#galaxy_classification

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The Hubble telescope captured the galaxy NGC 685, made up of more than 100 million stars, appearing to orbit in the depths of space The average galaxy NGC 685 contains at least 100 million stars. About 58 million light-years from Earth, galaxy NGC 685 appears to be orbiting in the depths of space. The Hubble Space Telescope image, the last of six released as part of Hubble's Galaxy Week, shows the galaxy with its spiral arms dotted with countless pockets of bright blue regions called star clusters. Closer to the center of the galaxy, there are also many twisted red wisps, representing bands of gas and dust where new generations of stars form over eons. [caption id="attachment_69171" align="aligncenter" width="598"] galaxy[/caption] NGC 685: a galaxy home to millions of stars surprised Hubble NASA's accompanying description of the photo of the galaxy NGC 685 says it is located in the constellation Eridanus, measures about 60,000 light-years, and may contain at least 100 million stars. In comparison, the Milky Way is estimated to consist of approximately 100 billion stars. Despite the difference in size and number of stars, both galaxies have an interesting feature: they have a central bar that crosses the cores of the galaxies. In this image of the galaxy NGC 685, this red-flecked bar can be seen stretching horizontally within a small circle of gas and dust. Its intense brilliance is due to the many stars concentrated in a relatively small area. Previous studies have shown that such bars are observed in about two-thirds of spiral galaxies. Gas and other material flows into the galactic cores through these bridges, indicating that the galaxy's "formative period" is over, astronomers say. Although little time has been devoted to studying NGC 685, studying bar galaxies like this one helps astronomers understand how galaxies evolve and whether the process is different for our galaxy.

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Research shows that some Milky Way star clusters did not form within the galaxy, but appear to have been "stolen" from other galaxies According to recent research in astronomy, most large galaxies arose from the merger of small galaxies. This means that some star clusters currently in the Milky Way may have been inherited from absorbed galaxies, or even "stolen" from neighboring galaxies such as the Magellanic Clouds. The first connections between these clusters and different host galaxies were discovered in the 1990s, but recent research has become increasingly informative, allowing the percentage of clusters stolen and which clusters were "stolen" to be determined. The Milky Way is adjacent to a large number of galaxies. This includes the famous Magellanic Clouds, as well as lesser-known ones such as the Fornax Dwarf Galaxy and the Antlia 2 Dwarf Galaxy. The discovery of streams of ruptured clusters driven by tidal forces has offered a possible explanation for why many star clusters in the Milky Way are similar in age while others are relatively young. Astronomers have suggested that these young clusters formed inside dwarf galaxies. [caption id="attachment_68895" align="aligncenter" width="768"] Milky Way[/caption] Over time, more and more evidence has been collected to support this argument. In 2002, the cluster NGC 5634 was discovered to be in a stream emanating from a dwarf galaxy in the constellation Sagittarius. Its motion and poor metal content also pointed to an origin in a dwarf galaxy. Since then, astronomers have found compelling evidence that several other star clusters are associated with this stream-torn galaxy. Among them: AM 4, Arp 2, Pal 12, NGC 2419, NGC 4147, Terzan 7, Terzan 8, Whiting 1. Meanwhile, other streams of broken dwarf galaxies have been discovered, including the Helm Stream, the Gaia-Enceladus Stream, and the Sequoia Galaxy. More associations with additional star clusters followed. In addition to the galaxies currently undergoing engulfment, astronomers have also suggested that some more intact dwarf galaxies orbiting the Milky Way could have contributed. how did star clusters from other galaxies end up in the Milky Way? In a recent series of papers, astronomers from the Iran University of Science and Technology have studied how various neighboring galaxies of the Milky Way can exchange clusters. In their first work, they built models of dwarf galaxies with star clusters in different orbits around the Milky Way to study how easily their clusters could separate from their host galaxy. They found that the percentage of such clusters varied from 12% to 93%. Clusters were most often "stolen" if they had elliptical orbits that reached the outskirts of their parent galaxies. However, more massive galaxies were better able to hold together their clusters. Based on this range, the paper suggested that at least two clusters could have been stolen from the Fornax galaxy, four from the Large Magellanic Clouds, two from the Small Magellanic Clouds, and fourteen from the Sagittarius dwarf galaxy. In the second paper, the researchers took a different approach and studied the orbital characteristics of 154 globular star clusters and compared them with the characteristics of 41 dwarf galaxies around the Milky Way and other tidally disrupted systems. They identified 14 clusters associated with the Sagittarius dwarf galaxy. However, their results disagree with other studies regarding exactly what kind of clusters these are. Five clusters previously associated with the Sagittarius dwarf galaxy, according to the authors, did not have sufficiently similar parameters to be considered “stolen.” However, they identified four new globular clusters not previously associated with the galaxy as having a high probability of originating in another galaxy, and six others with a lower probability. The study also found six clusters that likely formed in the Large Magellanic Cloud. As a result, their review notes that 29 of the known star clusters have properties similar enough to the dwarf galaxies considered to trace their connection. The authors acknowledge that their models are somewhat oversimplified because they do not fully account for the three-dimensional structure of dwarf galaxies. Thus, they leave it open for future research, which will include further study of the newly identified star clusters. These studies provide more evidence that the Milky Way's star clusters are not its population. They are a combination of clusters from other galaxies and clusters formed within satellite galaxies.

