ESPRESSO and CARMENES discover two potentially habitable exo-Earths around a star near the Sun
“Nature seems bent on showing us that Earth-like planets are very common. With these two we now know 7 in planetary systems quite near to the Sun” explains Alejandro Suárez Mascareño, an IAC researcher, who is the first author of the study accepted for publication in Astronomy & Astrophysics.
The newly discovered planets orbit the star GJ 1002, which is at a distance of less than 16 light years from the Solar System. Both of them have masses similar to that of the Earth, and they are in the habitability zone of their star. GJ 1002b, the inner of the two, takes little more than 10 days to complete an orbit around the star, while GJ 1002c needs a little over 21 days. “GJ 1002 is a red dwarf star, with barely one eighth the mass of the Sun. It is quite a cool, faint star. This means that its habitability zone is very close to the star” explains Vera María Passegger, a co-author of the article and an IAC researcher.
The proximity of the star to our Solar System implies that the two planets, especially GJ 1002c, are excellent candidates for the characterization of their atmospheres based either on their reflected light, or on their thermal emission. “The future ANDES spectrograph for the ELT telescope at ESO in which the IAC is participating, could study the presence of oxygen in the atmosphere of GJ 1002c” notes Jonay I. González Hernández, an IAC researcher who is a co-author of the article. In addition, both planets satisfy the characteristics needed for them to be objectives for the future LIFE mission, which is presently in a study phase.
The discovery was made during a collaboration between the consortia of the two instruments ESPRESSO and CARMENES. GJ 1002 was observed by CARMENES between 2017 and 2019, and by ESPRESSO between 2019 and 2021. “Because of its low temperature the visible light from GJ 1002 is too faint to measure its variations in velocity with the majority of spectrographs” says says Ignasi Ribas, researcher at the Institute of Space Sciences (ICE-CSIC) and director of the Institut d'Estudis Espacials de Catalunya (IEEC). CARMENES has a sensitivity over a wide range of near infrared wavelengths which is superior to those of other spectrographs aimed at detecting variations in the velocities of stars, and this allowed it to study GJ 1002, from the 3.5m telescope at Calar Alto observatory.
The combination of ESPRESSO, and the light gathering power of the VLT 8m telescopes at ESO allowed measurements to be made with an accuracy of only 30 cm/sec, not attainable with any other instrument in the world. “Either of the two groups would have had many difficulties if they had tackled this work independently. Jointly we have been able to get much further than we would have done acting independently” states Suárez Mascareño.
JOURNAL
Astronomy and Astrophysics
ARTICLE TITLE
Two temperate Earth-mass planets orbiting the nearby star GJ 1002
Webb Space Telescope reveals previously shrouded newborn stars
Webb’s infrared camera peers through dust clouds, enabling discovery
Peer-Reviewed PublicationHOUSTON – (Dec. 16, 2022) – Rice University astronomer Megan Reiter and colleagues took a “deep dive” into one of the first images from NASA’s James Webb Space Telescope and were rewarded with the discovery of telltale signs from two dozen previously unseen young stars about 7,500 light years from Earth.
The published research in the December issue of the Monthly Notices of the Royal Astronomical Society offers a glimpse of what astronomers will find with Webb’s near-infrared camera. The instrument is designed to peer through clouds of interstellar dust that have previously blocked astronomers’ view of stellar nurseries, especially those that produce stars similar to Earth’s sun.
Reiter, an assistant professor of physics and astronomy, and co-authors from the California Institute of Technology, the University of Arizona, Queen Mary University in London and the United Kingdom’s Royal Observatory in Edinburgh, Scotland, analyzed a portion of Webb’s first images of the Cosmic Cliffs, a star-forming region in a cluster of stars known as NGC 3324.
“What Webb gives us is a snapshot in time to see just how much star formation is going on in what may be a more typical corner of the universe that we haven’t been able to see before,” said Reiter, who led the study.
