Serpens Nebula: A row of jets appears as red streaks in the upper left corner
NASA, ESA, CSA, STScI, Klaus Pontoppidan (NASA-JPL), Joel Green (STScI)
Astronomers have captured a star alignment: New images from the James Webb Space Telescope (JWST) show jets emanating from a young star lining up in a straight line, finally proving a phenomenon that has long been suspected but never before been observed.
As a giant gas cloud collapses and begins to form stars, its rotation accelerates — similar to how an ice skater pulls their arms in closer to their body to spin faster. This rotation causes a disk of dust and gas to form around the young star at the cloud's center, feeding the cloud itself.
Strong magnetic fields in the disk send jets of material along the star's rotation axis, which can be used to measure the young star's rotation direction. The JWST image of the Serpens Nebula, about 1,400 light-years away, shows 12 baby stellar clumps. All the jets are pointing in roughly the same direction..
“Astronomers have long assumed that when clouds collapse and stars form, the stars tend to rotate in the same direction,” he said. Klaus Pontoppidan At NASA's Jet Propulsion Laboratory in California statement“But we've never seen it so directly before.”
The new observations suggest that these stars all inherit their rotation from the same long string of gas. Over time, this rotation may change as the stars interact with each other and other space objects. This is evident from the fact that another group of younger, possibly older, stars in the same image of the Ophiuchus Nebula do not have aligned jets.
“Put that phone away!” Most parents have yelled something similar to this at their children, usually resulting in a shocked look on the child’s face.
In recent years, the spread of smartphones and social media has led us to spend more time in front of screens. Children are no exception. The COVID-19 pandemic has led to a significant increase in children’s screen time due to lockdowns and school closures.
There are many frightening claims about excessive screen time for children and teens: that it harms their mental health, leading to depression, eating disorders and even suicide; that it cuts into time they could be spending on socializing and exercise, making them feel lonely and less physically fit; and more. In short, the fear is that spending too much time on digital devices is ruining our children’s lives, with the tech companies who design the apps that keep us hooked being complicit. It’s no wonder that governments around the world are considering restricting screen time for under-18s.
Yet a closer look at the evidence does not support this overwhelmingly negative view. This does not mean that the tech giants are harmless and that further regulation is not needed. But it does mean that we need to think more carefully about what healthy screen time looks like for young people, and how we can make the online world the most accessible to them. So here is your guide to what we actually know about the impact of screens and social media.
One thing is clear in this complex field: children and young people, like the rest of us, spend a lot of time in front of screens.
Studies indicate that adolescents with internet addiction exhibit alterations in brain chemistry that can contribute to further addictive behaviors.
In a study published in PLOS Mental Health, researchers analyzed fMRI studies to explore how brain regions interact in individuals with internet addiction.
The findings revealed changes in neural network activity in the brains of young individuals, with increased activity during rest and reduced connectivity in areas involved in cognitive functions like memory and decision-making.
These alterations were linked to addictive behaviors, mental health issues, cognitive abilities, and physical coordination in adolescents.
The study reviewed 12 prior studies involving 237 young individuals diagnosed with internet addiction from 2013 to 2023.
Recent surveys show that nearly half of British teens feel addicted to social media platforms.
Lead researcher Max Zhang from the University of London emphasized the vulnerability of adolescents to internet addiction due to developmental changes during this crucial stage.
The study suggests that early intervention for internet addiction is essential to mitigate negative impacts on adolescent behavior and development.
Experts recommend targeted treatments focused on specific brain regions or therapies to combat internet addiction symptoms.
Parental education plays a crucial role in preventing internet addiction, enabling better management of screen time and impulsive online behaviors.
Lead author Eileen Li from GOS ICH emphasizes the importance of setting boundaries on internet usage and being mindful of its effects on mental and social well-being.
Criticism has been directed at Mark Zuckerberg’s meta by Britain’s terror watchdog for reducing the minimum age for WhatsApp users from 16 to 13. This move is seen as “unprecedented” and is expected to expose more teenagers to extremist content.
Jonathan Hall KC expressed concerns about the increased access to unregulated content, such as terrorism and sexual exploitation, that meta may not be able to monitor.
Jonathan Hall described the decision as “unusual”.
