ESA's Euclid celebrates first science with sparkling cosmic views

This image of the spiral galaxy NGC 6744 is released as part of the Early Release Observations from ESA’s Euclid space mission. It’s a typical example of the type of galaxy currently forming most of the stars in the nearby Universe, making it a wonderful archetype to study with Euclid. © 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.

In this image the faint diffuse emission around the center of the Perseus galaxy cluster has been highlighted in black and white. Even though this ‘intra-cluster light’ is much fainter than the bright cluster galaxies it contributes 20% to the overall luminosity. © Euclid consortium, MPE

Some dwarf galaxies survive the strong tidal forces in the Perseus galaxy cluster, shown here as zoom-ins. In total, the Euclid researchers found 1100 dwarf galaxies, many are much fainter than ever seen before in the Perseus galaxy cluster. © Euclid consortium, LMU, MPE

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Analysis of the early release observations provides insights into the evolution of the Perseus galaxy cluster

Today, ESA’s Euclid space mission releases five unprecedented new views of the Universe. The never-before-seen images demonstrate Euclid’s ability to unravel the secrets of the cosmos and enable scientists to hunt for rogue planets, use lensed galaxies to study mysterious matter, and explore the evolution of the Universe. The new images accompany the mission’s first scientific data, also made public today, and several science papers, including one led by the Max Planck Institute for Extraterrestrial Physics in Garching, with an unprecedented analysis of the faint intra-cluster light of the Perseus cluster of galaxies.

The full set of Euclid’s early observations targeted 17 astronomical objects, from nearby clouds of gas and dust to distant clusters of galaxies, ahead of Euclid’s main survey. Euclid will 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.

While visually stunning, the images are far more than beautiful snapshots; they reveal new physical properties of the Universe thanks to Euclid’s novel and unique observing capabilities. These scientific secrets are detailed further in a number of accompanying papers released by the Euclid collaboration, together with five key reference papers about the Euclid mission (see link to the ESA press release on the left). Euclid produced this early catalogue in just a single day, revealing over 11 million objects in visible light and 5 million more in infrared light.

Euclid’s image of the Perseus cluster of galaxies was published as one of the first images of the space telescope, just six months ago. Perseus is one of the most spectacular objects in our cosmic neighborhood: It is located at a distance of “only” 240 million light years (at a redshift of z = 0.018) and is the brightest X-ray cluster. With its high total mass of 650 trillion solar masses, its gravity ties thousands of galaxies together.

For the first time, a team led by the Max Planck Institute for Extraterrestrial Physics (MPE) has now been able to analyze the diffuse light from the Perseus galaxy cluster to far-out regions. “The high sensitivity at optical and near-infrared wavelengths over a huge field of view allows us to capture the extended faint light in the Perseus cluster,” says Matthias Kluge, lead author of the study, which is now being published together with 14 other papers. “This light is more than 100,000 times fainter in the infrared than the darkest night sky on Earth. Nevertheless, due to its large volume, it accounts for about 20% of the luminosity of the entire cluster.”

In addition, the team also used Euclid's excellent visible light imaging capabilities - comparable to the Hubble Space Telescope - to detect 50,000 free-flying globular clusters. The characteristics of the globular clusters and the bluish color of the diffuse light indicate their common origin: On the one hand, they originate from the low-metallicity outer regions of massive cluster galaxies that have been stripped away by the tidal forces of the cluster. On the other hand, there is an increasing contribution of dwarf galaxies, which were also completely torn apart by the strong tidal forces, with increasing distance from the cluster center.

In a further study, numerous surviving dwarf galaxies were detected in the Perseus cluster. Raphael Zöller from MPE and LMU was significantly involved in the measurements: “Euclid is located at the second Lagrange point far outside the Earth's atmosphere. Thanks to the dark image background, the excellent image resolution and the large field of view, we were able to detect 1100 dwarf galaxies, including hundreds with much fainter luminosity than ever before in the Perseus galaxy cluster.”

Background information

Euclid is a space mission of the European Space Agency (ESA) with contributions from the National Aeronautics and Space Administration (NASA). It is the second M-class mission in ESA's Cosmic Vision programme.

VIS and NISP were developed and built by a consortium of scientists and engineers from 17 countries, many from Europe, but also from the USA, Canada and Japan. From Germany, the Max Planck Institute for Astronomy (MPIA) in Heidelberg, the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, the Ludwig Maximilian University (LMU) in Munich, the University of Bonn (UB), the Ruhr University Bochum (RUB) and the German Space Agency at the German Aerospace Centre (DLR) in Bonn are participating. As partner of the Euclid project, MPE is responsible for the optical components of the NISP instrument as well as for the optical design and modelling of the image quality and is hosting one of Euclid's nine Science Data Centers.

The German Space Agency at DLR coordinates the German ESA contributions and also provides funding of 60 million euros from the National Space Programme for the participating German research institutes.

