It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Thursday, May 23, 2024
SPACE
First pictures from Euclid satellite reveal billions of orphan stars
UNIVERSITY OF NOTTINGHAM
IMAGE:
THE IMAGE, CAPTURED BY THE EUCLID SATELLITE, DEPICTS THE PERSEUS CLUSTER OF GALAXIES BATHED IN A GENTLE, SOFT BLUE LIGHT EMANATING FROM ORPHAN STARS. THESE ORPHAN STARS ARE DISPERSED THROUGHOUT THE CLUSTER, EXTENDING UP TO 2 MILLION LIGHT-YEARS FROM ITS CENTRE. THE CLUSTER GALAXIES STAND OUT AS LUMINOUS ELLIPTICAL SHAPES AGAINST THE DARK EXPANSE OF SPACE.
CREDIT: ESA/EUCLID/EUCLID CONSORTIUM/NASA, IMAGE PROCESSING BY M. MONTES (IAC) AND J.-C. CUILLANDRE (CEA PARIS-SACLAY)
The first scientific pictures from the Euclid satellite mission have revealed more than 1,500 billion orphan stars scattered throughout the Perseus cluster of galaxies.
Led by astronomers from the University of Nottingham, this discovery sheds light on the origins of these celestial wanderers.
The Perseus cluster, located 240 million light-years away from Earth, is one of the Universe's most massive structures, boasting thousands of galaxies. However, amidst this cosmic ensemble, the Euclid satellite captured faint ghostly light - the orphan stars - drifting between the cluster's galaxies.
Stars naturally form within galaxies, so the presence of orphan stars outside these structures raised intriguing questions about their origins.
Professor Nina Hatch, who led the project team, said, "We were surprised by our ability to see so far into the outer regions of the cluster and discern the subtle colours of this light. This light can help us map dark matter if we understand where the intracluster stars came from. By studying their colours, luminosity, and configurations, we found they originated from small galaxies."
The orphan stars are characterised by their bluish hue and clustered arrangement. Based on these distinctive features the astronomers involved in the study suggest that the stars were torn from the outskirts of galaxies and from the complete disruption of smaller cluster galaxies, known as dwarfs.
After being torn from their parent galaxies, the orphaned stars were expected to orbit around the largest galaxy within the cluster. However, this study revealed a surprising finding: the orphan stars instead circled a point between the two most luminous galaxies in the cluster.
Dr Jesse Golden-Marx, a Nottingham astronomer involved in the study, commented, "This novel observation suggests that the massive Perseus cluster may have recently undergone a merger with another group of galaxies. This recent merger could have induced a gravitational disturbance, causing either the most massive galaxy or the orphan stars to deviate from their expected orbits, thus resulting in the observed misalignment."
Dr Matthias Kluge, first author on the study, from the Max-Planck institute for Extraterrestrial Physics in Munich, Germany, stated: "This diffuse light is more than 100,000 times fainter than the darkest night sky on Earth. But it is spread over such a large volume that when we add it all up, it accounts for about 20% of the luminosity of the entire cluster."
ESA's Euclid mission is designed to explore the composition and evolution of the dark Universe. The space telescope will create a great map of the large-scale structure of the Universe across space and time by observing billions of galaxies out to 10 billion light-years, across more than a third of the sky. Euclid will explore how the Universe has expanded and how structure has formed over cosmic history, revealing more about the role of gravity and the nature of dark energy and dark matter.
Dr Mireia Montes, an astronomer from the Institute of Astrophysics on the Canary Islands involved in the study said, “This work was only possible thanks to Euclid’s sensitivity and sharpness”. Euclid’s revolutionary design means that it can take images with similar sharpness as the Hubble Space Telescope, but covering an area that is 175 times larger.
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Euclid: Early Release Observations — The intracluster light and intracluster globular clusters of the Perseus cluster.
ARTICLE PUBLICATION DATE
23-May-2024
NASA’s TESS finds intriguing world sized between Earth, Venus
NASA/GODDARD SPACE FLIGHT CENTER
IMAGE:
GLIESE 12 B, WHICH ORBITS A COOL RED DWARF STAR LOCATED JUST 40 LIGHT-YEARS AWAY, PROMISES TO TELL ASTRONOMERS MORE ABOUT HOW PLANETS CLOSE TO THEIR STARS RETAIN OR LOSE THEIR ATMOSPHERES. IN THIS ARTIST’S CONCEPT, GLIESE 12 B IS SHOWN RETAINING A THIN ATMOSPHERE.
Using observations by NASA’s TESS (Transiting Exoplanet Survey Satellite) and many other facilities, two international teams of astronomers have discovered a planet between the sizes of Earth and Venus only 40 light-years away. Multiple factors make it a candidate well-suited for further study using NASA’s James Webb Space Telescope.
TESS stares at a large swath of the sky for about a month at a time, tracking the brightness changes of tens of thousands of stars at intervals ranging from 20 seconds to 30 minutes. Capturing transits — brief, regular dimmings of stars caused by the passage of orbiting worlds — is one of the mission’s primary goals.
“We’ve found the nearest, transiting, temperate, Earth-size world located to date,” said Masayuki Kuzuhara, a project assistant professor at the Astrobiology Center in Tokyo, who co-led one research team with Akihiko Fukui, a project assistant professor at the University of Tokyo. “Although we don’t yet know whether it possesses an atmosphere, we’ve been thinking of it as an exo-Venus, with similar size and energy received from its star as our planetary neighbor in the solar system.”