Located in the southern constellation Carina, NGC 3324 hosts several well-known regions of star formation that astronomers have studied for decades. Many details from the region have been obscured by dust in images from the Hubble Space Telescope and other observatories. Webb’s infrared camera was built to see through dust in such regions and to detect jets of gas and dust that spew from the poles of very young stars.
Reiter and colleagues focused their attention on a portion of NGC 3324 where only a few young stars had previously been found. By analyzing a specific infrared wavelength, 4.7 microns, they discovered two dozen previously unknown outflows of molecular hydrogen from young stars. The outflows range in size, but many appear to come from protostars that will eventually become low-mass stars like Earth’s sun.
“The findings speak both to how good the telescope is and to how much there is going on in even quiet corners of the universe,” Reiter said.
Within their first 10,000 years, newborn stars gather material from the gas and dust around them. Most young stars eject a fraction of that material back into space via jets that stream out in opposite directions from their poles. Dust and gas pile up in front of the jets, which clear paths through nebular clouds like snowplows. One vital ingredient for baby stars, molecular hydrogen, gets swept up by these jets and is visible in Webb’s infrared images.
“Jets like these are signposts for the most exciting part of the star formation process,” said study co-author Nathan Smith of the University of Arizona. “We only see them during a brief window of time when the protostar is actively accreting.”
The accretion period of early star formation has been especially difficult for astronomers to study because it is fleeting — usually just a few thousand years in the earliest portion of a star’s multimillion-year childhood.
Study co-author Jon Morse of the California Institute of Technology said jets like those discovered in the study “are only visible when you embark on that deep dive — dissecting data from each of the different filters and analyzing each area alone.
“It’s like finding buried treasure,” Morse said.
Reiter said the size of the Webb telescope also played a role in the discovery.
“It's just a huge light bucket,” Reiter said. “That lets us see smaller things that we might have missed with a smaller telescope. And it also gives us really good angular resolution. So we get a level of sharpness that allows us to see relatively small features, even in faraway regions.”
The Webb Space Telescope program is led by NASA in partnership with the European Space Agency (ESA) and the Canadian Space Agency (CSA). The telescope’s science and mission operations are led by the Space Telescope Science Institute (STScI) in Baltimore.
The research was supported by NASA (NAS 5-0312, NAS 5–26555), STScI and a Dorothy Hodgkin Fellowship from the UK’s Royal Society.
-30-
Matter flows away from the poles of newborn stars in fast-moving columns that plow through nebular clouds. Gas and dust pile up in front of these outflows, forming waves called “bow shocks” in much the same way that bow waves form at the leading edge of seagoing ships. This false-color infrared image from the James Webb Space Telescope shows bow shocks of molecular hydrogen (red) streaming away from newborn stars in a star-forming region called the Cosmic Cliffs in the southern constellation Carina.
CREDIT
Image courtesy of NASA, ESA, CSA and STScI
Peer-reviewed paper:
“Deep diving off the ‘Cosmic Cliffs’: previously hidden outflows in NGC 3324 revealed by JWST” | Monthly Notices of the Royal Astronomical Society | DOI: 10.1093/mnras/stac2820
Megan Reiter, Jon A. Morse, Nathan Smith, Thomas J. Haworth, Michael A. Kuhn and Pamela D. Klaassen
https://doi.org/10.1093/mnras/stac2820
High-resolution IMAGES are available for download at:
https://news-network.rice.edu/news/files/2022/12/1215_COSMIC-f2a-lg.jpg
CAPTION: Astronomers from Rice University and other organizations dug deep into the data from this near-infrared image, one of the first taken by NASA’s James Webb Space Telescope. The image shows a star-forming region in the constellation Carina known as the Cosmic Cliffs. Many newborn stars in such regions are shrouded in thick clouds of dust. Webb’s infrared camera penetrated the dust, allowing astronomers to discover telltale signs of two dozen infant stars that hadn’t been previously detected. (Image courtesy of NASA, ESA, CSA and STScI)