According to Mr. Hall, the use of end-to-end encryption by WhatsApp has made it difficult for meta to remove harmful content, contributing to the exposure of younger users to unregulated materials.
He highlighted the vulnerability of children to terrorist content, especially following a spike in arrests among minors. This exposure may lead vulnerable children to adopt extremist ideologies.
WhatsApp implemented the age adjustment in the UK and EU in February, aligning with global standards and implementing additional safeguards.
Despite the platform’s intentions, child safety advocates criticized the move, citing a growing need for tech companies to prioritize child protection.
The debate over end-to-end encryption and illegal content on messaging platforms has sparked discussions on online safety regulations, with authorities like Ofcom exploring ways to address these challenges.
The government has clarified that any intervention by Ofcom regarding content scanning must meet privacy and accuracy standards and be technically feasible.
In a related development, Meta announced plans to introduce end-to-end encryption to Messenger and is expected to extend this feature to Instagram.
This Hubble image shows a star-forming region containing giant young blue stars in the Tarantula Nebula. Image credits: NASA/ESA/STScI/Francesco Paresce, INAF-IASF Bologna/Robert O'Connell, UVA/SOC-WFC3/ESO.
“We believe the ULLYSES project is revolutionary and will have an impact across astrophysics, from exoplanets to the influence of massive stars on the evolution of galaxies, to understanding the early stages of the evolving universe. ” said Dr. Julia Roman-Duval, leader of the ULLYSES implementation team. She is an astronomer at the Space Telescope Science Institute.
“Apart from the specific purpose of research, stellar data can also be used in the field of astrophysics in ways we cannot yet imagine.”
Dr. Romain Duval and her colleagues studied 220 stars and combined their observations with information on 275 stars from the Hubble archive.
The study also includes data from some of the world's largest and most powerful ground-based telescopes and X-ray space telescopes.
The ULLYSES dataset consists of stellar spectra and includes information about each star's temperature, chemical composition, and rotation.
One of the star types being studied under ULLYSES is an ultra-hot, massive blue star.
They are a million times brighter than the Sun and glow intensely in ultraviolet light that can be easily detected by Hubble. Their spectra contain important information for diagnosing the speed of powerful winds.
The wind drives the evolution of galaxies, producing galactic seeds with the elements necessary for life. These elements are cooked in the star's fusion reactor and injected into space as the star dies.
ULLYSES targeted blue stars in nearby galaxies that are deficient in elements heavier than helium and hydrogen.
“Observations of Ulises are a stepping stone to understanding the first stars and their winds in the universe and how they influence the evolution of young host galaxies,” said Dr. Romain Duval.
Another category of stars in the ULLYSES survey are young stars with less mass than the Sun.
Although it is cooler and redder than the Sun, during its formative years it emits large amounts of high-energy radiation, including bursts of ultraviolet and X-rays.
As they are still growing, they are collecting material from the surrounding planet-forming disks of dust and gas.
Hubble's spectra contain important diagnostic information about the mass-gaining process, including the amount of energy this process releases into the surrounding planet-forming disk and nearby environment.
Intense ultraviolet radiation from young stars influences the evolution of these disks as they form planets and the potential habitability of newborn planets.
The target star is located in a star-forming region near the Milky Way.
The ULLYSES concept was designed by a panel of experts with the aim of using Hubble to provide a conventional set of stellar observations.
“ULLYSES was originally conceived as an observation program using Hubble's high-sensitivity spectrometer,” said Dr. Roman Duval.
“However, this research was greatly enhanced by community-driven complementary observations in collaboration with other ground-based and space-based observatories.”
“By covering such a wide area, astronomers can study the lives of stars in unprecedented detail and develop a more comprehensive picture of the properties of these stars and how they affect their environments. It becomes possible to draw.”
A new image from the NASA/ESA Hubble Space Telescope shows a jet emerging from the cocoon of the multistar system FS Tau.
This Hubble image shows the multistar system FS Tau about 450 light-years away in the constellation Taurus. Image credit: NASA / ESA / K. Stapelfeldt, NASA Jet Propulsion Laboratory / Gladys Kober, NASA / Catholic University.
FS Tau It is located about 450 light years away in the constellation Taurus.
The system is part of the Taurus-Auriga region, a collection of dark molecular clouds that is home to many newly formed young stars.