The host star, called Gliese 12, is a cool red dwarf located almost 40 light-years away in the constellation Pisces. The star is only about 27% of the Sun’s size, with about 60% of the Sun’s surface temperature. The newly discovered world, named Gliese 12 b, orbits every 12.8 days and is Earth’s size or slightly smaller — comparable to Venus. Assuming it has no atmosphere, the planet has a surface temperature estimated at around 107 degrees Fahrenheit (42 degrees Celsius).
Astronomers say that the diminutive sizes and masses of red dwarf stars make them ideal for finding Earth-size planets. A smaller star means greater dimming for each transit, and a lower mass means an orbiting planet can produce a greater wobble, known as “reflex motion,” of the star. These effects make smaller planets easier to detect.
The lower luminosities of red dwarf stars also means their habitable zones — the range of orbital distances where liquid water could exist on a planet’s surface — lie closer to them. This makes it easier to detect transiting planets within habitable zones around red dwarfs than those around stars emitting more energy.
The distance separating Gliese 12 and the new planet is just 7% of the distance between Earth and the Sun. The planet receives 1.6 times more energy from its star as Earth does from the Sun and about 85% of what Venus experiences.
“Gliese 12 b represents one of the best targets to study whether Earth-size planets orbiting cool stars can retain their atmospheres, a crucial step to advance our understanding of habitability on planets across our galaxy,” said Shishir Dholakia, a doctoral student at the Centre for Astrophysics at the University of Southern Queensland in Australia. He co-led a different research team with Larissa Palethorpe, a doctoral student at the University of Edinburgh and University College London.
Both teams suggest that studying Gliese 12 b may help unlock some aspects of our own solar system’s evolution.
“It is thought that Earth’s and Venus’s first atmospheres were stripped away and then replenished by volcanic outgassing and bombardments from residual material in the solar system,” Palethorpe explained. “The Earth is habitable, but Venus is not due to its complete loss of water. Because Gliese 12 b is between Earth and Venus in temperature, its atmosphere could teach us a lot about the habitability pathways planets take as they develop.”
One important factor in retaining an atmosphere is the storminess of its star. Red dwarfs tend to be magnetically active, resulting in frequent, powerful X-ray flares. However, analyses by both teams conclude that Gliese 12 shows no signs of extreme behavior.
During a transit, the host star’s light passes through any atmosphere. Different gas molecules absorb different colors, so the transit provides a set of chemical fingerprints that can be detected by telescopes like Webb.
“We know of only a handful of temperate planets similar to Earth that are both close enough to us and meet other criteria needed for this kind of study, called transmission spectroscopy, using current facilities,” said Michael McElwain, a research astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and a co-author of the Kuzuhara and Fukui paper. “To better understand the diversity of atmospheres and evolutionary outcomes for these planets, we need more examples like Gliese 12 b.”
TESS is a NASA Astrophysics Explorer mission managed by NASA Goddard and operated by MIT in Cambridge, Massachusetts. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA’s Ames Research Center in California’s Silicon Valley; the Center for Astrophysics | Harvard & Smithsonian in Cambridge, Massachusetts; MIT’s Lincoln Laboratory; and the Space Telescope Science Institute in Baltimore. More than a dozen universities, research institutes, and observatories worldwide are participants in the mission.
Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Transmission Spectroscopy
ARTICLE PUBLICATION DATE
23-May-2024
Potentially habitable 'exo-Venus' with Earth-like temperature discovered
ROYAL ASTRONOMICAL SOCIETY
Astronomers have made the rare and tantalising discovery of an Earth-like exoplanet 40 light-years away that may be just a little warmer than our own world.
The potentially-habitable planet, named Gliese 12 b, orbits its host star every 12.8 days, is comparable in size to Venus - so slightly smaller than Earth - and has an estimated surface temperature of 42°C (107°F), which is lower than most of the 5,000-odd exoplanets confirmed so far.
That is assuming it has no atmosphere, however, which is the crucial next step to establishing if it is habitable.
It may have an Earth-like atmosphere, one more akin to Venus - which experienced a runaway greenhouse effect that made it a 400°C (752°F) hellhole - no atmosphere, or perhaps a different kind of atmosphere not found in our solar system.
Getting an answer is vital because it would reveal if Gliese 12 b can maintain temperatures suitable for liquid water - and possibly life - to exist on its surface, while also unlocking answers about how and why Earth and Venus evolved so differently.
Gliese 12 b is by no means the first Earth-like exoplanet to have been discovered, but as NASA has said, there are only a handful of worlds like it that warrant a closer look.
It has been billed as "the nearest, transiting, temperate, Earth-size world located to date" and a potential target for further investigation by the US space agency's £7.5billion James Webb Space Telescope.
The closest Earth-like exoplanet to us - and possibly the most famous - is Proxima Centauri b, which is only 4 light-years away. However, because it is not a transiting world we still have a lot to learn about it, including whether it has an atmosphere and the potential to harbour life.
Most exoplanets are discovered using the transit method, where a planet passes in front of its star from our point of view, causing a dip in the host star's brightness.
During a transit, the star's light also passes through an exoplanet's atmosphere and some wavelengths get absorbed. Different gas molecules absorb different colours, so the transit provides a set of chemical fingerprints that can be detected by telescopes like Webb.