https://news-network.rice.edu/news/files/2022/12/1215_COSMIC-mr9Fit-lg.jpg
CAPTION: Rice University astronomer Megan Reiter led a “deep dive” study of the earliest images from the James Webb Space Telescope. The research revealed telltale signs of two dozen previously uncataloged young stars in the star cluster NGC 3324 in the constellation Carina. (Photo by Jeff Fitlow/Rice University)
https://news-network.rice.edu/news/files/2022/12/1215_COSMIC-f2b-lg.jpg
CAPTION: Matter flows away from the poles of newborn stars in fast-moving columns that plow through nebular clouds. Gas and dust pile up in front of these outflows, forming waves called “bow shocks” in much the same way that bow waves form at the leading edge of seagoing ships. This false-color infrared image from the James Webb Space Telescope shows bow shocks of molecular hydrogen (red) streaming away from newborn stars in a star-forming region called the Cosmic Cliffs in the southern constellation Carina. (Image courtesy of NASA, ESA, CSA and STScI)
Related stories:
Gemini South’s high-def version of ‘A Star is Born’ – Oct. 5, 2020
https://news.rice.edu/news/2020/gemini-souths-high-def-version-star-born
Moon-forming disk discovered around distant planet - July 11, 2019
https://news2.rice.edu/2019/07/11/moon-forming-disk-discovered-around-distant-planet/
Direct from distant planet: Spectral clues to puzzling paradox – June 10, 2019
https://news2.rice.edu/2019/06/10/direct-from-distant-planet-spectral-clues-to-puzzling-paradox/
Carina Nebula survey reveals details of star formation – March 9, 2015
https://news2.rice.edu/2015/03/09/carina-nebula-survey-reveals-details-of-star-formation/
Hubble movies reveal solar-system-sized traffic jams – Aug. 31, 2011
https://news2.rice.edu/2011/09/07/hubble-movies-reveal-solar-system-sized-traffic-jams/
This release can be found online at news.rice.edu.
Follow Rice News and Media Relations via Twitter @RiceUNews.
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JOURNAL
Monthly Notices of the Royal Astronomical Society
METHOD OF RESEARCH
Data/statistical analysis
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Deep diving off the ‘Cosmic Cliffs’: previously hidden outflows in NGC 3324 revealed by JWST
JWST PEARLS project unveils exquisite views of distant galaxies
The press release and accompanying multimedia are available online on ASU News here
For decades, the Hubble Space Telescope and ground-based telescopes have provided us with spectacular images of galaxies. This all changed when the James Webb Space Telescope (JWST) launched in December 2021 and successfully completed commissioning during the first half of 2022. For astronomers, the universe, as we had seen it, is now revealed in a new way never imagined by the telescope's Near-Infrared Camera(NIRCam) instrument.
The NIRCam is Webb's primary imager that covers the infrared wavelength range from 0.6 to 5 microns. NIRCam detects light from the earliest stars and galaxies in the process of formation, the population of stars in nearby galaxies, as well as young stars in the Milky Way and Kuiper Belt objects.
The Prime Extragalactic Areas for Reionization and Lensing Science, or PEARLS, project is the subject of a recent study published in Astronomical Journal by a team of researchers, including Arizona State University School of Earth and Space Exploration Regents Professor Rogier Windhorst, Research Scientist Rolf Jansen, Associate Research Scientist Seth Cohen, Research Assistant Jake Summers and Graduate Associate Rosalia O'Brien, along with the contribution of many other researchers.
For researchers, the PEARLS program's images of the earliest galaxies show the amount of gravitational lensing of objects in the background of massive clusters of galaxies, allowing the team to see some of these very distant objects. In one of these relatively deep fields, the team has worked with stunning multicolor images to identify interacting galaxies with active nuclei.
Windhorst and his team's data show evidence for giant black holes in their center where you can see the accretion disc — the stuff falling into the black hole, shining very brightly in the galaxy center. Plus, lots of galactic stars show up like drops on your car's windshields — like you're driving through intergalactic space. This colorful field is straight up from the ecliptic plane, the plane in which the Earth and the moon, and all the other planets, orbit around the sun.