FS Tau, also known as HH 157 or TIC 58437437, is only about 2.8 million years old, making it an extremely young star system.
FS Tau is a multi-star system consisting of FS Tau A, a bright star-like object near the center of the image, and FS Tau B, a bright object on the far right hidden by a dark vertical dust lane. ''' said the Hubble astronomer.
“The young object is surrounded by gently illuminated gas and dust in this stellar nursery.”
“FS Tau B is a protostar surrounded by a protoplanetary disk. A protoplanetary disk is a pancake-like collection of dust and gas left over from star formation that eventually coalesces to form a planet. It will be.”
“A thick lane of dust seen almost head-on separates what is believed to be the illuminated surface of the flared disk.”
“FS Tau B is probably T TauriAlthough nuclear fusion has not yet begun, it is a type of young variable star that is beginning to evolve into a hydrogen-fueled star similar to the Sun. ”
“Protostars glow because of the thermal energy released when the gas clouds from which they formed collapse, and from the accretion of material from nearby gas and dust.”
“Variable stars are a type of star whose brightness changes significantly over time.”
“FS Tau A itself is a Tauri T binary system, consisting of two stars orbiting each other,” the researchers added.
“Protostars are known to emit fast-moving columns of energetic material called jets, and FS Tau B provides a striking example of this phenomenon.”
“Protostars are the source of the unusual, asymmetric, double-sided jets that appear blue here.”
“Their asymmetric structure may be due to differences in the rate at which mass is ejected from the object.”
“Herbig halo objects form when jets of ionized gas emitted by young stars collide at high speed with nearby clouds of gas and dust, forming bright nebular patches.”
A colony of black garden ants in a nest with several eggs, pupae, larvae and a large queen bee
Nick Bruning/Shutterstock
When a black ant queen notices that her young are sick, she eats them before the disease spreads to other parts of the nest.
Cannibal queens may not win the “Mother of the Year” award, but research suggests this strategy could be an effective way to protect the kingdom. The findings provide insight into the evolution of “filial cannibalism,'' the practice of parents consuming their children.
Ants and other colony-dwelling social insects can prevent the spread of disease by forcing workers to self-isolate when they become sick and by eliminating infected nestmates. These “social immunity” obligations are well known, he writes. Flynn Bizzell and christopher pull at Oxford University. But since the ant queen starts colonies alone, how does she protect herself from disease as she builds and grows her nest?
To find out, Bizell and Puru collected newly mated black ants (Lasius Niger) took the queen to the laboratory. Once the ants had laid eggs and started building nests, the researchers removed the larvae from the queen and exposed some to deadly ant spores. Metahydium A fungus that infects wild ant nests. After a period of time during which these larvae developed a potentially fatal infection, the researchers returned all of the larvae to their mothers, even though they were not yet contagious.
The queen ate 92 percent of the diseased larvae, but only 6 percent of the larvae were uninfected, indicating that the queen was able to detect infection and intervene. Failure to catch the infection can have dire consequences. When the researchers exposed the colonies to the carcasses of highly infectious larvae that had sprouted spore-producing fungi, all the larvae died. And even after spraying the carcasses with an acidic antibacterial toxin, only 20 percent of the queens survived.
Despite these risks, queen bees that feed on infected larvae appear to avoid harm. Researchers suggest that queen bees may be ingesting their own antimicrobial toxins to make their intestines hostile to fungal spores. Based on this conclusion, they Observation of worker ants before they swallow the poison The team then observed the queen bee tending to the openings of her venom glands.
“If the queen gets infected and dies, the colony dies as well,” he says. sebastian stockmeyer She is at the University of Tennessee, Knoxville, as she is the only one with the ability to reproduce. Therefore, it makes sense that evolved strategies to deal with disease would emphasize queen survival.
There are other benefits to eating sick babies as well. The researchers found that queens that ate sick offspring laid 55% more eggs than queens that did not, suggesting that they recycled these caloric resources. The researchers argue that this benefit and the elimination of disease risk could indicate how filial cannibalism evolves in some species.
Joel Meunier Researchers at the University of Tours in France believe that offspring that hatch after their older siblings are eaten may have immune systems that better protect against fungal infections. If so, proving this may reveal the “double benefit” of filial cannibalism for both mother and offspring.