Gliese 12 b could also be significant because it may help reveal whether the majority of stars in our Milky Way galaxy - i.e. cool stars - are capable of hosting temperate planets that have atmospheres and are therefore habitable.
It orbits a cool red dwarf star called Gliese 12, which is almost 40 light-years away from Earth in the constellation Pisces.
"Gliese 12 b represents one of the best targets to study whether Earth-size planets orbiting cool stars can retain their atmospheres, a crucial step to advance our understanding of habitability on planets across our galaxy," said Shishir Dholakia, a doctoral student at the Centre for Astrophysics at the University of Southern Queensland in Australia.
He co-led a research team with Larissa Palethorpe, a doctoral student at the University of Edinburgh and University College London.
The exoplanet's host star is about 27 per cent of the size of our Sun and has a surface temperature that is around 60 per cent of our own star.
However, the distance separating Gliese 12 and the new planet is just 7 per cent of the distance between Earth and the Sun. Gliese 12 b therefore receives 1.6 times more energy from its star as Earth does from the Sun and about 85 per cent of what Venus experiences.
This difference in solar radiation is important because it means the planet's surface temperature is highly dependent on its atmospheric conditions. As a comparison to Gliese 12 b's estimated surface temperature of 42°C (107°F), Earth has an average surface temperature of 15°C (59°F).
"Atmospheres trap heat and - depending on the type - can change the actual surface temperature substantially," Dholakia explained. "We are quoting the planet's 'equilibrium temperature', which is the temperature the planet would be if it had no atmosphere.
"Much of the scientific value of this planet is to understand what kind of atmosphere it could have. Since Gliese 12 b gets in between the amount of light as Earth and Venus get from the Sun, it will be valuable for bridging the gap between these two planets in our solar system."
Palethorpe added: "It is thought that Earth's and Venus's first atmospheres were stripped away and then replenished by volcanic outgassing and bombardments from residual material in the solar system.
"The Earth is habitable, but Venus is not due to its complete loss of water. Because Gliese 12 b is between Earth and Venus in temperature, its atmosphere could teach us a lot about the habitability pathways planets take as they develop."
The researchers, along with another team in Tokyo, used observations by NASA's TESS (Transiting Exoplanet Survey Satellite) to help make their discovery.
"We've found the nearest, transiting, temperate, Earth-size world located to date," said Masayuki Kuzuhara, a project assistant professor at the Astrobiology Center in Tokyo, who co-led a research team with Akihiko Fukui, a project assistant professor at the University of Tokyo.
"Although we don't yet know whether it possesses an atmosphere, we've been thinking of it as an exo-Venus, with similar size and energy received from its star as our planetary neighbour in the solar system."
An important factor in retaining an atmosphere is the storminess of its star. Red dwarfs tend to be magnetically active, resulting in frequent, powerful X-ray flares.
However, analyses by both teams conclude that Gliese 12 shows no signs of such extreme behaviour, raising hopes that Gliese 12 b's atmosphere may still be intact.
"We know of only a handful of temperate planets similar to Earth that are both close enough to us and meet other criteria needed for this kind of study, called transmission spectroscopy, using current facilities," said Michael McElwain, a research astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and a co-author of the Kuzuhara and Fukui paper.
"To better understand the diversity of atmospheres and evolutionary outcomes for these planets, we need more examples like Gliese 12 b."
At 40 light-years from Earth, Gliese 12 b is about the same distance as the TRAPPIST-1 system.
This is made up of seven planets, all roughly in Earth's size range and likely rocky, orbiting a red dwarf star.
Three of these are in the habitable zone but at least two - and probably all of them - have no atmosphere and are likely barren, dismissing hopes when they were first discovered eight years ago that they could be water worlds hosting life.
Gliese 12 b’s estimated size may be as large as Earth or slightly smaller — comparable to Venus in our solar system. This artist’s concept compares Earth with different possible Gliese 12 b interpretations, from one with no atmosphere to one with a thick Venus-like one.
Caption: Gliese 12 b, which orbits a cool, red dwarf star located just 40 light-years away, promises to tell astronomers more about how planets close to their stars retain or lose their atmospheres. In this artist's concept, Gliese 12 b is shown retaining a thin atmosphere.
Caption: Gliese 12 b's estimated size may be as large as Earth or slightly smaller — comparable to Venus in our solar system. This artist's concept compares Earth with different possible Gliese 12 b interpretations, from one with no atmosphere to one with a thick Venus-like one.
Credit: NASA/JPL-Caltech/R. Hurt (Caltech-IPAC)
Further information
The new study "Gliese 12 b, A Temperate Earth-sized Planet at 12 Parsecs Discovered with TESS and CHEOPS", Shishir Dholakia and Larissa Palethorpe et al., has been published in the Monthly Notices of the Royal Astronomical Society.
It will be available here when the embargo lifts. To request a copy of the paper in advance, email stonkin@ras.ac.uk.
Notes for editors
About the Royal Astronomical Society
The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science.
The RAS organises scientific meetings, publishes international research and review journals, recognises outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4,000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.
The RAS accepts papers for its journals based on the principle of peer review, in which fellow experts on the editorial boards accept the paper as worth considering. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.