"For over two decades, I've worked with a large international team of scientists to prepare our Webb science program," Windhorst said. "Webb's images are truly phenomenal, really beyond my wildest dreams. They allow us to measure the number density of galaxies shining to very faint infrared limits and the total amount of light they produce. This light is much dimmer than the very dark infrared sky measured between those galaxies."
The first thing the team can see in these new images is that many galaxies that were next to or truly invisible to Hubble are bright in the images taken by Webb. These galaxies are so far away that the light emitted by stars has been stretched.
The team focused on the North Ecliptic Pole time domain field with the Webb telescope — easily viewed due to its location in the sky. Windhorst and the team plan to observe it four times.
The first observations, consisting of two overlapping tiles, produced an image that shows objects as faint as the brightness of 10 fireflies at the distance of the moon (with the moon not there). The ultimate limit for Webb is one or two fireflies. The faintest reddest objects visible in the image are distant galaxies that go back to the first few hundred million years after the Big Bang.
For most of Jansen's career, he's worked with cameras on the ground and in space, where you have a single instrument with a single camera that produces one image. Now scientists have an instrument that has not just one detector or one image coming out of it, but 10 simultaneously. For every exposure NIRCam takes, it gives 10 of these images. That's a massive amount of data, and the sheer volume can be overwhelming.
To process that data and channel it through the analysis software of collaborators around the globe, Summers has been instrumental.
“The JWST images far exceed what we expected from my simulations prior to the first science observations,” Summers said. “Analyzing these JWST images, I was most surprised by their exquisite resolution.”
Jansen’s primary interest is to figure out how galaxies like our own Milky Way came to be. And the way to do that is by looking far back in time at how galaxies came together, seeing how they evolved, effectively, and so tracing the path from the Big Bang to people like us.
"I was blown away by the first PEARLS images," Jansen said. "Little did I know, when I selected this field near the North Ecliptic Pole, that it would yield such a treasure trove of distant galaxies, and that we would get direct clues about the processes by which galaxies assemble and grow — I can see streams, tails, shells and halos of stars in their outskirts, the leftovers of their building blocks."
Third-year astrophysics graduate student O'Brien designed algorithms to measure faint light between the galaxies and stars that first catch our eye.
"The diffuse light that I measured in between stars and galaxies has cosmological significance, encoding the history of the universe," O'Brien said. "I feel fortunate to start my career right now — JWST data is like nothing we have ever seen, and I'm excited about the opportunities and challenges it offers."
“I expect that this field will be monitored throughout the JWST mission, to reveal objects that move, vary in brightness or briefly flare up, like distant exploding supernovae or accreting gas around black holes in active galaxies,” Jansen said.
ASU press contact:
Kim Baptista, 707-479-0311, Kim.baptista@asu.edu
###
JOURNAL
The Astronomical Journal
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
JWST PEARLS. Prime Extragalactic Areas for Reionization and Lensing Science: Project Overview and First Results
ARTICLE PUBLICATION DATE
14-Dec-2022
New study confirms the light from
outside our galaxy brighter than
expected
Study led by RIT scientists uses data taken by LORRI on NASA’s New Horizons mission
Peer-Reviewed PublicationScientists analyzed new measurements showing that the light emitted by stars outside our galaxy is two to three times brighter than the light from known populations of galaxies, challenging assumptions about the number and environment of stars are in the universe. Results of the study led by researchers at Rochester Institute of Technology have been posted to ArXiv and accepted for publication in The Astrophysical Journal.
The research team analyzed hundreds of images of background light taken by the Long-Range Reconnaissance Imager (LORRI) on NASA’s New Horizons mission to calculate the cosmic optical background (COB)—the sum of light emitted by stars beyond the Milky Way over the history of the universe. If the COB brightness doesn’t equal the light from galaxies we know about, it suggests there might be missing sources of optical light in the universe.
“We see more light than we should see based on the populations of galaxies that we understand to exist and how much light we estimate they should produce,” said Teresa Symons ’22 Ph.D. (astrophysical sciences and technology), who led the study for her dissertation and is now a postdoctoral researcher at University of California Irvine. “Determining what is producing that light could change our fundamental understanding of how the universe formed over time.”