With around 21%, Germany is the largest contributor to the ESA science programme.

Source: Max Planck Institute for Extraterrestrial Physics (MPE)

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Contacts:

Matthias Kluge
postdoc
tel:+49 89 30000-3576
fax:+49 89 30000-
mkluge@mpe.mpg.de

Raphael Zöller
phd student
fax:+49 89-
rzoeller@mpe.mpg.de

Ralf Bender
director
tel:+49 89 30000-3702
fax:+49 89 30000-3351
bender@mpe.mpg.de

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Original publications with main contributions from authors at MPE

(public on 24.05.2024)

1. M. Kluge et al.
Euclid: Early Release Observations – The intracluster light and intracluster globular clusters of the Perseus cluster
submitted

Source

2. Marleau et al.
Euclid: Early Release Observations – Dwarf galaxies in the Perseus galaxy cluster
submitted

Source

3. Cuillandre et al.
Euclid: Early Release Observations – Programme overview and pipeline for compact- and diffuse-emission photometry
submitted

Source

4. Cuillandre et al.

Euclid: Early Release Observations – Overview of the Perseus cluster and analysis of its luminosity & stellar mass functions submitted

Source:

5. Atek et al.
Euclid: Early Release Observations – A preview of the Euclid era through a magnifying lens
submitted

Source

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More Information

Euclid @ MPE

Information on Euclid at ESA

ESA's Euclid celebrates first science with sparkling cosmic views

ESA Press Release with further images, information and Iinks

LMU Press Release

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Planet and Star Formation

We study the formation of stars on all scales and the birth of planetary systems and their evolution. The Department established observational programs to search for extrasolar planets and to characterize their properties. We investigate the chemical and physical state of the interstellar medium and protoplanetary disks in dedicated laboratory experiments where we study the formation of complex organic molecules and cosmic dust analogues.

Star formation is a key process in the universe, shaping the structure of entire galaxies and driving their chemical evolution and, at the same time, providing the conditions for the formation of planets. Our goal is to understand the different modes of star formation, from massive star clusters to more isolated groups of low-mass stars.

We want to unravel the mysteries of planet formation from tiny dust grains to the formation of giant planets and their migration in gas disks. At the same time, we establish new search strategies for brown dwarfs and exoplanets and are beginning to characterize their atmospheres.

To this end, we combine multi-wavelength observations from large ground-based telescopes and space-born infrared observatories with large-scale numerical simulations on supercomputers, theoretical models, and dedicated laboratory experiments. Our research places extreme demands on observational techniques, pushing available angular resolution, dynamic range, and spectral resolving power to their limits. We help develop and construct astronomical instruments to meet these demanding requirements. Our particular fields of expertise are adaptive optics and interferometry for ground-based observations, and sensitive space-based infrared instruments.

Source: Max Planck Institute for Astronomy

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Heidelberg Initiative for the Origins of Life – HIFOL

The Heidelberg Initiative for the Origins of Life (HIFOL) seeks to understand one of the most fundamental questions of humanity: how did life emerge on Earth and does life exist elsewhere in the Universe. HIFOL facilitates a wide range of interdisciplinary theoretical, experimental, and observational research covering the fields of astronomy, physics, geosciences, chemistry, biology and life sciences from a range of research institutes based in Heidelberg. HIFOL brings together researchers from the Max Planck Institute for Astronomy, the Max Planck Institute for Nuclear Physics, the University of Heidelberg, Heidelberg Institute of Theoretical Studies, and Kirchhoff Institute for Physics, each tackling different aspects of the same problem.

Astrophysicists aim to understand how planets form around stars and search for habitable Earth analogues, characterizing their atmospheres, using both space- and ground-based telescopes. Using both meteoritic and earth samples, geoscientists strive to unravel the past evolutionary history of the solar system and earth itself, including its interior, crust and hydrosphere. Chemists focus on studying the conditions at which amino acids, nucleotides and their first chains could be abiogenically synthesized and started the self-catalytic replication cycle, while biologists seek to figure out how transition from a non-living to a living world has occurred and where on early Earth it has happened, and how first cells, their membranes, metabolic and reproduction systems have emerged.

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Contact:

Dr. Myriam Benisty
Director
benisty@mpia.de

Office:

Christelle Hiemstra
Assistant to the Managing Director
tel:06221/528-436
hiemstra@mpia.de

Director Emeritus:

Prof. Dr. Dr. h.c. Thomas K. Henning
tel:+49 6221 528-200
henning@mpia.de

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Sloshing cold front detected in a massive galaxy cluster

RGB (tricolor) image of Abell 2566 obtained by proper combination of emission measured at 1.4 GHz with VLA

By analyzing the data from NASA's Chandra X-ray observatory, astronomers from India and South Africa have investigated a massive galaxy cluster known as Abell 2566. They detected sloshing cold fronts in the intracluster medium (ICM) of this cluster. The finding was reported in a research paper published May 17 on the preprint server arXiv.