Potentially habitable 'exo-Venus' with Earth-like temperature discovered
ARTICLE PUBLICATION DATE
23-May-2024
Scientists reveal first data from Euclid telescope offering snapshot of cosmic history
UNIVERSITY OF MANCHESTER
Scientists have released the first set of scientific data captured with the Euclid telescope, showing an exciting glimpse of the Universe’s distant past.
The telescope, launched in July 2023, is part of the Dark Energy Satellite Mission, which aims to map the dark Universe.
Led by the European Space Agency in collaboration with The Euclid Consortium - which includes astronomers at The University of Manchester in leadership positions – the mission seeks to unlock mysteries of dark matter and dark energy and reveal how and why the Universe looks as it does today.
Early observations, described in a series of 10 scientific papers published today, include five never-before-seen images of the Universe.
The papers also describe several new discoveries including, free-floating new-born planets, newly identified extragalactic star clusters, new low-mass dwarf galaxies in a nearby galaxy cluster, the distribution of dark matter and intracluster light in galaxy clusters, and very distant bright galaxies from the first billion years of the Universe.
The findings give an insight into the unprecedented power of the Euclid telescope, which is designed to provide the most precise map of our Universe over time and demonstrates Euclid’s ability to unravel the secrets of the cosmos.
Chrisopher Conselice, Professor of Extragalactic Astronomy at The University of Manchester, said: “Euclid will completely revolutionise our view of the Universe. Already these results are revealing important new findings about local galaxies, new unknown dwarf galaxies, extrasolar planets and some of the first galaxies. These results are only the tip of the iceberg in terms of what will come. Soon Euclid will discover yet unknown details of the dark energy and give a full picture of how galaxy formation occurred across all cosmic time.”
Michael Brown, Professor of Astrophysics at The University of Manchester, added: “The exceptional data that Euclid is delivering over a large fraction of the sky promises to revolutionise our understanding of dark energy. It is extremely exciting to be part of the team working to extract these headline science results.”
The Early Release Observations programme was conducted during Euclid’s first months in space as a first look at the depth and diversity of science Euclid will provide. A total of 24 hours were allocated to target 17 specific astronomical objects, from nearby clouds of gas and dust to distant clusters of galaxies, producing stunning images that are invaluable for scientific research. In just a single day, Euclid produced a catalogue of more than 11 million objects in visible light and five million more in infrared light.
In addition to contributions to the mission’s primary objectives, scientists at The University of Manchester, in collaboration with the University of Massachusetts Amherst, conducted a preliminary search of the data for distant galaxies. The red galaxies in the image show the cluster, which acts as a magnifying glass to reveal more distant sources behind. In total, 29 galaxies were discovered providing insight into the first billion years of the Universe.
Dr Rebecca Bowler, Ernest Rutherford Fellow at The University of Manchester, said: “In these spectacular images we can see galaxies that were previously invisible, because the most distant galaxies can only be discovered using the longer near-infrared wavelengths seen by Euclid.
“This first look data has been invaluable to test our search algorithms and identifying challenges, such as confusion of distant galaxies with brown dwarfs in our own Milky Way, before we start working on the main data later this year.
“What is amazing is that these images cover an area of less than 1% of the full deep observations, showing that we expect to detect thousands of early galaxies in the next few years with Euclid, which will be revolutionary in understanding how and when galaxies formed after the Big Bang.”
The images obtained by Euclid are at least four times sharper than those that can be taken from ground-based telescopes. They cover large patches of sky at unrivalled depth, looking far into the distant Universe using both visible and infrared light.
The next data release from the Euclid Consortium will focus on Euclid’s primary science objectives. A first worldwide quick release is currently planned for March 2025, while a wider data release is scheduled for June 2026. At least three other quick releases and two other data releases are expected before 2031, which corresponds to a few months after the end of Euclid’s initial survey.
The Euclid Consortium comprises more than 2600 members, including over 1000 researchers from more than 300 laboratories in 15 European countries, plus Canada, Japan and United States, covering various fields in astrophysics, cosmology, theoretical physics, and particle physics.
Josef Aschbacher, ESA Director General, said: “Euclid demonstrates European excellence in frontier science and state-of-the-art technology, and showcases the importance of international collaboration.
“The mission is the result of many years of hard work from scientists, engineers and industry throughout Europe and from members of the Euclid scientific consortium around the world, all brought together by ESA. They can be proud of this achievement – the results are no small feat for such an ambitious mission and such complex fundamental science. Euclid is at the very beginning of its exciting journey to map the structure of the Universe.”
UH astronomers uncover array of strange exoplanet worlds
ARTIST’S RENDITION OF A VARIETY OF EXOPLANETS FEATURED IN THE NEW NASA TESS-KECK SURVEY MASS CATALOG, THE LARGEST HOMOGENOUS ANALYSIS OF TESS PLANETS RELEASED BY ANY SURVEY THUS FAR.
An international scientific team, with major contributions by astronomers at the University of Hawaiʻi Institute for Astronomy (IfA), has announced a new catalog of 120 confirmed and six new candidate exoplanets. They were discovered using NASA’s Transiting Exoplanet Survey Satellite (TESS), in collaboration with the W. M. Keck Observatory on Maunakea, Hawaiʻi.
With the TESS-Keck Survey’s Mass Catalog, astronomers now have a new database to explore the latest worlds found by TESS, paving the way for them to study their properties and environments in finer detail, particularly those planets that could harbor life as we know it.