Earlier this year, an independent team of scientists reported the COB was twice as large as originally believed in Astrophysical Journal Letters. Those results were no fluke, as corroborated using a much broader set of LORRI observations in the new study by Symons, RIT Associate Professor Michael Zemcov, and researchers at the Jet Propulsion Laboratory at Caltech, UC Irvine, UC Berkeley, and Johns Hopkins University.
While an unobscured measurement of the COB is difficult to achieve from the Earth due to dust between planets, the New Horizons spacecraft is at the edge of our solar system where this foreground is minimal and provides a much clearer view for this type of study. The scientists hope that future missions and instruments can be developed to help explore the discrepancy.
“This has gotten to the point where it’s an actual mystery that needs to be solved,” said Zemcov, a research professor at RIT’s Center for Detectors and School of Physics and Astronomy. “I hope that some of the experiments we’re involved in here at RIT including CIBER-2 and SPHEREx can help us resolve the discrepancy.”
To learn more, read the full study on the ArXiv website.
JOURNAL
The Astrophysical Journal
ARTICLE TITLE
A Measurement of the Cosmic Optical Background and Diffuse Galactic Light Scaling from the R < 50 AU New Horizons-LORRI Data
Astronomers discover clues about stellar ‘glitching’
New evidence shows that many stars experience irregularities in their core
COLUMBUS, Ohio – Astronomers have found a way to peer into the physics of some of the brightest stars in the sky.
Using data from NASA’s Kepler space telescope, an international team of researchers has found new evidence that red giants, dying stars that have exhausted their supply of hydrogen and are in the final stages of stellar evolution, often experience large-scale structural variations, or what are known as “glitches” deep inside their inner core.
The stellar glitches popularized in the media have to do with a star’s rotation, but lead author Mathieu Vrard studies a different kind of defect. The glitches in this study can affect a star’s oscillations, or the frequencies and paths that sound waves travel when passing through a star.
Red clump stars, helium-core burning objects, are often used in astrophysical studies as probes of distance to measure aspects like galaxy density, and to learn more about the physical processes behind stellar chemical evolution. So it’s vital that scientists understand why these discontinuities happen, said Vrard, a postdoctoral research associate in astronomy at the Ohio State University.
“By analyzing these variations, we can use them to obtain not only the global parameters of the star, but also information on the precise structure of those objects,” he said.
The study, recently published in the journal Nature Communications is the first to perform detailed observational characterizations on the deepest layers of these red giants.
In order to determine if these glitches were becoming more prevalent across certain star groups, the team selected a sample of 359 red giants that were below a certain stellar mass, and measured various properties and individual frequencies of each star.
The team found proof that 24 of the red giants surveyed (about 7% of those in the sample) had experienced intermittent structural discontinuities at one point or another during their lifetime. While 7% may not seem like much, if applied to all of the known stars in our universe, the number of stars that have these irregularities would be enormous.
There are two main theories that explain how these disturbances might work. The first scenario posits that glitches are present throughout the star’s evolution, but are generally very weak and below the threshold for what astronomers would categorize as a true discontinuity.
The second suggests that irregularities are “smoothed out” by some unknown physical process that later leads to changes in the structure of the star’s core.
As it turns out, the first scenario is not supported by this study’s model, which predicts that glitches observed are actually a common occurrence, but more precise data is needed before scientists can confidently subscribe to the second.
“What we think is that the second theory might hold up better because the first one didn't make sense with our observations,” Vrard said.
As the study offers a better characterization of the physical processes taking place inside red-giant stars, Vrard’s work could potentially have large implications for the field of asteroseismology – a branch of astronomy that studies the internal composition of stars using the oscillations of sound waves – and for galactic archaeology, a field that uses detailed stellar fossil records to uncover the history of the universe.
And though Vrard’s current analysis has come to an end, he aims to build on the scientific community’s knowledge of red-giant stars by examining more precise data that could help cultivate even more refined stellar models.