Galaxy clusters contain up to thousands of galaxies bound together by gravity. They are the largest known gravitationally bound structures in the universe, and could serve as excellent laboratories for studying galaxy evolution and cosmology.

In general, the so-called cold fronts are sharp surface brightness discontinuities observed in X-ray images, where the drop of the surface brightness and gas density is accompanied by a jump in the gas temperature, with the denser region colder than the more rarefied region.

Now, a team of astronomers led by Sonali K. Kadam of the Swami Ramanand Teerth Marathwada University in India has identified such features in Abell 2566—a cool core galaxy cluster at a redshift of 0.08, with an estimated mass of about 217 trillion solar masses.

By analyzing Chandra images and archival radio data, Kadam's team found evidence of gas sloshing in the core of Abell 2566 along with a pair of cold fronts in its environment.

First of all, the collected images unveiled an unusual morphology of ICM distribution—in the form of spiral-shaped gas sloshing along with edges in the surface brightness distribution. Spectral analysis conducted by the astronomers then confirmed an association of these morphological discontinuities with the cold fronts.

"A detailed analysis of the sectorial brightness profiles along these edges confirm their origin due to sloshing of gas, referred to as the sloshing cold fronts," the researchers explained.

Furthermore, the observations identified an offset of about 22,200 light years between the brightest cluster galaxy (BCG) and the X-ray emission peak, as well as close association of the BCG with a neighboring system. The authors of the paper suppose that this offset might have yielded the sloshing structure in Abell 2566.

Based on the collected data, the astronomers assume that the observed features and complex morphology of plasma distribution in Abell 2566 share a common origin—as they may be due to a minor merger. The team noted that a sub-cluster may have disturbed the main cluster by displacing its gravitational potential well.

"Such a displacement further results in the formation of cold fronts, the concentrically shaped borders in the surface brightness produced by the core's gas as it moves around the potential well. These cold fronts further develop spiral patterns in the plasma distribution provided the sloshing direction is close to the plane of sky," the scientists concluded.

by Tomasz Nowakowski, Phys.org

Source: Phys.Org/Astronomy & Space

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More information: S. K. Kadam et al, Sloshing Cold Fronts in Galaxy Cluster Abell 2566, arXiv (2024). DOI: 10.48550/arxiv.2405.10475

Journal information: arXiv

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© 2024 Science X Network

Explore further

Two large cold fronts detected in the galaxy cluster Abell 3558

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To Inspiral or Not to Inspiral

Illustration of the exoplanet WASP-12 b
Credit:NASA/JPL-Caltech

 

Title: Doomed Worlds I: No New Evidence for Orbital Decay in a Long-Term Survey of 43 Ultra-Hot Jupiters
Authors: Elisabeth R. Adams et al.
First Author’s Institution: Planetary Science Institute
Status: Accepted to PSJ

Ultra-hot Jupiters: Fleeting Beauties?

Ultra-hot Jupiters are gas giants orbiting close to their stars, with orbital periods less than roughly three days. Because these planets are large and close to their stars, they produce large signals, making them promising targets for detection and characterization. But, you know what they say: all good things must come to an end. These planets are expected to experience large tidal effects from their stars, resulting in a loss of angular momentum, orbital decay, and, eventually, the star engulfing the planet.

Several lines of evidence support the picture that ultra-hot Jupiters are subject to orbital decay over long timescales. For instance, stars hosting hot Jupiters tend to be younger than the average exoplanet host star, and ultra-hot Jupiters are rarer around older host stars. A recent research article even reports a direct detection of a planetary engulfment event from the sudden, short-lived increase in brightness of a faint star. While this evidence paints a compelling picture, it is difficult to estimate how quickly we expect ultra-hot Jupiters to experience orbital decay given theoretical uncertainty in stellar tidal effects.

Keeping Time: Working Hard or Hardly Working?

Because we expect orbital decay to occur and we know of thousands of transiting exoplanets, some of which have been observed for decades, several teams have searched for orbital decay and found two promising detections: WASP-12 b and Kepler-1658 b. Searching for orbital decay relies on the detection of transit-timing variations. This is when a planet passes in front of its star along our line of sight earlier or later than expected. There are many sources of transit-timing variations in addition to orbital decay, including precession, perturbations from companion planets or stars, or acceleration of the host star toward Earth.

Let’s say we observe the transit of a planet at time t = 0 and know its period, P. We expect to observe transits at time P, 2P, 3P, etc. In the case of orbital decay, the period of the planet is getting shorter as time goes on, meaning we need to factor in an additional quadratic term encoding the rate at which the period shrinks. Then, to detect a statistically significant signal of orbital decay, we need to show that the quadratic model fits the data better than the constant-period linear model. The authors of today’s article attempt to do exactly this but with an impressive level of care and attention to detail.