The latest installment of the survey, in which UH is a major partner, provides thousands of radial velocity (RV) observations—a measurement of the reflex motion of a star due to an orbiting planet’s gravity. These observations reveal a fascinating mix of planet types beyond our solar system, from rare worlds with extreme environments to ones that could possibly support life.
“The TESS-Keck Survey demonstrates the very important role of ground-based observations for advancing our understanding of the Universe and in this case, planets outside our system”, said Dan Huber, an associate astronomer at IfA who co-authored the paper and is a co-principal investigator of the TESS-Keck Survey. “Space telescopes like TESS can tell us about the sizes of planets, but follow-up observations such as those obtained with Keck provide mass measurements that are required to learn about what these planets are made of.”
Ground-based insights
Huber and fellow IfA astronomer Fei Dai, and IfA alumna Ashley Chontos, partnered with a global team of astronomers to develop the new exoplanet catalog, which took TESS planetary data and analyzed 9,204 RV measurements. More than half of the measurements were taken over the course of 301 observing nights using Keck Observatory’s planet-hunting spectrometer instrument.
“The results that have come from the TESS-Keck Survey represent the single largest contribution to understanding the physical nature and system architectures of new planets TESS has discovered,” said Alex Polanski, a physics and astronomy graduate student at the University of Kansas who is the paper’s lead author. “Catalogs like this help astronomers place individual worlds in context with the rest of the exoplanet population.”
The team also obtained additional radial velocities using the University of California Observatories’ Automated Planet Finder at Lick Observatory.
With all of the RVs combined, they were able to calculate the masses of 120 confirmed planets plus six candidate planets.
Exploring alien worlds
The TESS-Keck Survey revealed a vast diversity of exotic worlds. UH astronomers honed in on planets orbiting so-called subgiant stars—future versions of the Sun. In a companion paper, Chontos, a former IfA graduate student who is now a postdoctoral fellow at Princeton, led the largest homogeneous study of such planets to date.
“The Sun will eventually expand into a giant star after it has fused all hydrogen in its core,” said Chontos. “We have some ideas for what might happen to the planets in our solar system but by directly observing these more evolved systems, we can begin to put together the puzzle pieces and tie the observations to the theory.”
The results may help predict the future fate of our planet when the Sun swells up and possibly engulfs the Earth. In particular, the study bridges the gap to other systems that have been shown to have somehow survived this fate or are currently in the process of being engulfed.
In another example of extreme worlds, Dai and Caltech student Ryan Rubenzahl discovered the largest rocky planet ever found (TOI-1347 b). Their work suggests that planets with rocky surfaces like Earth likely cannot have masses much more than 10 times that of Earth. A larger planet would almost certainly accrete a thick envelope of lighter gasses (such as hydrogen and helium) from its nascent gas disk, and thus produce planets more similar to the icy giants or gas giants in our solar system.
Diverse Exoplanet Cornucopia
From Jupiter-sized, to Saturn-sized, Neptune-like, sub-Neptunes, and rocky Earth-like worlds, this artist’s rendition depicts the exoplanets detected by TESS then characterized by W. M. Keck Observatory and Lick Observatory; all are profiled in a newly-released catalog as part the TESS-Keck Survey.
Artist’s rendition of TOI-1798, a planetary system that is home to two planets. The new TESS-Keck Survey Mass Catalog shows the outer planet is a sub-Neptune with an orbital period of eight days; the inner planet is a strange Super-Earth that orbits so close to its star, one year on this alien world lasts only half an Earth day.
Artist’s rendition of TOI-1824, a star system with an exoplanet that’s unusually dense for its size. It is one of the densest sub-Neptunes profiled in the newly-released TESS-Keck Survey catalog.
CREDIT
W. M. Keck Observatory/Adam Makarenko
JOURNAL
The Astrophysical Journal
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
The TESS-Keck Survey. XX. 15 New TESS Planets and a Uniform RV Analysis of All Survey Targets
ARTICLE PUBLICATION DATE
23-May-2024
UMass Amherst astronomer leading international effort to understand evolutionary secrets of the universe
European Space Agency’s Euclid satellite releases first unprecedented wide-view, deep-scale, near-infrared views in search for dark matter and dark energy
UNIVERSITY OF MASSACHUSETTS AMHERST
IMAGE:
ABELL 2390 IS A GALAXY CLUSTER, A GIANT CONGLOMERATION OF MANY GALAXIES LIKE THE MILKY WAY. AROUND 50,000 GALAXIES CAN BE SEEN HERE. SUCH CLUSTERS CONTAIN HUGE AMOUNTS OF MASS, MUCH OF WHICH IS DARK MATTER. ABELL 2390 LIES 2.7 BILLION LIGHT-YEARS AWAY IN
CREDIT: ESA/EUCLID/EUCLID CONSORTIUM/NASA, IMAGE PROCESSING BY J.-C. CUILLANDRE (CEA PARIS-SACLAY), G. ANSELMI; CC BY-SA 3.0 IGO OR ESA STANDARD LICENCE.