This work received support from NASA as well as the European Regional Development Fund.
#
Contact: Mathieu Vrard, Vrard.1@osu.edu
Written by: Tatyana Woodall, Woodall.52@osu.edu
JOURNAL
Nature Communications
METHOD OF RESEARCH
Meta-analysis
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Evidence of structural discontinuities in the inner core of red-giant stars
ARTICLE PUBLICATION DATE
16-Dec-2022
Astronomers may have uncovered
how galaxies change their shape
Researchers may have answered a decades-old question about galaxy evolution, leveraging the power of artificial intelligence (AI) to accelerate their research.
Researchers may have answered a decades-old question about galaxy evolution, leveraging the power of artificial intelligence (AI) to accelerate their research.
Ever since the Hubble Sequence, that classifies galaxy morphologies, was invented in 1926, astronomers have been refining our understanding of galaxy evolution and morphology as our technology advances.
By the 1970’s, researchers had confirmed that lone galaxies tend to be spiral-shaped, and those found in clusters of galaxies were likely to be smooth and featureless, known as elliptical and lenticular (shaped like a lens).
Published today in the journal Monthly Notices of the Royal Astronomical Society, new research led by astronomers at the International Centre for Radio Astronomy Research (ICRAR) may have uncovered the reason for these differences in shapes.
Lead author Dr Joel Pfeffer from The University of Western Australia node of ICRAR, said the research explains the ‘morphology-density relation’ – where clustered galaxies appear smoother and more featureless than their solo counterparts.
“We’ve discovered there are a few different things going on when we get lots of galaxies packed together,” Dr Pfeffer said.
“The spiral arms on galaxies are so fragile, and as you go to higher densities in the galaxy clusters, spiral galaxies start to lose their gas.
“This loss of gas causes them to ‘drop’ their spiral arms, transforming into a lenticular shape.”
“Another cause is galaxy mergers, which can see two or more spiral galaxies crashing together to form one large elliptical galaxy in the aftermath.”
The study utilised the powerful EAGLE simulations to analyse a group of galaxies in detail, using an AI algorithm to classify galaxies by their shape.
The neural network-based algorithm was trained by ICRAR PhD candidate Mitchell Cavanagh and can classify almost 20,000 galaxies per minute, compressing what would typically take weeks into one hour.
The simulations closely match what has been observed in the Universe, giving researchers the confidence to use the simulation results to interpret observations of galaxy clusters
The study also identified several lenticular galaxies outside of the high-density regions where they are expected, with the modelling suggesting they were created by the merging of two galaxies.
Dr Pfeffer said the work brings together various pieces of research in galactic evolution, to understand the morphology-density relation for the first time.
“There's been lots of suggestions over time,” he said. “But this is the first work to really put all of pieces of the puzzle together.”
PUBLICATION:
https://academic.oup.com/mnras/article/518/4/5260/6891783
‘The galaxy morphology-density relation in the EAGLE simulation, published in Monthly Notices of the Royal Astronomical Society on December 16, 2022.’
MORE INFO:
ICRAR
The International Centre for Radio Astronomy Research (ICRAR) is a joint venture between Curtin University and The University of Western Australia with support and funding from the State Government of Western Australia.
The EAGLE simulation
EAGLE (Evolution and Assembly of GaLaxies and their Environments) is a simulation aimed at understanding how galaxies form and evolve. This simulation is one of the largest cosmological hydrodynamical simulations ever, using nearly 7 billion particles to model the physics. It took more than one and a half months of computer time on 4000 compute cores of the DiRAC-2 supercomputer in Durham.
MULTIMEDIA:
Images are available from www.icrar.org/eagle-morphology-density
JOURNAL
Monthly Notices of the Royal Astronomical Society
METHOD OF RESEARCH
Computational simulation/modeling
ARTICLE TITLE
The galaxy morphology-density relation in the EAGLE simulation
ARTICLE PUBLICATION DATE
16-Dec-2022