Astronomers Identified the Nature of Instability in the Accretion Disk of the Galaxy NGC 4258

The galaxy NGC 4258 is 22.8 million light-years from Earth.
Photo Credit: NASA

An international group of researchers, including Andrey Sobolev, a leading researcher at the Kourovka Astronomical Observatory of the Ural Federal University, for the first time examined the details of the distribution of maser emissions in the accretion It was found that in this disk acts magneto-rotational instability. Scientists reported the discovery in the journal Nature Astronomy.

"The discovery of a disk around this galaxy was reported by Miyoshi and Greenhill back in 1995 in articles in Nature and in The Astrophysical Journal. That was the first time we knew there was a disk. But now, with the RadioAstron's ultra-high angular resolution, we have been able to ascertain for the first time the details of the distribution of the maser emission spots. The regularity in their maser locations is explained by the fact that there is a magneto-rotational instability in the accretion disk," says Andrey Sobolev.

The instabilities determine the evolution of disks. We can use them to know whether the disk is stationary or whether everything in it is changing rather rapidly. In other words, the instabilities help determine the physical status or physical state of the disk: how it is formed, what happens in it, and predict whether it will change over time. Therefore, to understand the processes that occur in the accretion disk, scientists need to understand what instabilities are operating there, and the detection of the magneto-rotational instability is extremely important. At the same time, scientists are not going to put an end to the research of the unique object around the supermassive black hole. According to Sobolev, now it is the turn of theorists to explain the unique data obtained at the cosmic interferometer - the largest device created by mankind. This interferometer was created as part of the RadioAstron project, in which Russian scientists play a leading role.

Long-term liquid water also on non-Earth-like planets?

Low-mass planets with a primordial atmosphere of hydrogen and helium might have the temperatures and pressures that allow water in the liquid phase. The presence of liquid water is favorable for life, so that these planets potentially harbor exotic habitats for billions of years.
Credit: (CC BY-NC-SA 4.0) - Thibaut Roger - Universität Bern - Universität Zürich

Liquid water is an important prerequisite for life to develop on a planet. As researchers from the University of Bern, the University of Zurich and the National Centre of Competence in Research (NCCR) PlanetS report in a new study, liquid water could also exist for billions of years on planets that are very different from Earth. This calls our currently Earth-centered idea of potentially habitable planets into question.

Life on Earth began in the oceans. In the search for life on other planets, the potential for liquid water is therefore a key ingredient. To find it, scientists have traditionally looked for planets similar to our own. Yet, long-term liquid water does not necessarily have to occur under similar circumstances as on Earth. Researchers of the University of Bern and the University of Zurich, who are members of the National Centre of Competence in Research (NCCR) PlanetS, report in a study published in the journal Nature Astronomy, that favorable conditions might even occur for billions of years on planets that barely resemble our home planet at all.

NASA's Chandra Catches Pulsar in X-ray Speed Trap

G292.0+1.8: NASA's Chandra Catches Pulsar in X-ray Speed Trap
Credit: X-ray: NASA/CXC/SAO/L. Xi et al.; Optical: Palomar DSS2
Hi-Res Zoomable Image

A young pulsar is blazing through the Milky Way at a speed of over a million miles per hour. This stellar speedster, witnessed by NASA's Chandra X-ray Observatory, is one of the fastest objects of its kind ever seen. This result teaches astronomers more about how some of the bigger stars end their lives.

Pulsars are rapidly spinning neutron stars that are formed when some massive stars run out of fuel, collapse, and explode. This pulsar is racing through the remains of the supernova explosion that created it, called G292.0+1.8, located about 20,000 light-years from Earth.

"We directly saw motion of the pulsar in X-rays, something we could only do with Chandra's very sharp vision," said Xi Long of the Center for Astrophysics | Harvard & Smithsonian (CfA), who led the study. "Because it is so distant, we had to measure the equivalent of the width of a quarter about 15 miles away to see this motion."