AMHERST, Mass. – The European Space Agency (ESA) and the Euclid Consortium—a collaboration of 2,000 researchers from 300 institutions in 15 European countries, the U.S., Canada and Japan—recently released the first stunning images from the Euclid space telescope, launched in July 2023. Euclid’s mission is to trace the hidden web-like foundations of the cosmos, map billions of galaxies across more than one-third of the sky, explore how our Universe formed and evolved over cosmic history and study the most mysterious of its fundamental components: dark energy and dark matter. The University of Massachusetts Amherst’s astronomy department is leading the effort on behalf of the Euclid Consortium to understand the earliest days of the universe, and how we got to where we are today.
For John Weaver, a postdoctoral researcher in astronomy at UMass Amherst and the lead author of one of 10 papers describing Euclid’s findings, the satellite is helping him to look at things that shouldn’t exist—but do.
“We see galaxies in the nearby universe that have surprisingly large numbers of stars—in fact, they have an uncomfortable number of them, more than we think they should. Where did all these stars come from? Euclid is now showing us superbright galaxies in the early universe less than a billion years after the Big Bang —and they are much brighter than they should be, too. I want to find out if these superbright, very distant galaxies eventually evolve into today’s supermassive galaxies.”
The light from these galaxies took some 13 billion years to reach us, meaning that we see them as they were in their infancy shortly after their formation. Essentially, Weaver and his colleagues are able to look back in time.
A single Euclidimage contains both old supermassive galaxies that have ceased forming their stars and distant young galaxies forming lots of stars. It’s like being able to study an ancient fossil and a live dinosaur, all at the same time. “Is it plausible,” Weaver wonders, “that these superbright galaxies grow into the supermassive fossils?”
Unprecedented results
The images obtained by Euclid are at least four times sharper than those taken by ground-based telescopes. They cover large patches of sky unrivalled in scale, looking far into the distant universe using both visible and infrared light.
“It’s no exaggeration to say that the results we’re seeing from Euclid are unprecedented,” says ESA Director of Science Carole Mundell. “Euclid’s first images, published in November, clearly illustrated the telescope’s vast potential to explore the dark universe, and this second batch is no different.
“The beauty of Euclid is that it covers large regions of the sky in great detail and depth and can capture a wide range of different objects all in the same image – from faint to bright, from distant to nearby, from the most massive of galaxy clusters to small planets,” Mundell continues. “We get both a very detailed and very wide view all at once. This amazing versatility has resulted in numerous new science results that, when combined with the results from Euclid’s surveying over the coming years, will significantly alter our understanding of the universe.”
While visually stunning, the images are far more than beautiful snapshots; they reveal new physical properties of the universe thanks to Euclid’s unique observing capabilities.
Euclid produced the entire set of Early Release Observations in just a single day, revealing over 11 million objects in visible light and 5 million more in infrared light. Careful measurements of their light has resulted in significant new science.
“Euclid demonstrates European excellence in frontier science and state-of-the-art technology, and showcases the importance of international collaboration,” says ESA Director General Josef Aschbacher. “The mission is the result of many years of hard work from scientists, engineers and industry throughout Europe and from members of the Euclid scientific consortium around the world, all brought together by ESA. They can be proud of this achievement – the results are no small feat for such an ambitious mission and such complex fundamental science. Euclid is at the very beginning of its exciting journey to map the structure of the universe.”
About the images
Weaver and his colleagues focused on two galaxy clusters, Abell 2390 and Abell 2764.
Abell 2390
Euclid’s image of galaxy cluster Abell 2390 reveals more than 50,000 galaxies and shows a beautiful display of gravitational lensing, depicting giant curved arcs on the sky–some of which are actually multiple views of the same distant object. Euclid will use lensing (where the light travelling to us from distant galaxies is bent and distorted by gravity) as a key technique for exploring the dark universe, indirectly measuring the amount and distribution of dark matter both in galaxy clusters and elsewhere. Euclid scientists are also studying how the masses and numbers of galaxy clusters on the sky have changed over time, revealing more about the history and evolution of the universe. Euclid’s cutout view of Abell 2390 shows the light permeating the cluster from stars that have been ripped away from their parent galaxies and sit in intergalactic space. Viewing this “intracluster light” is a specialty of Euclid, and these stellar orphans may allow us to “see” where dark matter lies.
Abell 2764 (and bright star)
This view shows the galaxy cluster Abell 2764 (top right), which comprises hundreds of galaxies within a vast halo of dark matter and is approximately 1 billion light years away. Euclid captures many objects in this patch of sky, including background galaxies, more distant clusters and interacting galaxies throwing off streams and shells of stars. This complete view of Abell 2764 and surroundings—obtained thanks to Euclid’s impressively wide field-of-view—allows scientists to ascertain the radius of the cluster and see its outskirts with faraway galaxies still in frame. Euclid’s observations of Abell 2764 are also allowing scientists to further explore galaxies in the distant cosmic dark ages, as with Abell 2390.
Also seen here is a very bright foreground star that lies within our own galaxy (V*BP-Phoenicis, a star in the southern hemisphere that’s bright enough to be seen by the human eye). When we look at a star through a telescope, its light is scattered outwards into a diffuse circular halo due to the telescope’s optics. Euclid was designed to make this scatter as small as possible. As a result, the star causes little disturbance, allowing us to capture faint distant galaxies near the line of sight without being blinded by the star’s brightness.