This finding suggests that there is overlap in the behaviors needed to care for young and prevent disease in young colonies. As a result, Bizell and Pule argue that workers' disease prevention behaviors may have evolved from common parental care found in many types of insects.
These worm-like creatures secrete nutritious milk from their butts to nourish their hatchlings. This is the first known example of an amphibian feeding its young in this way.
American paper wasp (Siphonops anulatus) is a legless, egg-laying amphibian found on dark, moist forest floors throughout South America. It can reach up to 45 centimeters in length, with a deep blue cylindrical body surrounded by white grooves.
American paper wasps are born with spoon-shaped teeth. They use these to feed on their mother's skin, which is rich in lipids and proteins.
“But this skin nourishment only happens once a week,” he says carlos jared At the Butantan Institute in São Paulo, Brazil. That's not enough food to maintain the young's growth rate, he says, with some cubs growing 150 percent larger within the first week of life.
To find out where their extra nutrition is coming from, Jared and his colleagues filmed 16 female ringed wasps and their hatchlings.
The researchers observed the newly hatched chicks wriggling around the edges of their mother's body several times a day, often nibbling or sticking their heads into the rear opening known as the vent.
Closer examination of the footage showed that droplets of a milk-like substance were frequently spilled into the vent openings, suggesting that the chicks were actively feeding on it.
Analysis of the milk revealed that it contained fat and carbohydrates. “These carbohydrates are very important,” say team members Pedro Maillo-Fontanathe Butantan Research Institute also provides hatchlings with the energy they need to grow.
The researchers also discovered that touch and sound signals from hatchlings stimulate milk production in the mother's oviducts, or glands within the fallopian tubes.
Some paper wasps that give birth to live offspring secrete nutritious fluids for the fetus inside the mother's body, while amphibians produce fluids to nourish their offspring outside the body, Mailho-Fontana said. This is the first time that this has been found to be the case.
“The paper wasp is a real surprise box,” says Jared. “They are very secretive and live in an underground world that is different from the one above. They adapt to a world that is completely different from the one we know and invent some new behaviors to survive. There was a need.”
Number of people under 50 diagnosed with colorectal cancer has been increasing for 30 years
Mohammed Elamin Aliwi/Alamy
One of the most alarming trends regarding cancer is the increasing incidence of several types of tumors in people under the age of 50, especially colorectal cancer.
A £20m, five-year research project aimed at discovering the causes of the rising number of bowel cancers has been given the green light. The study will use blood, urine and stool samples from millions of people held in about 17 biobanks in Europe, North America and India.
The goal is to determine whether this increase is related to changes in food, drink, medicines, air pollutants, and other environmental chemicals by measuring everything people are exposed to (known as the “exposome”). It’s about understanding what’s going on.
“Exposomes are all the elements of the outside world that influence our health,” he says. Andrew Chan co-leader of the project at Massachusetts General Hospital in Boston;
The number of people under the age of 50 diagnosed with colorectal cancer has been increasing for 30 years. In the UK, for example, these tumors have increased by about 50 per cent in people aged 25 to 49 over this period, and similar trends are seen in the US, Canada, Australia and some European countries.
Nine out of 10 tumors occur in older people, so the increase in deaths among people under age 50 has not yet had a significant impact on the total number of cancer deaths. But this trend is worrying to doctors, especially since tumors in younger people tend to be more aggressive and diagnosed at a later stage.
Speculation abounds as to the cause, but various aspects of modern diets, including increased consumption of processed foods and red meat, and a lack of fiber, as well as antibiotic use and exposure to pollutants, are likely to be contributing factors. It is believed that this is the main cause.
In a new research projectChan and his team have attempted to identify and measure all the chemicals in medical samples obtained in previous studies, and plan to investigate further.
They will use mass spectrometry to identify the chemical signatures that disrupted the levels of novel compounds and natural biochemicals that entered the body.
One of the biobanks being used is Nurses’ Health Study 3, a large-scale project in the United States that charts the health and lifestyles of hundreds of thousands of nurses. Some participants have provided not only blood samples but also stool samples, which will allow the team to analyze gut bacteria as well.
Another important cohort is the Danish Newborn Screening Biobank. The biobank contains dried blood spots from almost every baby born in Denmark since 1982, representing approximately 2 million samples. This will allow researchers to see whether what we are exposed to in the womb is associated with an increased risk of colon cancer.