To make this discovery, the researchers compared Chandra images of G292.0+1.8 taken in 2006 and 2016. From the change in position of the pulsar over the 10-year span, they calculated it is moving at least 1.4 million miles per hour from the center of the supernova remnant to the lower left. This speed is about 30% higher than a previous estimate of the pulsar's speed that was based on an indirect method, by measuring how far the pulsar is from the center of the explosion.

Wandering star disrupts stellar nursery

A young protostar in L483 and its signature outflow peeks out through a shroud of dust in this infrared image from NASA's Spitzer Space Telescope. Stars are known to form from collapsing clumps of gas and dust, or envelopes, seen here around a forming star system as a dark blob, or shadow, against a dusty background. The greenish color shows jets coming away from the young star within. The envelope is roughly 100 times the size of our solar system.
Credit: NASA/JPL-Caltech/J.Tobin University of Michigan

From a zoomed out, distant view, star-forming cloud L483 appears normal. But when a Northwestern University-led team of astrophysicists zoomed in closer and closer, things became weirder and weirder.

As the researchers peered closer into the cloud, they noticed that its magnetic field was curiously twisted. And then — as they examined a newborn star within the cloud — they spotted a hidden star, tucked behind it.

“It’s the star’s sibling, basically,” said Northwestern’s Erin Cox, who led the new study. “We think these stars formed far apart, and one moved closer to the other to form a binary. When the star traveled closer to its sibling, it shifted the dynamics of the cloud to twist its magnetic field.”

The new findings provide insight into binary star formation and how magnetic fields influence the earliest stages of developing stars.

Cox presented this research at the 240th meeting of the American Astronomical Society (AAS) in Pasadena, California. “The Twisted Magnetic Field of L483” will take place on Tuesday, June 14, as a part of a session on “Magnetic Fields and Galaxies.” The Astrophysical Journal will also publish the study next week.

Speed and dense gas bend jets of matter streaming away from some galaxy centers

Paired jets of matter streaming away from supermassive black holes at the center of galaxies usually extend away in opposite directions along the black hole’s axis of spin — as in the two bottom galaxy images. But some, like the two top galaxies, have jets bent at odd angles.
Credit: Melissa Morris, Uw–Madison

The most active and gluttonous black holes in the universe can often be found with two jets of matter streaming from their centers. These jets accelerate with astounding speed out into space in opposite directions, and they are usually lined up along the axis of the spinning black hole. But not always.

Some of these supermassive black galaxy hearts, called active galactic nuclei, have jets bent at mysteriously odd angles. New research from astronomers at the University of Wisconsin–Madison, published recently in The Astronomical Journal, shows that these jets are probably bent by a combination of their galaxies moving at tremendous velocity and by drag on the jets as they pass through clouds of intergalactic gas.

“These active galactic nuclei are a subset of black holes that are — even for black holes — really quickly gobbling up an enormous amount of matter,” says Melissa Morris, a UW–Madison astronomy graduate student and lead author of the new study. “They’re being fueled so quickly that a ton of energy is released in the area around the black hole. That’s what causes these wild AGN jets.”

Researchers find ten-billion-year-old “ghost stars” from swallowed galaxy

Two galaxies merging 
Illustration: International Gemini Observatory/NOIRLab/NSF/AURA/J. da Silva

Astronomers at Lund University in Sweden have found a group of stars in the Milky Way disk, that are most likely remnants from an unknown baby galaxy that was swallowed by the Milky Way over 10 billion years ago. Nothing like it has been discovered in the galaxy disk before.

After the Big Bang 13.8 billion years ago, space was a veritable Wild West. Stars formed inside huge gas clouds that collided and fused into larger and larger clouds. However, after a few billion years of space chaos, galaxy embryos became more stable, eventually evolving into well-ordered spiral galaxies, such as the Milky Way. In a new study on the origins of the Milky Way, published in Astrophysical Journal, a research team has made a surprising discovery.