Birth of universe’s earliest galaxies observed for first time
Using the James Webb Space Telescope, University of Copenhagen researchers have become the first to see the formation of three of the earliest galaxies in the universe, more than 13 billion years ago
UNIVERSITY OF COPENHAGEN - FACULTY OF SCIENCE
IMAGE:
KASPER E. HEINTZ, DARACH WATSON, GABRIEL BRAMMER & SIMONE VEJLGAARD FROM THE COSMIC DAWN CENTER, NIELS BOHR INSTITUTE, UNIVERSITY OF COPENHAGEN.
Using the James Webb Space Telescope, University of Copenhagen researchers have become the first to see the formation of three of the earliest galaxies in the universe, more than 13 billion years ago. The sensational discovery contributes important knowledge about the universe and is now published in the prestigious journal Science.
For the first time in the history of astronomy, researchers at the Niels Bohr Institute have witnessed the birth of three of the universe's absolute earliest galaxies, somewhere between 13.3 and 13.4 billion years ago.
The discovery was made using the James Webb Space Telescope, which brought these first 'live observations' of formative galaxies down to us here on Earth.
Through the telescope, researchers were able to see signals from large amounts of gas that accumulate and accrete onto a mini-galaxy in the process of being built. While this is how galaxies are formed according to theories and computer simulations, it had never actually been witnessed.
"You could say that these are the first 'direct' images of galaxy formation that we’ve ever seen. Whereas the James Webb has previously shown us early galaxies at later stages of evolution, here we witness their very birth, and thus, the construction of the first star systems in the universe," says Assistant Professor Kasper Elm Heintz from the Niels Bohr Institute, who led the new study.
The researchers estimate the birth of the three galaxies to have occurred roughly 400-600 million years after the Big Bang, the explosion that began it all. While that sounds like a long time, it corresponds to galaxies forming during the first three to four percent of the universe's 13.8-billion-year overall lifetime.
Shortly after the Big Bang, the universe was an enormous opaque gas of hydrogen atoms – unlike today, where the night sky is speckled with a blanket of well-defined stars.
"During the few hundred million years after the Big Bang, the first stars formed, before stars and gas began to coalesce into galaxies. This is the process that we see the beginning of in our observations," explains Associate Professor Darach Watson.
The birth of galaxies took place at a time in the history of the universe known as the Epoch of Reionization, when the energy and light of some of the first galaxies broke through the mists of hydrogen gas.
It is precisely these large amounts of hydrogen gas that the researchers captured using the James Webb Space Telescope’s infrared vision. This is the most distant measurement of the cold, neutral hydrogen gas, which is the building block of the stars and galaxies, discovered by scientific researchers to date.
Adds to the understanding of our origins
The study was conducted by Kasper Elm Heintz, in close collaboration with, among others, research colleagues Darach Watson, Gabriel Brammer and PhD student Simone Vejlgaard from the Cosmic Dawn Center at the University of Copenhagen’s Niels Bohr Institute – a center whose stated goal is to investigate and understand the dawn of the universe. This latest result brings them much closer to doing just that.
The research team has already applied for more observation time with the James Webb Space Telescope, with hopes of expanding upon their new result and learning more about the earliest epoch in the formation of galaxies.
"For now, this is about mapping our new observations of galaxies being formed in even greater detail than before. At the same time, we are constantly trying to push the limit of how far out into the universe we can see. So, perhaps we’ll reach even further," says Simone Vejlgaard.
According to the researcher, the new knowledge contributes to answering one of humanity’s most basic questions.
"One of the most fundamental questions that we humans have always asked is: 'Where do we come from?'. Here, we piece together a bit more of the answer by shedding light on the moment that some of the universe’s first structures were created. It is a process that we’ll investigate further, until hopefully, we are able to fit even more pieces of the puzzle together," concludes Associate Professor Gabriel Brammer.
The study was conducted by researchers Kasper E. Heintz, Darach Watson, Gabriel Brammer, Simone Vejlgaard, Anne Hutter, Victoria B. Strait, Jorryt Matthee, Pascal A. Oesch, Pall Jakobsson, Nial R. Tanvir, Peter Laursen, Rohan P. Naidu, Charlotte A. Mason, Meghana Killi, Intae Jung, Tiger Yu-Yang Hsiao, Abdurro'uf, Dan Coe, Pablo Arrabal Haro, Steven L. Finkelstein, & Sune Toft.
The Danish portion of the research is funded by the Danish National Research Foundation and the Carlsberg Foundation.
HOW THEY DID IT
Researchers were able to measure the formation of the universe’s first galaxies by using sophisticated models of how light from these galaxies was absorbed by the neutral gas located in and around them. This transition is known as the Lyman-alpha transition.
By measuring the light, the researchers were able to distinguish gas from the newly formed galaxies from other gas. These measurements were only possible thanks to the James Webb Space Telescope’s incredibly sensitive infrared spectrograph capabilities.
ABOUT THE EARLY UNIVERSE
The universe began its “life” about 13.8 billion years ago in an enormous explosion – the Big Bang. The event gave rise to an abundance of subatomic particles such as quarks and electrons. These particles aggregated to form protons and neutrons, which later coalesced into atomic nuclei. Roughly 380,000 years after the Big Bang, electrons began to orbit atomic nuclei, and the simplest atoms of the universe gradually formed.
The first stars were formed after a few hundred million years. And within the hearts of these stars, the larger and more complex atoms that we have around us were formed.