This science depends upon accurate and precise measurements of transit times for each planet in the authors’ sample, most of which have been observed by several teams with various instruments and methodologies over years or decades. Moreover, each transit time must be reported in one unified timing system (click here for more info on one of the most common timing systems). Not every transit observation properly identifies its timing system or accurately converts between timing systems, meaning any historical inaccuracies complicate such studies.

Statistical Methods: Comparing Models

The authors of today’s article compile transit times for 43 ultra-hot Jupiters and take new transit data for six of those planets to extend the temporal baseline of observations. To assess whether the linear (constant period) or quadratic (changing period) model fits the data better, the authors use the Bayesian information criterion (BIC), a model selection criterion that awards a good fit but penalizes additional parameters to avoid overfitting. The authors calculate the difference in the BIC (ΔBIC) between the linear and quadratic models, with a larger ΔBIC suggesting the quadratic model is preferred.

The authors additionally perform a variety of steps to ensure the quality of the data. They perform omit-one tests, where individual transit times are removed from the analysis and flagged if they alter the ΔBIC result by more than 25%. This step is essential since one transit time recorded inaccurately or in the wrong system could result in a spurious detection of orbital decay. The authors additionally perform a “rescaling test,” where the error bars are scaled up to account for unrealistically small error bars in reported transit times.

Results

As shown in Figure 1, four planets out of the sample of 43 had a ΔBIC above the detection threshold, including WASP-12 b, which had been found previously to show orbital decay. The authors measure WASP-12 b’s period to be shrinking by 30 milliseconds per year, matching previously reported values. The planets WASP-121 b and WASP-46 b show tentative period increases, but these results are highly dependent on one or a few data points, warranting further observations. The planet TrES-1 b has prior tentative claims of its period decreasing, and the authors find a tentative period decrease of 18 milliseconds per year. However, this rate of period shrinkage suggests stellar tidal effects that would differ greatly from theoretical predictions, perhaps suggesting a cause of period decrease other than orbital decay.

Figure 1: The value of each planet’s ΔBIC shown relative to a threshold of ΔBIC = 30 (top), zoomed in results (middle), and rescaled results (bottom) with scaled up uncertainties, indicating only WASP-12 b definitively shows signs of orbital decay. Credit: Adams et al. 2024

Only one planet, WASP-12 b, was found to have a clear period decrease after rescaling error bars, as shown in the bottom panel of Figure 1. The authors predict that if the orbits of the other planets in the sample were decaying as rapidly as the orbit of WASP-12 b, they could have found significant detections of period decrease in roughly half the sample. There is thus no evidence that orbital decay is common among ultra-hot Jupiters, which is possibly confounding considering the other lines of evidence that suggest ultra-hot Jupiters are subject to decay. Though patience is required, as time goes on, it will be possible to search for orbital decay around more planets at higher precision, helping us ascertain the ultimate fate of close-in planets.

Original astrobite edited by Ivey Davis.

Source: American Astronomical Society (AAS-Nova)

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About the author, Kylee Carden:

I am a first-year PhD student at The Ohio State University, where I am an observer of planets outside the solar system. I’m involved with the transiting exoplanet survey of the upcoming Roman Space Telescope and working with high-resolution spectroscopic observations of exoplanet atmospheres. I am a huge fan of my cat Piccadilly, cycling, and visiting underappreciated tourist sites.

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Editor’s Note: Astrobites is a graduate-student-run organization that digests astrophysical literature for undergraduate students. As part of the partnership between the AAS and astrobites, we occasionally repost astrobites content here at AAS Nova. We hope you enjoy this post from astrobites; the original can be viewed at astrobites.org.

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The lights of a galactic bar

NGC 4731

A close-in view of a barred spiral galaxy. The bright, glowing bar crosses the centre of the galaxy, with spiral arms curving away from its ends and continuing out of view. It’s surrounded by bright patches of light where stars are forming, as well as dark lines of dust. The galaxy’s clouds of gas spread out from the arms and bar, giving way to a dark background with some foreground stars and small, distant galaxies. Credit: ESA/Hubble & NASA, D. Thilker

This week, an image of the broad and sweeping spiral galaxy NGC 4731 is the Hubble Picture of the Week. This galaxy lies among the galaxies of the Virgo cluster, in the constellation Virgo, and is located 43 million light-years from Earth. This highly detailed image was created using six different filters. The abundance of colour illustrates the galaxy's billowing clouds of gas, dark dust bands, bright pink star-forming regions and, most obviously, the long, glowing bar with trailing arms.

Barred spiral galaxies outnumber both regular spirals and elliptical galaxies put together, numbering around 60% of all galaxies. The visible bar structure is a result of orbits of stars and gas in the galaxy lining up, forming a dense region that individual stars move in and out of over time. This is the same process that maintains a galaxy's spiral arms, but it is somewhat more mysterious for bars: spiral galaxies seem to form bars in their centres as they mature, accounting for the large number of bars we see today, but can also lose them later on as the accumulated mass along the bar grows unstable. The orbital patterns and the gravitational interactions within a galaxy that sustain the bar also transport matter and energy into it, fuelling star formation. Indeed, the observing programme studying NGC 4731 seeks to investigate this flow of matter in galaxies.