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The unexpected discovery has given rise to new theories about the mechanism by which phosphorus is formed without the outbursts of massive stars. The origin of life from “organic soup” is a complex process. This requires many different components assembled in one place and under the right conditions. Although the exact conditions are still a matter of debate, scientists have an idea of ​​what elements of the periodic table are needed. One important component is phosphorus, which was recently discovered on the outskirts of the Milky Way. The presence of this element among others is considered necessary for the formation of basic biochemical molecules. Therefore, the presence of phosphorus determines the boundaries of habitable zones in galaxies. Phosphorus is typically produced by the death of massive stars, making its presence at the outskirts of a galaxy a rare occurrence. However, the recent discovery of phosphorus in this area suggests that other mechanisms for its formation may exist. [caption id="attachment_85298" align="aligncenter" width="780"] Milky Way galaxy[/caption] “Phosphorus is an element that requires a special, catastrophic event to form. According to popular belief, phosphorus is formed as a result of supernova explosions of stars with a mass of at least 20 solar masses. They are the source of strong energetic emissions and a series of nucleosynthesis reactions that form not only phosphorus, but also many other heavy elements,” says astronomer and chemist Lucy Ziouris, who works at Arizona State University and Steward Observatory. This is the generally accepted view, and the discovery of phosphorus far from massive stars or supernova remnants suggests that there are other ways this element can be formed. All the elements we see around us are formed in stars. After the formation of the first atoms of the Universe from the primordial plasma, the atoms were mainly composed of hydrogen and helium, and all other elements appeared after the birth of the first stars. Stars play an important role in the fusion and combination of atoms in their cores, resulting in the formation of heavier elements. On the outskirts of the Milky Way galaxy The formation of elements in a star depends on its mass. Stars are the size of our Sun and are smaller able to support reactions that create light elements such as lithium and beryllium when hydrogen and helium combine. More massive stars can produce heavier elements such as oxygen and nitrogen. However, phosphorus is not produced during such reactions inside the star. Supernova explosions, accompanied by the death of massive stars, are one of the known mechanisms for the origin of phosphorus. Flares eject elements into space, scattering astromaterials into the interstellar medium, where they can be absorbed by new generations of stars, as well as comets and planets. Massive stars can only form in regions where there is enough material to feed them. As you move away from the center of the galaxy, the density of matter decreases - the outskirts of galaxies are usually populated by massive stars. So the presence of phosphorus in a cloud called WB89-621, located about 74,000 light-years from the center of the Milky Way, poses a mystery to astrochemists. “The discovery of phosphorus at the edge of the galaxy raises questions and adds an additional piece to our puzzle. The presence of phosphorus in this area suggests that the process of its formation is more complex and is not limited only to supernova explosions,” explains chemist Liliya Koelemey, collaborating with Arizona State University. There are two main explanations for this phenomenon. One of them is associated with the “galactic fountain” model, which assumes the movement of elements from the inner regions of the galaxy to the outer through supernova explosions, ejecting matter from the galactic disk into the halo and its subsequent cooling and return. However, this explanation is questionable, since observational data on galactic fountains is not yet sufficient. Another explanation involves the possibility of phosphorus being formed in the region around the core of less massive stars by capturing neutrons. Here, silicon isotopes can capture additional neutrons to form phosphorus. The discovery of phosphorus on the outskirts of the Milky Way is an exciting and important study, valuable for understanding the formation of life in the Universe. This element is the last of the NCHOPS - nitrogen, carbon, hydrogen, oxygen, phosphorus and sulfur - essential building blocks for the emergence of life and which define the habitable zones of a galaxy. Previously, astronomers had not paid much attention to the outskirts of galaxies in search of exoplanets with biomarkers, because they believed that regions far from the center of galaxies did not have enough phosphorus. However, this discovery allows us to expand the scope of searches.