Later, stars coalesced into galaxies. The oldest galaxies known to us were formed about 3-400 million years after the Big Bang. Our own solar system came into being about 4.6 billion years ago – more than 9 billion years after the Big Bang.
Extreme damped Lyman-α absorption in young star-forming galaxies at z = 9 − 11
ARTICLE PUBLICATION DATE
24-May-2024
Galaxies actively forming in early universe caught feeding on cold gas
NASA/GODDARD SPACE FLIGHT CENTER
IMAGE:
THIS ILLUSTRATION SHOWS A GALAXY FORMING ONLY A FEW HUNDRED MILLION YEARS AFTER THE BIG BANG, WHEN GAS WAS A MIX OF TRANSPARENT AND OPAQUE DURING THE ERA OF REIONIZATION. DATA FROM NASA’S JAMES WEBB SPACE TELESCOPE SHOWS THAT COLD GAS IS FALLING ONTO THESE GALAXIES.
Researchers analyzing data from NASA’s James Webb Space Telescope have pinpointed three galaxies that may be actively forming when the universe was only 400 to 600 million years old. Webb’s data shows these galaxies are surrounded by gas that the researchers suspect to be almost purely hydrogen and helium, the earliest elements to exist in the cosmos. Webb’s instruments are so sensitive that they were able to detect an unusual amount of dense gas surrounding these galaxies. This gas will likely end up fueling the formation of new stars in the galaxies.
“These galaxies are like sparkling islands in a sea of otherwise neutral, opaque gas,” explained Kasper Heintz, the lead author and an assistant professor of astrophysics at the Cosmic Dawn Center (DAWN) at the University of Copenhagen in Denmark. “Without Webb, we would not be able to observe these very early galaxies, let alone learn so much about their formation.”
“We’re moving away from a picture of galaxies as isolated ecosystems. At this stage in the history of the universe, galaxies are all intimately connected to the intergalactic medium with its filaments and structures of pristine gas,” added Simone Nielsen, a co-author and PhD student also based at DAWN.
In Webb’s images, the galaxies look like faint red smudges, which is why extra data, known as spectra, were critical for the team’s conclusions. Those spectra show that light from these galaxies is being absorbed by large amounts of neutral hydrogen gas. “The gas must be very widespread and cover a very large fraction of the galaxy,” said Darach Watson, a co-author who is a professor at DAWN. “This suggests that we are seeing the assembly of neutral hydrogen gas into galaxies. That gas will go on to cool, clump, and form new stars.”
The universe was a very different place several hundred million years after the big bang during a period known as the Era of Reionization. Gas between stars and galaxies was largely opaque. Gas throughout the universe only became fully transparent around 1 billion years after the big bang. Galaxies’ stars contributed to heating and ionizing the gas around them, causing the gas to eventually become completely transparent.
By matching Webb’s data to models of star formation, the researchers also found that these galaxies primarily have populations of young stars. “The fact that we are seeing large gas reservoirs also suggests that the galaxies have not had enough time to form most of their stars yet,” Watson added.
This Is Only the Start
Webb is not only meeting the mission goals that drove its development and launch – it is exceeding them. “Images and data of these distant galaxies were impossible to obtain before Webb,” explained Gabriel Brammer, a co-author and associate professor at DAWN. “Plus, we had a good sense of what we were going to find when we first glimpsed the data – we were almost making discoveries by eye.”
There remain many more questions to address. Where, specifically, is the gas? How much is located near the centers of the galaxies – or in their outskirts? Is the gas pristine or already populated by heavier elements? Significant research lies ahead. “The next step is to build large statistical samples of galaxies and quantify the prevalence and prominence of their features in detail,” Heintz said.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
Strong damped Lyman-α absorption in young star-forming galaxies at redshifts 9 to 11
ARTICLE PUBLICATION DATE
23-May-
VIDEO: Surrey astrophysicists explore new galaxies and streams of stars using new data from Euclid space telescope
UNIVERSITY OF SURREY
As the European Space Agency publishes the first findings from its Euclid space telescope, scientists from the University of Surrey are celebrating fresh insights from the data.
Dr Denis Erkal, Associate Professor of Astrophysics at the University of Surrey, studies how the gravity of the Milky Way pulls clusters of stars apart, creating streams of stars trailing across the galaxy.
Now, his model for how this happens (video HERE) has been confirmed by data from Euclid.
Dr Erkal said:
“For a long time, my modelling predicted how the gravity of our Galaxy would pull apart clusters of stars like Messier 10.
“This first data from Euclid shows M10 behaving almost exactly as our models predicted it would. With future data from Euclid, we can explore how many of the star clusters in our Galaxy are getting pulled apart.
“Euclid has brought thousands of scientists together across hundreds of universities. By getting involved, Surrey has been able to continue our pioneering research into these streams of stars.”
Dr Erkal also worked with Dr Michelle Collins to help the Euclid team identify possible new galaxies in the telescope’s images.
Dr Collins said:
“These stunning first images are just the tip of the iceberg. Euclid’s powerful equipment can reveal small dwarf galaxies, identify free-floating rogue planets, and help us understand dark matter.
“This telescope can reveal millions of new objects in a single day. We’re only just beginning to realise its potential.”
ENDS
JOURNAL
Astronomy and Astrophysics
METHOD OF RESEARCH
Computational simulation/modeling
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Euclid : Early Release Observations – Deep anatomy of nearby galaxies
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