Beyond the bar, the spiral arms of NGC 4731 stretch out far past the confines of this close-in Hubble view. The galaxy’s elongated arms are thought to result from gravitational interactions with other, nearby galaxies in the Virgo cluster.

Source: ESA/Hubble/potw

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New Catalog Showcases a Diverse Exoplanet Landscape with Strange, Exotic Worlds

Artist’s rendition of the 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. Credit: W. M. Keck Observatory/Adam Makarenko

NASA TESS-Keck Survey is the single largest uniform analysis of TESS planets to date

A new, robust catalog is out featuring 126 confirmed and candidate exoplanets discovered with the National Aeronautics and Space Administration (NASA) Transiting Exoplanet Survey Satellite (TESS) in collaboration with W. M. Keck Observatory on Maunakea, Hawaiʻi.

In this latest installment of the TESS-Keck Survey, the catalog consists of thousands of radial velocity (RV) observations that 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 study is published in today’s edition of The Astrophysical Journal Supplement.

“The results that have come from the TESS-Keck Survey represents the single largest contribution to understanding the physical nature and system architectures of new planets TESS has discovered,” says University of Kansas Physics and Astronomy graduate student Alex Polanski, the lead author of the paper. “Catalogs like this help astronomers place individual worlds in context with the rest of the exoplanet population.”

Polanski and a global team of astronomers from multiple institutions spent three years developing the catalog; they took TESS planetary data and analyzed 9,204 RV measurements, 4,943 of which were taken over the course of 301 observing nights using Keck Observatory’s planet-hunting instrument called the High-Resolution Echelle Spectrometer (HIRES).

“The TESS-Keck Survey results fundamentally depend on Doppler spectroscopy from Keck Observatory’s HIRES. The U.S. science community has relied on this workhorse instrument for exoplanet studies for nearly three decades,” says University of Kansas Associate Professor of Physics and Astronomy Ian Crossfield, a co-author of the paper.

The team also obtained an additional 4,261 RV with The University of California Observatories’ Automated Planet Finder at Lick Observatory in California. With the combined total of RV measurements, they were able to calculate the masses of 120 confirmed planets plus six candidate planets.

“RV measurements let astronomers detect, and learn the properties of, these exoplanetary systems. When we see a star wobbling regularly back and forth, we can infer the presence of an orbiting planet and measure the planet’s mass,” says Crossfield.

The wobble produces a regular change in wavelengths due to the Doppler effect, which is detected through the RV method — one of the techniques used to find exoplanets. The phenomenon refers to the gravitational effect an exoplanet has on its host star, where it tugs the star as the planet orbits around it. When the host star moves toward a telescope, its visible light turns slightly bluer; when it moves away from us, the light shifts slightly redder. This is much like how sound behaves; a fire truck’s siren gets higher-pitched as it travels closer to you, and sounds lower-pitched as it drives farther away.

Of the planets profiled in the TESS-Keck Survey, two planets — TOI-1824 b and TOI-1798 c — stand out as examples of worlds that have such peculiar characteristics they give new insight into exoplanet classification and serve as potential touchstones for deepening astronomers’ understanding of the diverse ways planets form and evolve.

TOI-1824 b: A Superdense Sub-Neptune

One of the densest sub-Neptunes in the TESS-Keck Survey catalog, and the subject of another TESS-Keck Survey paper by University of California (UC), Santa Cruz undergraduate Sarah Lange, TOI-1824 b is unusually dense for a planet its size.

“At nearly 19 times the mass of Earth, but only 2.6 times the size of our home planet, TOI-1824 b is an exoplanet oddity,” says co-author Joseph Murphy, a graduate student at the UC Santa Cruz. “Planets similar in size typically have a mass between roughly 6 and 12 times the mass of Earth.”

One explanation for why TOI-1824 b is so massive yet appears much smaller than usual is it could have an Earth-like core surrounded by an unusually thin, hydrogen-dominated atmosphere. Another possibility is the planet has a water-rich core beneath a steam atmosphere.

“This superdense sub-Neptune may be the massive cousin of water worlds, which are small planets with high H₂O content purported to exist around red dwarf stars,” says Murphy.

Red dwarfs, or M dwarf stars, are the most common star type in the Milky Way galaxy. They make ideal targets in the search for habitable worlds because M dwarfs are cooler than the Sun; this allows for liquid water to exist on planets orbiting closer to them, therefore making these systems easier to study.

TOI-1798 c: A rare, extreme Super-Earth

TOI-1798 is an orange dwarf, or K-type star, with two planets: TOI-1798 b, a sub-Neptune that has an orbit of about eight days, and TOI-1798 c, a super-Earth that is so close to its host star, it completes one orbit in less than 12 hours. This rare planetary system is one of only a few star systems known to have an inner planet with an ultra-short period (USP) orbit.