“We have found traces of a smaller galaxy that was swallowed by the Milky Way. This intergalactic relic was indirectly discovered through a population of ten-billion-year-old stars in the Milky Way's disk. This is the first time such old stars have been found in the disk that show signs of coming from another galaxy”, says Diane Feuillet, astronomer at Lund University who led the study.

Native Americans Name Asteroid 'Ayló'chaxnim or 'Venus Girl'

Members of the Pauma band pose inside the dome of the 200-inch Hale Telescope.
Credit: Palomar Observatory/Caltech

On June 7, at Caltech's Palomar Observatory in the forested mountain outside San Diego, members of the Pauma band of indigenous peoples gathered to celebrate the naming of the first known asteroid to circle entirely within the orbit of Venus. The asteroid was originally discovered in 2020 by the Zwicky Transient Facility, or ZTF, which operates at the Palomar Observatory. Sometime after its discovery, the ZTF team decided to ask the Pauma band, whose ancestral lands include the mountainous region where the observatory is located, if they would like to bestow the new cosmic find with a name of their choosing.

Ultimately, the indigenous group chose to name the asteroid 'Ayló'chaxnim, which means "Venus girl" in their native language of Luiseño.

The Palomar naming ceremony included blessings, traditional Pauma songs, and a reading of a poem titled Luiseño Songs of the Seasons, which describes how "it will soon be time for the acorns to fall from the trees" when "Venus is rising."

Ground-breaking number of brown dwarfs discovered

Image of the brown dwarf (in the red circle) discovered around the star HIP 21152, obtained with the Very Large Telescope SPHERE instrument.
Credit: M. Bonavita et al., MNRAS

Brown dwarfs, mysterious objects that straddle the line between stars and planets, are essential to our understanding of both stellar and planetary populations. However, only 40 brown dwarfs could be imaged around stars in almost three decades of searches. An international team led by researchers from the Open University and the University of Bern directly imaged a remarkable four new brown dwarfs thanks to a new innovative search method.

Brown dwarfs are mysterious astronomical objects that fill the gap between the heaviest planets and the lightest stars, with a mix of stellar and planetary characteristics. Due to this hybrid nature, these puzzling objects are crucial to improve our understanding of both stars and giant planets. Brown dwarfs orbiting a parent star from sufficiently far away are particularly valuable as they can be directly photographed – unlike those that are too close to their star and are thus hidden by its brightness. This provides scientists with a unique opportunity to study the details of the cold, planet-like atmospheres of brown dwarf companions.

Earth Is Safe: Astronomers Conducted a "Space Exercise"

Today, the distance from Apophis to Earth is 0.88 astronomical units, or almost 132 million km.
Photo: Eyes on Asteroids / NASA

More than 100 astronomers from 18 countries conducted a "space exercise". They joined their efforts to simulate the approach to the Earth of a dangerous asteroid and to estimate the probability of collision. Employees of the Kourovka Astronomical Observatory of the UrFU also took part in the project: Eduard Kuznetsov, Dmitry Glamazda, Galina Kaiser, Aleksandr Perminov and Yulia Vibe. The study was led by experts from NASA and the International Asteroid Warning Network (IAWN). The results are published in the Planetary Science Journal.

The asteroid Apophis, which was approaching Earth from December 2020 to March 2021, was taken as a sample of the potential threat. According to the "exercises", all data on Apophis were "forgotten", and scientists had to detect the asteroid again, determine its coordinates, speed, trajectory and many other parameters, as well as estimate the probability of collision with the Earth, the strength (energy) of the hit, which can cause an asteroid like Apophis. By common efforts it was even possible to determine the general composition of the asteroid and the properties of its surface. It was crucial, however, to understand how far in advance scientists were able to detect and how quickly they could classify extraterrestrial bodies that could pose a danger to the Earth.

Colossal collisions linked to solar system science

In this composite image of Abell 2146, Chandra X-ray data (purple) shows hot gas, and Subaru Telescope optical data shows galaxies (red and white).
Credit: Chandra X-ray / NASA

A new study shows a deep connection between some of the largest, most energetic events in the universe and much smaller, weaker ones powered by our own Sun.

