called Swift-BAT, which was built to find these bursts. But because GRB 191016A occurred too close to the moon, the Swift-BAT couldn't do the necessary follow-up it normally would have to learn more about it until hours later.

NASA's TESS happened to be looking at that same part of the sky. That was sheer luck, as TESS turns its attention to a new strip of the sky every month.

While exoplanet researchers at a ground-base for TESS could tell right away that a gamma-ray burst had happened, it would be months before they got any data from the TESS satellite on it. But since their focus was on new planets, these researchers asked if any other scientists at a TESS conference in Sydney, Australia were interested in doing more digging on the blast.

Smith was one of the few high-energy astrophysics specialists there at that time and quickly volunteered.

"The TESS satellite has a lot of potential for high-energy applications, and this was too good an example to pass up," she said. High-energy astrophysics studies the behavior of matter and energy in extreme environments, including the regions around black holes, powerful relativistic jets, and explosions like gamma-ray bursts.

TESS is an optical telescope that collects light curves on everything in its field of view, every half hour. Light curves are a graph of light intensity of a celestial object or region as a function of time. Smith analyzed three of these light curves to be able to determine how bright the burst was.

She also used data from ground-based observatories and the Swift gamma-ray satellite to determine the burst's distance and other qualities about it.

Read more at Science Daily

Risk of developmental difficulties remains high among children born early

 Children born preterm (before 37 weeks of pregnancy) remain at high risk of developmental difficulties that can affect their behaviour and ability to learn, finds a study published by The BMJ today.

These difficulties were found not only in children born extremely preterm (22-26 weeks) but also in those born very and moderately preterm (between 27 and 34 weeks), say researchers.

Survival of preterm babies has increased worldwide. Children born early often have developmental issues, but studies have mainly focused on those born extremely preterm (22-26 weeks' gestation) and less is known about children born very and moderately preterm (27-34 weeks' gestation).

Given how important it is to identify children most at risk of developmental difficulties, researchers in France set out to describe neurodevelopment among children born before 35 weeks compared with children born at full term.

Their findings are based on 3,083 French children aged 5½ born after 24-26, 27-31, and 32-34 weeks gestation who were taking part in the EPIPAGE-2 study (designed to investigate outcomes of preterm children over the past 15 years) and a comparison group of 600 children born at full term.

Neurodevelopmental outcomes such as cerebral palsy, sensory impairments (blindness and deafness), and brain function (cognition), as well as behavioural difficulties and movement disorders, were assessed using recognised tests.

To further assess the family and social burden of prematurity, measures such as the need for extra support at school, visits to a psychiatrist, speech therapist or physiotherapist, and parental concerns about development, were also recorded.

After adjusting for other potentially influential factors, the researchers found that rates of neurodevelopmental disabilities increased as gestational age decreased.

For example, among the 3,083 children assessed, rates of severe to moderate neurodevelopmental disabilities were 28%, 19% and 12% and rates of mild disabilities were 39%, 36%, and 34% among children born at 24-26, 27-31 and 32-34 weeks, respectively.

Assistance at school was used by 27%, 14% and 7% of children born at 24-26, 27-31, and 32-34 weeks, respectively. And about half of children born at 24-26 weeks received at least one developmental intervention which fell to 26% for those born at 32-34 weeks.

Behaviour was the concern most commonly reported by parents.

Rates of neurodevelopmental disabilities were also higher in families with low socioeconomic status.

This is an observational study, so can't establish cause, and the researchers point to some limitations that may have affected their results. However, by assessing a wide range of developmental and behavioural issues, they were better able to reflect the complexity of difficulties faced by these children and their families.

As such, they say their findings indicate that preterm birth "continues to pose a large burden for families, healthcare, and educational systems."

Although rates of severe to moderate neurodevelopmental disabilities decreased with increasing gestational age, they point out that around 35% of the moderately to extremely preterm born children had mild disabilities requiring special care or educational services.

And a considerable proportion of parents had concerns about their child's development, particularly about behaviour, which warrant attention, they add.

Read more at Science Daily