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The unexpected discovery has given rise to new theories about the mechanism by which phosphorus is formed without the outbursts of massive stars. The origin of life from “organic soup” is a complex process. This requires many different components assembled in one place and under the right conditions. Although the exact conditions are still a matter of debate, scientists have an idea of ​​what elements of the periodic table are needed. One important component is phosphorus, which was recently discovered on the outskirts of the Milky Way. The presence of this element among others is considered necessary for the formation of basic biochemical molecules. Therefore, the presence of phosphorus determines the boundaries of habitable zones in galaxies. Phosphorus is typically produced by the death of massive stars, making its presence at the outskirts of a galaxy a rare occurrence. However, the recent discovery of phosphorus in this area suggests that other mechanisms for its formation may exist. [caption id="attachment_85298" align="aligncenter" width="780"] Milky Way galaxy[/caption] “Phosphorus is an element that requires a special, catastrophic event to form. According to popular belief, phosphorus is formed as a result of supernova explosions of stars with a mass of at least 20 solar masses. They are the source of strong energetic emissions and a series of nucleosynthesis reactions that form not only phosphorus, but also many other heavy elements,” says astronomer and chemist Lucy Ziouris, who works at Arizona State University and Steward Observatory. This is the generally accepted view, and the discovery of phosphorus far from massive stars or supernova remnants suggests that there are other ways this element can be formed. All the elements we see around us are formed in stars. After the formation of the first atoms of the Universe from the primordial plasma, the atoms were mainly composed of hydrogen and helium, and all other elements appeared after the birth of the first stars. Stars play an important role in the fusion and combination of atoms in their cores, resulting in the formation of heavier elements. On the outskirts of the Milky Way galaxy The formation of elements in a star depends on its mass. Stars are the size of our Sun and are smaller able to support reactions that create light elements such as lithium and beryllium when hydrogen and helium combine. More massive stars can produce heavier elements such as oxygen and nitrogen. However, phosphorus is not produced during such reactions inside the star. Supernova explosions, accompanied by the death of massive stars, are one of the known mechanisms for the origin of phosphorus. Flares eject elements into space, scattering astromaterials into the interstellar medium, where they can be absorbed by new generations of stars, as well as comets and planets. Massive stars can only form in regions where there is enough material to feed them. As you move away from the center of the galaxy, the density of matter decreases - the outskirts of galaxies are usually populated by massive stars. So the presence of phosphorus in a cloud called WB89-621, located about 74,000 light-years from the center of the Milky Way, poses a mystery to astrochemists. “The discovery of phosphorus at the edge of the galaxy raises questions and adds an additional piece to our puzzle. The presence of phosphorus in this area suggests that the process of its formation is more complex and is not limited only to supernova explosions,” explains chemist Liliya Koelemey, collaborating with Arizona State University. There are two main explanations for this phenomenon. One of them is associated with the “galactic fountain” model, which assumes the movement of elements from the inner regions of the galaxy to the outer through supernova explosions, ejecting matter from the galactic disk into the halo and its subsequent cooling and return. However, this explanation is questionable, since observational data on galactic fountains is not yet sufficient. Another explanation involves the possibility of phosphorus being formed in the region around the core of less massive stars by capturing neutrons. Here, silicon isotopes can capture additional neutrons to form phosphorus. The discovery of phosphorus on the outskirts of the Milky Way is an exciting and important study, valuable for understanding the formation of life in the Universe. This element is the last of the NCHOPS - nitrogen, carbon, hydrogen, oxygen, phosphorus and sulfur - essential building blocks for the emergence of life and which define the habitable zones of a galaxy. Previously, astronomers had not paid much attention to the outskirts of galaxies in search of exoplanets with biomarkers, because they believed that regions far from the center of galaxies did not have enough phosphorus. However, this discovery allows us to expand the scope of searches.