“While the majority of planets we know about today orbit their star faster than Mercury orbits the Sun, USPs take this to the extreme. TOI-1798 c orbits its star so quickly that one year on this planet lasts less than half a day on Earth. Because of their proximity to their host star, USPs are also ultra hot — receiving more than 3,000 times the radiation that Earth receives from the Sun. Existing in this extreme environment means that this planet has likely lost any atmosphere that it initially formed,” says Polanski.

With the TESS-Keck Survey’s Mass Catalog, astronomers now have a new database to explore the latest research on worlds that TESS has detected; this paves the way for studying the variables and conditions of their environments in finer detail, particularly ones that could harbor life as we know it.

“There are still thousands of unconfirmed planets from the TESS mission alone, so large releases of new planets like this will become more common as astronomers work to get a handle on the diversity of worlds we see today,” says Crossfield.

Source: W. M. Keck Observatory

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Companion Papers

Subgiants Catalog: “The TESS-Keck Survey XXI: 13 New Planets and Homogeneous Properties for 21 Subgiant Systems” (Ashley Chontos et al.)

Individual Systems:

• TOI-1347: “The TESS-Keck Survey. XII. A Dense 1.8 R⊕ Ultra-Short-Period Planet Possibly Clinging to a High-Mean-Molecular-Weight Atmosphere After the First Gyr,” The Astronomical Journal, March 2024  (Ryan Rubenzahl et al.)
• TOI-1386: “The TESS-Keck Survey. XIX. A Warm Transiting Sub-Saturn Mass Planet and a non-Transiting Saturn Mass Planet Orbiting a Solar Analog,” The Astronomical Journal, March 2024 (Michelle Hill et al.)
• TOI-1437: “The TESS-Keck Survey XXII. A sub-Neptune Orbiting TOI-1437” (Daria Pidhorodetska et al.)
• TOI-1751: “The TESS-Keck Survey. XVIII. A sub-Neptune and spurious long-period signal in the TOI-1751 system,” The Astronomical Journal, April 2024 (Anmol Desai et al.)
• TOI-1824: “The TESS-Keck Survey. VII. A Superdense Sub-Neptune Orbiting TOI-1824” (Sarah Lange et al.)

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About HIRES

The High-Resolution Echelle Spectrometer (HIRES) produces spectra of single objects at very high spectral resolution, yet covering a wide wavelength range. It does this by separating the light into many “stripes” of spectra stacked across a mosaic of three large CCD detectors. HIRES is famous for finding exoplanets. Astronomers also use HIRES to study important astrophysical phenomena like distant galaxies and quasars, and find cosmological clues about the structure of the early universe, just after the Big Bang.

About W. M. Keck Observatory

The W. M. Keck Observatory telescopes are among the most scientifically productive on Earth. The two 10-meter optical/infrared telescopes atop Maunakea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometers, and world-leading laser guide star adaptive optics systems. Some of the data presented herein were obtained at Keck Observatory, which is a private 501(c) 3 non-profit organization operated as a scientific partnership among the California Institute of Technology, The University of California Observatories, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the Native Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.

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Discovery of an Exo-Venus: a Key to Find Extraterrestrial Life

Figure 1: Artist’s conception of the newly discovered planet Gliese 12 b, which is orbiting a red dwarf star located 40 light-years away. This artist's conception assumes that the planet retains a tenuous atmosphere. Future follow-up observations will clarify what kind of atmosphere the planet actually retains. A high resolution image is here (1.9 MB). Credit: NASA/JPL-Caltech/R. Hurt (Caltech-IPAC)

An international team led by scientists from the Astrobiology Center in Japan, the University of Tokyo, the National Astronomical Observatory of Japan, and Tokyo Institute of Technology has successfully discovered a new extrasolar planet named Gliese 12 b through a collaboration between NASA's TESS campaign and a strategic survey program (SSP) of the Subaru Telescope. Gliese 12 b has a size similar to Earth and Venus, and is orbiting around its host star, Gliese 12, with a period of 12.8 days. Despite its close proximity to its host star, the amount of radiation Gliese 12 b receives is comparable to that of Venus, because the host star is much cooler than the Sun. The planet may still retain a certain amount of atmosphere, making it one of the most suitable targets out of all of the planets discovered so far to investigate the atmosphere of a planet like Venus. It remains an open question why the surface environment of Venus – a sibling of Earth – became so harsh for life compared to that of Earth. In the near future, NASA's JWST and extremely large telescopes, such as TMT, will be used to characterize the atmosphere of Gliese 12 b in detail, greatly improving our understanding of the conditions necessary for habitability.