The results come from a long observation with NASA’s Chandra X-ray Observatory of Abell 2146, a pair of colliding galaxy clusters located about 2.8 billion light-years from Earth. The new study was led by Helen Russell from the School of Physics and Astronomy and has been published online by The Monthly Notices of the Royal Astronomical Society

Galaxy clusters contain hundreds of galaxies and huge amounts of hot gas and dark matter and are among the largest structures in the universe. Collisions between galaxy clusters release enormous amounts of energy unlike anything witnessed since the big bang and provide scientists with physics laboratories that are unavailable here on Earth.

The shock wave is about 1.6 million light-years long and is most easily seen in a version of the X-ray image that has been processed to emphasize sharp features. Also labeled are the central core of hot gas in cluster #2, and the tail of gas it has left behind. A second shock wave of similar size is seen behind the collision. Called an “upstream shock,” features like this arise from the complex interplay of stripped gas from the infalling cluster and the surrounding cluster gas. The brightest and most massive galaxy in each cluster is also labeled.

Evidence of galactic metal shrouded in dust

NASA’s SOFIA airborne observatory enabled a UCI-led team of astronomers to study infrared emissions from five nearby galaxies. The researchers found more metal than expected in the intergalactic medium, a result that would have been difficult to achieve without the power of viewing infrared radiation through thick galactic dust.
Credit: Jim Ross / NASA

A thorough understanding of galaxy evolution depends in part on an accurate measurement of the abundance of metals in the intergalactic medium – the space between stars – but dust can impede observations in optical wavelengths. An international team of astronomers at the University of California, Irvine, Oxford University in England, and other institutions uncovered evidence of heavier elements in local galaxies – found to be deficient in earlier studies – by analyzing infrared data gathered during a multiyear campaign.

For a paper published recently in Nature Astronomy, the researchers examined five galaxies that are dim in visible wavelengths but trillions of times more luminous than the sun in the infrared. Interactions between these galaxies and neighboring star systems cause gas to shift around and collapse, setting up conditions for prodigious star formation.

“Studying the gas content of these galaxies with optical instruments, astronomers were convinced that they were significantly metal-poor when compared with other galaxies of similar mass,” said lead author Nima Chartab, UCI postdoctoral scholar in physics & astronomy. “But when we observed emission lines of these dusty galaxies in infrared wavelengths, we were afforded a clear view of them and found no significant metal deficiency.”

Astronomers identify 116,000 new variable stars

An ASAS-SN telescope helps astronomers discover new stars.
Photo: ASAS-SN

Ohio State University astronomers have identified about 116,000 new variable stars, according to a new paper.

These heavenly bodies were found by The All-Sky Automated Survey for Supernovae (ASAS-SN), a network of 20 telescopes around the world which can observe the entire sky about 50,000 times deeper than the human eye. Researchers from Ohio State have operated the project for nearly a decade.

Now in a paper published on arXiv, an open-access preprint server, researchers describe how they used machine learning techniques to identify and classify variable stars — celestial objects whose brightness waxes and wanes over time, especially if observed from our perspective on Earth.

The changes these stars undergo can reveal important information about their mass, radius, temperature and even their composition. In fact, even our sun is considered a variable star. Surveys like ASAS-SN are an especially important tool for finding systems that can reveal the complexities of stellar processes, said Collin Christy, the lead author of the paper and an ASAS-SN analyst at Ohio State.

“Variable stars are sort of like a stellar laboratory,” he said. “They’re really neat places in the universe where we can study and learn more about how stars actually work and the little intricacies that they all have.”

Asteroid Institute Uses Revolutionary Cloud-Based Astrodynamics Platform to Discover and Track Asteroids

The Asteroid Institute, a program of B612 Foundation, today announced it is using a groundbreaking computational technique running on its Asteroid Discovery Analysis and Mapping (ADAM) cloud-based astrodynamics platform to discover and track asteroids. The Minor Planet Center has confirmed and added the first 104 of these newly discovered asteroids to its registry, thus opening the door for Asteroid Institute-supported researchers to submit thousands of additional new discoveries.