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In 2024, comet 12P/Pons-Brooks with strange “horns” will approach Earth. It will become bright and visible to the naked eye during a solar eclipse. Observations will help establish a connection between comets and solar radiation Comet 12P/Pons-Brooks was first discovered by Jean-Louis Pons in 1812. It was subsequently spotted by William Robert Brooks in 1883 as 12P returned for another round of its 71-year orbit. Since then, 12P has only returned once, in 1954, and will stop by again in April 2024. Comet 12P has a diameter of about 30 kilometers, its core is made of ice, dust, and gas, which interact with solar radiation to varying degrees, depending on how close it is to the Sun. As it approaches perihelion (the closest point in its orbit to the Sun), sunlight heats the comet's nucleus, creating pressure that must be released.  The eruption releases gas and dust from the ice into space, creating a bright coma that astronomers can easily observe from afar. On October 5, astronomers witnessed a massive eruption. The gas and dust coming out of the comet reflected more light, making it tens of times brighter than usual.  [caption id="attachment_72778" align="aligncenter" width="780"] galaxy[/caption] Comet with horns 12P flies towards Earth: in 2024, the sky expects a phenomenon from a distant galaxy Over the next few days, astronomers watched as two large horns grew from the back of 12P. The result is an object that looks a bit like the Millennium Falcon, the Star Wars ship piloted by Han Solo and Chewbacca (12P is a reference to 12 Parsecs*).  Astronomers believe that the "horns" arose due to the unusual shape of the comet, which blocks the exit of gas and dust, dividing them into two streams. The horns have probably dissipated now, but they may grow back as the comet approaches perihelion. The closer it gets to the Sun, the more exposure it will have to endure from the Sun, and the likelihood of developing growths will increase as it gets closer. In addition, astronomers speculate that the eruptions of gas and dust further create uneven brightness when observing the comet, making the horns more visible.  In June 2024, Comet 12P will be about 232 million kilometers away and bright enough to be seen with the naked eye under clear, dark skies. And making for even better viewing conditions, perihelion falls around the same period as the 2024 total solar eclipse, allowing observers to see two phenomena simultaneously. *Han Solo claimed that his Millennium Falcon "traversed the Kessel Arc in less than 12 parsecs."