Is Earth a special planet with its wide variety of life? Or are planets bearing life common in this Universe? In order to answer these fundamental questions, we need to look for clues from other planets that are similar to Earth. In particular, Venus in the Solar System is an important target. Venus's size and mass are very similar to those of Earth, so Venus is called "Earth's sibling." Nevertheless, its atmosphere is thick and dry and thus not like Earth's. Why did Venus develop a surface environment that is significantly different from Earth's? Although Venus's insolation – the amount of light a planet receives from the host star – is slightly higher than Earth's insolation, the answer to the above question remains unclear. Indeed, scientists don't understand why a planet develops an environment suitable for bearing life. To better understand that question, it is essential to get hints from not only Venus but also an "exo-Venus," which is a Venus-like planet outside the Solar System.

Since the 1990s, more than 5,500 planets orbiting around stars other than the Sun have been discovered by various detection methods. In particular, the Kepler satellite launched by NASA in 2009 played a major role in the discoveries and was the first to discover planets with sizes comparable to or smaller than Earth. However, as these planets are hundreds of light years away from Earth, it is challenging to characterize their atmospheres in detail with the current or even up-coming telescopes.

The current trend is to discover planets orbiting M-type stars, which are less massive than the Sun, in the vicinity of the Solar System. This is because if the star is less massive or smaller, it is easier to detect a change in the host star's velocity and brightness that originates from the orbital motion of a planet. The method to detect the velocity change is called the "Doppler" technique, while that to detect the brightness change is called the "transit" technique.

To use the Doppler technique, astronomers carry out spectroscopic observations, in which stellar light is divided into many "rainbows." A huge amount of light is required for this analysis. M-type stars are faint at visual wavelengths but bright at infrared wavelengths. So, the Subaru Telescope started a large program to search for planets via the Doppler technique in 2019 using the newly-developed infrared spectrograph, IRD. Between 2019 and 2022, the astronomers extensively monitored Gliese 12, a star located 40 light-years away in the direction of the concentration Pisces, as one of the targets of the IRD-SSP observing campaign. Gliese 12 is an M-type star one-fourth the size of the Sun, with a surface temperature of 3,000 ℃, which is 2500 ℃ cooler than the Sun.

Gliese 12, was also observed by NASA's TESS space telescope between August 2021 and October 2023. The TESS team detected signs of a planet candidate with a size similar to Earth and reported the detection in April, 2023. This report motivated the astronomers to start the follow-up observations for validating the candidate signal with the multi-color simultaneous cameras MuSCAT2 and MuSCAT3, which were developed by the Astrobiology Center (ABC) and the University of Tokyo. The analysis of the data taken with TESS and the MuSCAT series determined the orbital period of Gliese 12 b to be 12.8 days and the radius to be 0.96 Earth radii. Furthermore, the astronomers constrained the mass of Gliese 12 b to be less than 3.9 Earth masses by combining the Doppler velocity measurements taken with IRD and those with CARMENES on the Calar Alto 3.5 m telescope in southern Spain.

What kind of planet is Gliese 12 b? The orbital period of this planet, that is to say one year on this planet, is just 12.8 days. This translates to a distance between the star and the planet of only 0.07 au, where one au corresponds to the Earth–Sun distance. However, the amount of insolation Gliese 12 b receives is only 1.6 times higher than that of Earth, or similar to that of Venus (which is 1.9 times higher than Earth's), thanks to the low temperature of the host star. Nevertheless, even with such a relatively weak insolation, the planetary surface would be hot enough to start the runaway evaporation of liquid water from the surface.

Meanwhile, whether liquid water can be stably retained on the surface of a planet depends on the composition and thickness of the atmosphere. For example, even if the surface temperature of a planet is appropriate, the planet cannot retain water as a liquid on the surface if the atmosphere is too thin. However, the characteristics of the atmospheres of extrasolar planets have been poorly understood.

A well-known system for study of planetary atmospheres is the TRAPPIST-1 system, a cool M-type star with seven terrestrial planets. Among the planets around TRAPPIST-1, the second-closest planet to the star, TRAPPIST-1 c, is very similar to Gliese 12 b and Venus in size (1.1 Earth radii) and insolation (2.2 times Earth's insolation). However, recent observations by the James Webb Space Telescope (JWST) revealed that the atmosphere of TRAPPIST-1 c is at least not as thick as that of Venus. TRAPPIST-1 is active enough to release strong radiation such as X-ray and ultraviolet light, and high-energy particles like stellar winds. Most of the planet's atmosphere might have been dissipated by this high-energy radiation in the past.

In contrast, the X-ray luminosity of Gliese 12 is an order of magnitude weaker than that of TRAPPIST-1. In addition, the distance between Gliese 12 b and its host star is more than 4 times larger than that between TRAPPIST-1 c and its host. Accordingly, the effect of high-energy radiation on Gliese 12 b is much weaker than that on TRAPPIST-1 c, making it possible that Gliese 12 b might retain a certain amount of atmosphere compared with TRAPPIST-1 c.