The ADAM platform is an open-source computational system that runs astrodynamics algorithms using the scalable computational and storage capabilities in Google Compute Engine, Google Cloud Storage, and Google Kubernetes Engine. The novel algorithm used to discover these new asteroids is called THOR (Tracklet-less Heliocentric Orbit Recovery), and it links points of light in different sky images that are consistent with asteroid orbits. Unlike current state-of-the-art algorithms, THOR does not require the telescope to observe the sky in a particular pattern for asteroids to be discoverable. Researchers can now begin systematic explorations of large datasets that were previously not usable for discovering asteroids. THOR recognizes asteroids, and most importantly, calculates their orbits well enough to be recognized by the Minor Planet Center as tracked asteroids.

For its initial demonstration, Joachim Moeyens, THOR co-creator and the Asteroid Institute Graduate Student Fellow at the University of Washington, searched a 30-day window of images from the NOIRLab Source Catalog (NSC), a collection of nearly 68 billion observations taken by the National Optical Astronomy Observatory telescopes between 2012 and 2019. From this Moeyens submitted a small, initial subset of discoveries to the Minor Planet Center for official recognition and validation. Now that the computational discovery technique has been validated, thousands of new discoveries from NSC and other datasets are expected to follow.

The Sun is spinning round again

The model developed by the scientists includes the history of the rotation of the sun but also the magnetic instabilities that it generates.
Credit: Sylvia Ekström / UNIGE

All was amiss with the Sun! In the early 2000s, a new set of data brought down the chemical abundances at the surface of the Sun, contradicting the values predicted by the standard models used by astrophysicists. Often challenged, these new abundances made it through several new analyses. As they seemed to prove correct, it was thus up to the solar models to adapt, especially since they serve as a reference for the study of stars in general. A team of astronomers from the University of Geneva, Switzerland (UNIGE) in collaboration with the Université de Liège, has developed a new theoretical model that solves part of the problem: considering the Sun’s rotation, that varied through time, and the magnetic fields it generates, they have been able to explain the chemical structure of the Sun. The results of this study are published in Nature Astronomy.

“The Sun is the star that we can best characterize, so it constitutes a fundamental test for our understanding of stellar physics. We have abundance measurements of its chemical elements, but also measurements of its internal structure, like in the case of Earth thanks to seismology”, explains Patrick Eggenberger, a researcher at the Department of astronomy of the UNIGE and first author of the study.

These observations should fall in line with the results predicted by the theoretical models which aim at explaining the Sun’s evolution. How does the Sun burn its hydrogen in the core? How is energy produced there and then transported towards the surface? How do chemical elements drift within the Sun, influenced both by rotation and magnetic fields?

Geology from 50 Light-Years: Webb Gets Ready to Study Rocky Worlds

Comparison of Exoplanets 55 Cancri e and LHS 3844 b to Earth and Neptune
Credit: NASA, ESA, CSA, Dani Player (STScI)

With its mirror segments beautifully aligned and its scientific instruments undergoing calibration, NASA’s James Webb Space Telescope is just weeks away from full operation. Soon after the first observations are revealed this summer, Webb’s in-depth science will begin.

Among the investigations planned for the first year are studies of two hot exoplanets classified as “super-Earths” for their size and rocky composition: the lava-covered 55 Cancri e and the airless LHS 3844 b. Researchers will train Webb’s high-precision spectrographs on these planets with a view to understanding the geologic diversity of planets across the galaxy, and the evolution of rocky planets like Earth.

Stars are heavier than we thought

The Andromeda galaxy, our Milky Way's closest neighbor, is the most distant object in the sky that you can see with your unaided eye.
Credit: NASA and J. Olmsted (STScI)

A team of University of Copenhagen astrophysicists has arrived at a major result regarding star populations beyond the Milky Way. The result could change our understanding of a wide range of astronomical phenomena, including the formation of black holes, supernovae and why galaxies die.