If, as expected, a correlation is found between certain biochemicals in the blood and the risk of colon cancer, the researchers will investigate whether blood tests can identify people who are more vulnerable. says Mr. Chan. “That could be a group of people who would be targeted for more intensive colon cancer testing,” he says.
Another part of the project will test whether reversing blood characteristics associated with colorectal cancer reduces people’s risk of developing the tumor. Jordana Bell Professor at King’s College London and one of Chan’s collaborators. “We seek to apply the insights we generate early by identifying putative causal factors, understanding potential mechanisms, and designing intervention trials,” she says.
Ian Fawkes from Cancer Research UK (CRUK) said: “In the United States, recent data show that people born in the 1990s have a 2.4 times higher risk of colon cancer than people born in the 1950s. Most cancer cases occur in people over age 50. “This development is an important issue for us to address. The key is to understand why the rise in early-onset cancers is occurring in the first place.”
CRUK is funding the research along with Maryland’s National Cancer Institute, France’s National Cancer Institute and the UK’s Gut Babe Foundation.
New observations of 86 planet-forming disks provide astronomers with a wealth of data and unique insight into how planets form in different regions of the Milky Way.
A planet-forming disk around a young star and its location in the gas-rich clouds of the constellation Taurus, about 600 light-years from Earth. Scientists observed a total of 43 stars in the Taurus region, all of which are pictured here (although planet-forming disks were detected in only 39 of these targets) ).Image credit: ESO / Galfi other. /Iras.
More than 5,000 exoplanets have been discovered to date, many of them in planetary systems significantly different from our solar system.
To understand where and how this diversity occurs, astronomers need to look at the dust- and gas-rich disks that envelop young stars: the cradles of planet formation. These are most commonly found in the giant gas clouds in which the stars themselves are forming.
As with mature planetary systems, new images from ESO's Very Large Telescope (VLT) show the amazing diversity of planet-forming disks.
“Some of these disks show huge spiral arms, probably driven by a complex ballet of orbiting planets,” said Christian Ginski, an astronomer at the University of Galway.
“Some show rings or large cavities formed by planet formation, while others appear smooth and almost dormant amidst this hustle and bustle of activity,” said Antonio Galfi, an astronomer at the Arcetri Astrophysical Observatory. he added.
The authors studied a total of 86 stars across three different star-forming regions in the Milky Way. Taurus and Chameleon I are both about 600 light-years from Earth, and Orion is a gas-rich cloud about 1,600 light-years from us. It is known as the birthplace of several stars more massive than the Sun.
In the Orion cloud, we found that stars in groups of two or more are less likely to have large disks that form planets.
This is an important result given that, unlike our Sun, most stars in our galaxy have companion stars.
In addition to this, the uneven appearance of the disk in this region suggests that there may be a giant planet embedded within it, which could cause the disk to become distorted or misaligned. there is.
Planet-forming disks can extend to distances hundreds of times the distance between Earth and the Sun, but because of their location hundreds of light-years from us, they appear like tiny needles in the night sky. I can see it.
To observe the protoplanetary disk, astronomers used the VLT's Spectropolarimetric High-Contrast Exoplanet Research Equipment (SPHERE).
Additional data was obtained using VLT's X-SHOOTER instrument, allowing researchers to determine how young the star is and how massive it is.
The Atacama Large Millimeter/Submillimeter Array (ALMA) has helped us understand more about the amount of dust around some stars.
Per Gunnar Vallegord, a PhD student at the University of Amsterdam, said: “The process that marks the beginning of the journey towards the formation of planets and, ultimately, the formation of life in our solar system could not be more beautiful. It's almost poetic that it is.”
Water molecules are key components in the formation of planetary systems. Astronomers using the Atacama Large Millimeter/Submillimeter Array (ALMA) have detected water vapor in the disk around the young star HL Taurus, where planets may be forming. Their analysis suggests that the hard lower limit for water vapor availability within the interior 17 astronomical units of the Taurus HL system is 3.7 Earth Oceans.
This ALMA image shows water vapor (blue tints) in the protoplanetary disk around HL Taurus. Near the center of the disk, where young stars live, the environment is hotter and the gas brighter. The red ring is a previous ALMA observation showing the distribution of dust around the star.Image credits: ALMA / ESO / National Astronomical Observatory of Japan / NRAO / Facchini other.