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Astronomers have discovered a galaxy that already had a high concentration of metals a billion years after the Big Bang. Early galaxies contain mostly hydrogen and helium, but this distant galaxy is anomalously rich in metals The universe is becoming more metallic over time: in its younger days, it was composed mostly of hydrogen and helium. But recently, researchers discovered a galaxy that was well ahead of this trend and, a billion years after the Big Bang, had accumulated a high content of metals. Almost all atoms heavier than helium originate in stars, the “forges of the cosmos,” which transform primordial materials into the many different elements we see today. These "forges" process the finite amount of hydrogen and helium in the Universe. As a result, the total supply of hydrogen decreases over time, while the proportion of heavier elements (which astronomers call "metals" regardless of their actual metallic properties) increases. When astronomers look back and observe the early stages of the universe, they expect to see mostly pure hydrogen and helium. [caption id="attachment_68900" align="aligncenter" width="780"] galaxy[/caption] This prediction is generally supported by observations, and when looking at galaxies created in the first 1.5 billion years after the Big Bang, researchers most often observe clouds of gas that contain almost no metals. However, a collaboration led by Jianhao Huyang of the University of South Carolina recently discovered a contradiction to this convention: their observations of a hazy galaxy created a billion years ago showed a metal fraction higher than predicted for such a young source by more than two orders of magnitude. Astronomers have discovered a galaxy that set the trend for a high proportion of metals before anyone else Huyang and his colleagues made this discovery by observing a distant quasar called SDSS J002526.84-014532.5, which has a redshift of 5.07. Between the Earth and this source, there is a galaxy with a redshift of 4.74. As light from a quasar passes through the diffuse gas of a galaxy on its way to our telescopes, certain wavelengths of radiation are preferentially absorbed by the molecules and atoms they encounter along the way. By measuring the relative amount of this absorption, the researchers were able to determine which elements were trying to block the path of light and how dense they were. They discovered that the galaxy contains significant amounts of carbon, oxygen, magnesium, and other heavy elements. Just 1.2 billion years after the Big Bang, this galaxy already had a greater relative amount of carbon and oxygen than our own Sun, which was born many billions of years later. Models of early galaxy formation predict a significantly lower proportion of metals, even taking into account the large uncertainties of described but not yet seen first-generation stars. Like many unexpected discoveries, the authors of the present study cannot yet explain what could lead to such a significant content of heavy elements. They acknowledge that this may be because looking at this particular direction may have passed through a patch of "developed" gas, and the galaxy as a whole may be as metal-poor as expected. However, in this case, they will not be able to explain how the light passed through such a small area with exactly the composition data obtained. It may be time to reconsider models of the chemical evolution of early galaxies, or there may be something special about this particular galaxy that remains hidden.

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Galactic archeology reveals the dramatic history of Andromeda. The formation of the galaxy was more intense than that of the Milky Way, with several periods of intense star formation caused by galactic collisions A study led by scientists from the University of Hertfordshire has revealed the dramatic history of Andromeda, our closest neighboring galaxy. An international team of astrophysicists has determined details of the galaxy's history through galactic archaeology, an approach that studies the chemical composition of stars and the development of their host galaxy to reconstruct its past. Scientists examined the elemental composition of Andromeda, and the gas and dust content of planetary nebulae formed from the discarded outer layers of dying low-mass stars. [caption id="attachment_68817" align="aligncenter" width="780"] Milky Way[/caption] The analysis showed that the formation of Andromeda was more dramatic and powerful than the formation of our Galaxy. After the intense burst of star formation at the time of the galaxy's creation between 2 and 4.5 billion years ago, another burst occurred, most likely caused by the so-called "wet merger" - the merger of two gas-rich galaxies that provokes intense star formation. Andromeda's history turns out to be more dramatic than that of the Milky Way Scientists, based on the position and movement of individual stars within the galaxy, have long assumed that Andromeda was formed by the merger of two galaxies. Professor Kobayashi's research sheds light on the nature and consequences of such a merger using the chemical composition of stars and explains how stars and elements formed throughout Andromeda's history. [caption id="attachment_68818" align="aligncenter" width="780"] Milky Way[/caption] Professor of Astrophysics Kobayashi, from the Center for Astrophysics Research at the University of Hertfordshire, said: “This is a fantastic example of how galactic archeology can provide new insights into the history of the universe. By analyzing the chemical enrichment of different generations of stars in Andromeda, we can bring its history to life and better understand its origins." Professor Kobayashi's theoretical model predicts two different compositions of stars in the two components of Andromeda's disk. One composition contains ten times more oxygen than iron, and the other contains approximately equal amounts of oxygen and iron. These simulations are supported by spectroscopic observations of planetary nebulae and observations of red giants by the James Webb Space Telescope (JWST). The new study continues Professor Kobayashi's work on the origin of elements in the Universe. As he explains: “Oxygen is one of the so-called alpha elements created by massive stars. Other alpha elements include neon, magnesium, silicon, sulfur, argon, and calcium. Oxygen and argon have been measured using observations of planetary nebulae, but Andromeda is so distant that measuring other elements, including iron, will require JWST." In the coming years, JWST and large ground-based telescopes will continue to observe Andromeda, confirming new results.