For as long as humans have studied the heavens, how stars look in distant galaxies has been a mystery. In a study published today in The Astrophysical Journal, a team of researchers at the University of Copenhagen’s Niels Bohr Institute is doing away with previous understandings of stars beyond our own galaxy.

Since 1955, it has been assumed that the composition of stars in the universe's other galaxies is similar to that of the hundreds of billions of stars within our own – a mixture of massive, medium mass and low mass stars. But with the help of observations from 140,000 galaxies across the universe and a wide range of advanced models, the team has tested whether the same distribution of stars apparent in the Milky Way applies elsewhere. The answer is no. Stars in distant galaxies are typically more massive than those in our "local neighborhood". The finding has a major impact on what we think we know about the universe.

AI reveals unsuspected math underlying search for exoplanets

Artist’s concept of a sun-like star (left) and a rocky planet about 60% larger than Earth in orbit in the star’s habitable zone. Gravitational microlensing has the ability to detect such planetary systems and determine the masses and orbital distances, even though the planet itself is too dim to be seen. 
Image credit: NASA Ames/JPL-Caltech/T. Pyle

Artificial intelligence (AI) algorithms trained on real astronomical observations now outperform astronomers in sifting through massive amounts of data to find new exploding stars, identify new types of galaxies and detect the mergers of massive stars, accelerating the rate of new discovery in the world’s oldest science.

But AI, also called machine learning, can reveal something deeper, University of California, Berkeley, astronomers found: unsuspected connections hidden in the complex mathematics arising from general relativity — in particular, how that theory is applied to finding new planets around other stars.

In a paper appearing this week in the journal Nature Astronomy, the researchers describe how an AI algorithm developed to more quickly detect exoplanets when such planetary systems pass in front of a background star and briefly brighten it — a process called gravitational microlensing — revealed that the decades-old theories now used to explain these observations are woefully incomplete.

Planets of binary stars as possible homes for alien life

The ALMA telescopes in Chile
Credit: ESO/S. Guisard

Since the only known planet with life, the Earth, orbits the Sun, planetary systems around stars of similar size are obvious targets for astronomers trying to locate extraterrestrial life. Nearly every second star in that category is a binary star. A new result from research at University of Copenhagen indicates that planetary systems are formed in a very different way around binary stars than around single stars such as the Sun.

“The result is exciting since the search for extraterrestrial life will be equipped with several new, extremely powerful instruments within the coming years. This enhances the significance of understanding how planets are formed around different types of stars. Such results may pinpoint places which would be especially interesting to probe for the existence of life,” says Professor Jes Kristian Jørgensen, Niels Bohr Institute, University of Copenhagen, heading the project.

The results from the project, which also has participation of astronomers from Taiwan and USA, are published in the distinguished journal Nature.

Researchers Use Galaxy as a ‘Cosmic Telescope’ to Study Heart of the Young Universe

An artist’s rendering shows how a cluster of galaxies (lensing cluster) acts as a gravitational lens that magnifies and extends the light from a background galaxy.
Image: W. M. Keck Observatory/Adam Makarenko

A unique new instrument, coupled with a powerful telescope and a little help from nature, has given researchers the ability to peer into galactic nurseries at the heart of the young universe.

After the big bang some 13.8 billion years ago, the early universe was filled with enormous clouds of neutral diffuse gas, known as Damped Lyman-α systems, or DLAs. These DLAs served as galactic nurseries, as the gases within slowly condensed to fuel the formation of stars and galaxies. They can still be observed today, but it isn’t easy.

“DLAs are a key to understanding how galaxies form in the universe, but they are typically difficult to observe since the clouds are too diffuse and don’t emit any light themselves,” says Rongmon Bordoloi, assistant professor of physics at North Carolina State University and corresponding author of the research.

Currently, astrophysicists use quasars – supermassive black holes that emit light – as “backlight” to detect the DLA clouds. And while this method does allow researchers to pinpoint DLA locations, the light from the quasars only acts as small skewers through a massive cloud, hampering efforts to measure their total size and mass.