Water molecules are undoubtedly one of the most important molecular species in the entire universe.
Water is a highly efficient solvent, so it played a key role in the emergence of life as we know it on Earth.
For this reason, chemical characterization of exoplanetary atmospheres often focuses on detecting this specific molecule.
Water, formed from common hydrogen and oxygen atoms, is so abundant in both gas and ice form that it plays a fundamental role in the physics of planetary system formation.
Dr Stefano Facchini, an astronomer at the University of Milan, said: “We never imagined that we would be able to image oceans of water vapor in areas where planets are likely to form.”
The HL Taurus system is believed to be less than 100,000 years old and has a radius of about 17.9 billion km. It is located 450 light years away in the direction of the constellation Taurus.
The protoplanetary disk of HL Taurus is unusually large and bright, making it a perfect place to look for signs of planet formation.
New ALMA observations reveal that there is at least three times more water inside the disk than in Earth's entire ocean.
Dr Leonardo Testi, an astronomer at the University of Bologna, said: “It is truly amazing that we can not only detect water vapor 450 light-years from us, but also obtain detailed images and spatially resolve it.” said.
Spatially resolved observations with ALMA allow astronomers to determine the distribution of water in different regions of the disk.
“Participating in such an important discovery of the iconic HL Taurus disk was beyond my expectations given my first research experience in astronomy,'' said Dr. Mathieu Vander Donk, an astronomer at the University of Liege. he said.
Dr Facchini said: “Our recent images reveal that significant amounts of water vapor are present at distances from the star that include gaps where planets may now be forming.” said.
“This suggests that this water vapor could influence the chemical composition of planets that form in those regions.”
“To date, ALMA is the only facility capable of spatially resolving water in cold planet-forming disks,” said Professor Wouter Bremings, an astronomer at Chalmers University of Technology.
ESO astronomer Dr Elizabeth Humphreys said: “It's really exciting to be able to witness first-hand in photographs the ejection of water molecules from icy dust particles.”
“The dust particles that make up the disk are the seeds for planet formation, colliding and clumping together to form even larger bodies orbiting the star.”
“Our findings show how the presence of water influences the development of planetary systems, similar to our own solar system about 4.5 billion years ago,” Dr. Facchini said.
of findings It was published in the magazine natural astronomy.
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S. Facchini other. HL Resolved ALMA observations of water in the inner astronomical unit of the Tau disk. Nat Astron, published online on February 29, 2024. doi: 10.1038/s41550-024-02207-w
The members of the WhatsApp group ‘Smartphone Free Childhood’ advocate for banning under-14s from owning smartphones and preventing under-16s from accessing social media to protect them from the dangers of the internet. However, believing this is the solution is unrealistic. Announcement (“Crazy: Thousands of UK parents join in quest for smartphone-free childhood”, February 17).
It is a parent’s responsibility to provide a safe environment for their children and teach them how to safely navigate the internet. Just like roads can be dangerous but we don’t ban cars, teaching children internet safety is crucial. Building open and honest relationships and setting boundaries at home will help young people understand internet dangers better than blanket bans. Making social media “adults only” may backfire and make it more tempting for children. They may also be less likely to seek help if they encounter inappropriate content. stuart harrington Burnham-on-Sea, Somerset
As seen in cases like Brianna Gee’s, giving children smartphones can have negative consequences. However, we should consider the benefits and drawbacks of smartphone access. I personally benefitted from having a smartphone in school for various tasks like using apps for transportation, news, and communication. While parental controls and monitoring are essential, smartphones have many positive uses. It is important to adapt to the changing online threats and promote more parental supervision. oscar acton Merton, County Durham
Sagittarius C is located just 300 light-years from Sagittarius A*, the supermassive black hole at the center of the Milky Way.
This image of the Sagittarius C region from ESO's Very Large Telescope includes hundreds of thousands of stars. Image credit: ESO/F. Nogueras-Lara.
The center of the Milky Way is the most prolific star-forming region in the entire galaxy.
But astronomers have discovered only a fraction of the young stars they had expected. There is “fossil” evidence that many more stars than we actually see were born recently.
This is because heading to the center of the Milky Way is not an easy task. Clouds of dust and gas block the light from the star, obscuring visibility.
“On average by volume, the galactic center stands out as the most prolific star-forming environment in the galaxy,” said ESO astronomer Francisco Nogueras Lara.
“Over the past 30 million years, we have witnessed the formation of about 1 million stars.”
“But crowding and high extinction rates have hampered their discovery, and so far only a fraction of the young star's expected mass has been confirmed.”
By studying the stellar population of Sagittarius C, Dr. Lara aimed to detect young stars hidden in the galactic center.
He found that Sagittarius C is much richer in young stars than other regions of the galactic center.
“We found that Sagittarius C contains the solar mass of hundreds of thousands of young stars,” Dr. Lara said.
“We compared our results to a recently discovered population of young stars in Sagittarius B1, located at the opposite end of the nuclear star disk.”
“The young stars in Sagittarius C are estimated to be about 20 million years old and likely represent the next evolutionary step for the slightly younger stars in Sagittarius B1.”
“Our discovery contributes to addressing the discrepancy between the expected number of young stars at the center of galaxies and the number of detected stars, and sheds light on their evolution in this extreme environment.”
“As a secondary result, we discovered that Sagittarius C has a population of intermediate-aged stars (approximately 50% of the mass of stars between 2 billion and 7 billion years old), which is composed of a nuclear stellar disk. It does not exist in the innermost region of the world (which is dominated by stars older than 7 billion years).
“This confirms the existence of an age gradient, driving the formation of an inside-out nuclear star disk.”
of findings appear in the diary astronomy and astrophysics.
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F. Nogueras-Lara other. 2024. Hunt young stars at the center of the galaxy. Solar masses of hundreds of thousands of young stars in the Sagittarius C region. A&A 681, L21; doi: 10.1051/0004-6361/202348712
NASA’s Stardust mission returned rocky material from the coma of comet 81P/Wild 2 (pronounced “Wild-2”) to Earth on January 15, 2006. Comet Wild 2 contains volatile ice, which may have accreted beyond Neptune’s orbit. The Wild 2 sample was expected to be rich in primordial molecular cloud material, i.e., interstellar and circumstellar particles. Instead, it turns out that Wild 2’s interstellar component is very small, and nearly all of the returned particles formed in a wide and diverse region of the solar nebula. Although some features of the Wild 2 material resemble primitive chondrite meteorites, the diversity of its composition attests to a very different origin and evolutionary history from asteroids. Wild 2 has very little impact debris from asteroids, and may have accreted dust from the outer and inner Solar System before the solar nebula dispersed.
Comet 81P/Wild 2. Image courtesy of NASA.
wild 2 is a small comet in the shape of a flat sphere, approximately 1.65 x 2 x 2.75 km (1.03 x 1.24 x 1.71 miles).
Discovered by Paul Wilde on January 6, 1978, this comet has an orbital period of 6.2 years.
Wild 2 is known as a fresh periodic comet. It orbits the Sun between Mars and Jupiter, but it did not always follow this orbit.
Originally, this comet’s orbit was between the orbits of Uranus and Jupiter. On September 9, 1974, a gravitational interaction between Wild 2 and Jupiter changed its orbital period from her 43 years to her 6.2 years.
“Eighteen years after NASA’s Stardust mission returned the first known sample from a comet to Earth, the true nature of the icy object is coming into focus,” says the new study. said author Ryan Oriol, a researcher at Washington University in St. Louis.
“When Stardust launched in 1999, many scientists predicted that the comet’s rocky material would be dominated by the primordial dust that built our solar system, the ‘stardust’ from which the mission takes its name. I was there.”
“But the actual samples told a different story: Wild 2 contained a potpourri of dust formed from various early events in the solar system’s history.”
For Dr. Oriole, the discovery that Wild 2 contained records of “local” events was exciting.
“This comet was a witness to the events that shaped the solar system into what we see today,” he said.
“Because the comet was kept in a cold storage in space for almost its entire life, it avoided the heat and water alterations seen in asteroid samples.”
“Comet Wild 2 contains things never seen before in a meteorite, including rare carbon and iron assemblages and precursors to the igneous globules that make up the most common type of meteorite. . And all of these objects are beautifully preserved within Wild 2.”