But Bordoloi and John O’Meara, chief scientist at the W.M. Keck Observatory in Kamuela, Hawaii, found a way around the problem by using a gravitationally lensed galaxy and integral field spectroscopy to observe two DLAs – and the host galaxies within – that formed around 11 billion years ago, not long after the big bang.

“Gravitationally lensed galaxies refer to galaxies that appear stretched and brightened,” Bordoloi says. “This is because there is a gravitationally massive structure in front of the galaxy that bends the light coming from it as it travels toward us. So, we end up looking at an extended version of the object – it’s like using a cosmic telescope that increases magnification and gives us better visualization.

“The advantage to this is twofold: One, the background object is extended across the sky and bright, so it is easy to take spectrum readings on different parts of the object. Two, because lensing extends the object, you can probe very small scales. For example, if the object is one light year across, we can study small bits in very high fidelity.”

Spectrum readings allow astrophysicists to “see” elements in deep space that are not visible to the naked eye, such as diffuse gaseous DLAs and the potential galaxies within them. Normally, gathering the readings is a long and painstaking process. But the team solved that issue by performing integral field spectroscopy with the Keck Cosmic Web Imager.

Integral field spectroscopy allowed the researchers to obtain a spectrum at every single pixel on the part of the sky it targeted, making spectroscopy of an extended object on the sky very efficient. This innovation combined with the stretched and brightened gravitationally lensed galaxy allowed the team to map out the diffuse DLA gas in the sky at high fidelity. Through this method the researchers were able to determine not only the size of the two DLAs, but also that they both contained host galaxies.

“I’ve waited most of my career for this combination: a telescope and instrument powerful enough, and nature giving us a bit of lucky alignments to study not one but two DLAs in a rich new way,” O’Meara says. “It’s great to see the science come to fruition.”

The DLAs are huge, by the way. With diameters greater than 17.4 kiloparsecs, they’re more than two thirds the size of the Milky Way galaxy today. For comparison, 13 billion years ago, a typical galaxy would have a diameter of less than 5 kiloparsecs. A parsec is 3.26 light years, and a kiloparsec is 1,000 parsecs, so it would take light about 56,723 years to travel across each DLA.

“But to me, the most amazing thing about the DLAs we observed is that they aren’t unique – they seem to have similarities in structure, host galaxies were detected in both, and their masses indicate that they contain enough fuel for the next generation of star formation,” Bordoloi says. “With this new technology at our disposal, we are going to be able to dig deeper into how stars formed in the early universe.”

The work appears in Nature and was supported by the National Aeronautics and Space Administration, the W.M. Keck Foundation and the National Science Foundation. The Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D) also contributed to the work.

Source/Credit: North Carolina State University | Tracey Peake

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Astronomers find ‘gold standard’ star in Milky Way

The star HD 222925 is a ninth-magnitude star located toward the southern constellation Tucana.
Image credit: The STScI Digitized Sky Survey

In our sun’s neighborhood of the Milky Way Galaxy is a relatively bright star, and in it, astronomers have been able to identify the widest range of elements in a star beyond our solar system yet.

The study, led by University of Michigan astronomer Ian Roederer, has identified 65 elements in the star, HD 222925. Forty-two of the elements identified are heavy elements that are listed along the bottom of the periodic table of elements.

Identifying these elements in a single star will help astronomers understand what’s called the “rapid neutron capture process,” or one of the major ways by which heavy elements in the universe were created. Their results are posted on arXiv and have been accepted for publication in the Astrophysical Journal Supplement Series.

“To the best of my knowledge, that’s a record for any object beyond our solar system. And what makes this star so unique is that it has a very high relative proportion of the elements listed along the bottom two-thirds of the periodic table. We even detected gold,” Roederer said. “These elements were made by the rapid neutron capture process. That’s really the thing we’re trying to study: the physics in understanding how, where and when those elements were made.”