“Almost 20 years later, scientists have had enough time to analyze the tiny amounts of material returned from the Stardust mission, less than a milligram (think a grain of sand). You might see it.”
“But this material is dispersed into thousands of tiny particles on a collector the size of a pizza.”
“Almost every Wild 2 particle is unique and has a different story to tell. Extracting and analyzing these grains is a time-consuming process. But the scientific benefits are huge. .”
“Most of the Wild 2 particles have not yet been studied and certainly hold many more surprises. Over time, we will be able to study the samples using new techniques that did not exist at the start of the mission.” Masu.”
“Stardust samples, microscopic particles taken from celestial bodies less than two miles wide, contain a deep record of the past that spans billions of miles. After 18 years of studying this comet, we have We now have a better understanding of the dynamic formative period.”
study Published in Journal November 2023 issue geochemistry.
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Ryan C. Oriol. 2023. Comet 81P/Wild 2: A record of the solar system’s wild youth. geochemistry 83 (4): 126046; doi: 10.1016/j.chemer.2023.126046
According to some researchers, the oldest of these stars is 1.5 billion years old, while the youngest is only 100 million years old. paper Published in Astrophysics Journal Letter.
This infrared image from Hubble shows the Milky Way Core Cluster, the densest and most massive star cluster in our galaxy. Image credit: NASA / ESA / Hubble Heritage Team / STScI / AURA / T. Do & A. Ghez, UCLA / V. Bajaj, STScI.
The center of our Milky Way galaxy is located about 27,000 light-years away in the constellation Sagittarius and is a crowded place.
This region is so dense that it’s equivalent to a million stars crammed into the space between the Sun and Alpha Centauri, 4.3 light-years away.
This nuclear cluster surrounds Sagittarius A*, a 4.3 million solar mass black hole at the center of the galaxy.
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In general, many nuclear star clusters coexist with supermassive black holes, which are found in more than 70% of galaxies with masses greater than 100 million to 10 billion solar masses.
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“In previous work, we hypothesized that these particular stars in the middle of the Milky Way may be unusually young,” said Lund University astronomer Rebecca Forsberg.
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“Now we can confirm this. Our study shows that three of these stars are relatively young, at least as far as astronomers are concerned, ranging in age from 100 million years to about 1 billion years. We were able to determine the age.”
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“This is equivalent to the age of the Sun, which is 4.6 billion years old.”
This panorama shows the central region of the Milky Way galaxy. It builds on previous surveys by NASA’s Chandra X-ray Observatory and other telescopes, and extends Chandra’s high-energy field of view further up and down the galactic plane than previous imaging campaigns. The X-rays from Chandra are orange, green, and violet, indicating different X-ray energies. Radio data from MeerKAT is gray. Image credits: NASA / CXC / UMass / QD Wang / NRF / SARAO / MeerKAT.
In this study, Dr. Forsberg and colleagues used high-resolution data from the Keck II telescope in Hawaii. This Keck II telescope is one of the largest telescopes in the world with a 10 meter diameter mirror.
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For further verification, they measured the amount of iron, a heavy element, in the stars
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This element is important in tracking the development of galaxies. This is because astronomers’ theories about star formation and galaxy development show that the formation of heavy elements increases over time in the Universe, so younger stars contain more heavy elements.
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To determine iron levels, astronomers looked at the star’s spectrum in infrared light. Infrared light is a part of the light spectrum that can more easily illuminate dust-dense parts of the Milky Way compared to optical light.
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Researchers say there is considerable variation in iron levels.
“The very wide spread in iron levels could indicate that the innermost parts of the galaxy are incredibly heterogeneous, or unmixed,” said Dr. Brian Thorsbro, an astronomer at Lund University. Stated.
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“This is something we didn’t expect, and it tells us something not only about what the center of a galaxy looks like, but also about what the early universe looked like.”
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“Personally, I think it’s very exciting that we can now study the galactic center itself at such a detailed level,” Dr. Forsberg said.
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“While these types of measurements have been standard for observations of our own galactic disk, they have been an unattainable goal in more remote and exotic parts of the galaxy.”
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“Studies like this can teach us a lot about how our home galaxy formed and developed.”
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B. Thorsbro other. 2023. The range of old metallicities of stars in nuclear clusters is wide. APJL 958, L18; doi: 10.3847/2041-8213/ad08b1
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