Given that Gliese 12 is a neighbor of the Sun, Gliese 12 b is an ideal target for atmosphere characterizations with JWST and future 30-m class telescopes, alongside TRAPPIST-1. In the future, by observing the atmosphere of Gliese 12 b and comparing it with those of Venus and TRAPPIST-1 c, scientists will be able to reveal how the atmospheres of terrestrial planets vary depending on the radiation environments around the host stars.

Although Venus currently does not retain liquid water on the surface, it might have in the past. Likewise, it cannot be fully ruled out that liquid water is present on Gliese 12 b's surface. "Follow-up observations with JWST and future ground-based observations with 30-m class telescopes for transit spectroscopy are expected to determine whether Gliese 12 b has an atmosphere and whether the atmosphere contains molecular components associated with life such as water vapor, oxygen, and carbon dioxide," says Masayuki Kuzuhara, a project assistant professor of the Astrobiology Center (ABC).

There results were published in the Astrophysical Journal Letters on May 23, 2024 (Kuzuhara, Fukui et al. "Gliese 12 b: A temperate Earth-sized planet at 12pc ideal for atmospheric transmission spectroscopy").

Gliese 12 b
Credit: 4D2U project, NAOJ, NASA/JPL-Caltech/R. Hurt (Caltech-IPAC)

Source: Subaru Telescope

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About the Subaru Telescope

The Subaru Telescope is a large optical-infrared telescope operated by the National Astronomical Observatory of Japan, National Institutes of Natural Sciences with the support of the MEXT Project to Promote Large Scientific Frontiers. We are honored and grateful for the opportunity of observing the Universe from Maunakea, which has cultural, historical, and natural significance in Hawai`i.

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Relevant Links

• NAOJ May 24, 2024 Press Release
• Astrobiology Center May 23, 2024 Press Release
• W. M. Keck Observatory May 23, 2024 Press Release
• NASA May 23, 2024 Press Release

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Galaxies Actively Forming in Early Universe Caught Feeding on Cold Gas

Galaxy Forming in the Early Universe (Artist’s Concept)
Credits: Illustration: NASA, ESA, CSA, Joseph Olmsted (STScI)

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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 show 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 researchers’ findings were possible thanks to Webb’s Cosmic Evolution Early Release Science (CEERS) Survey, which includes spectra of distant galaxies from the telescope’s NIRSpec (Near-Infrared Spectrograph), and was released immediately to support discoveries like this as part of Webb’s Early Release Science (ERS) program.

This work has been published in the May 24, 2024 issue of the journal Science.

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).

Source: NASA's James Webb Space Telescope/News

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About This Release

Credits:

Media Contact:

Claire Blome
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

Permissions: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Related Links and Documents

• Era of Reionization Infographic
• How Webb Can Study the Early Universe

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Spotted — "Death Star" Black Holes in Action

Abell 478 - NGC 5044
Credit: X-ray: NASA/CXC/Univ. of Bologna/F. Ubertosi; Image Processing: NASA/CXC/SAO/N. Wolk

JPEG (122.1 kb) - Large JPEG (3.3 MB) - Tiff (70.3 MB) - More Images

A Tour of Black Hole Death Stars - More Videos

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A team of astronomers have studied 16 supermassive black holes that are firing powerful beams into space, to track where these beams, or jets, are pointing now and where they were aimed in the past, as reported in our latest press release. Using NASA’s Chandra X-ray Observatory and the U.S. National Science Foundation (NSF) National Radio Astronomical Observatory’s (NRAO) Very Large Baseline Array (VLBA), they found that some of the beams have changed directions by large amounts.

These two Chandra images show hot gas in the middle of the galaxy cluster Abell 478 (left) and the galaxy group NGC 5044 (right). The center of each image contains one of the sixteen black holes firing beams outwards. Each black hole is in the center of a galaxy embedded in the hot gas.

By mousing over the images, labels and the radio images appear. Ellipses show a pair of cavities in the hot gas for Abell 478 (left) and ellipses show two pairs of cavities for NGC 5044 (right). These cavities were carved out by the beams millions of years ago, giving the directions of the beams in the past. An X shows the location of each supermassive black hole.

Abell 478 and NGC 5044 (Labeled). Credit: X-ray: NASA/CXC/Univ. of Bologna/F. Ubertosi; Insets Radio: NSF/NRAO/VLBA; Wide field Image: Optical/IR: Univ. of Hawaii/Pan-STARRS; Image Processing: NASA/CXC/SAO/N. Wolk

The VLBA images are shown as insets, which reveal where the beams are currently pointing, as seen from Earth. The radio images are both much smaller than the X-ray images. For Abell 478 the radio image is about 3% of the width of the Chandra image and for NGC 5044 the radio image is about 4% of the Chandra image’s width.

A comparison between the Chandra and VLBA images shows that the beams for Abell 478 changed direction by about 35 degrees and the beams for NGC 5044 changed direction by about 70 degrees.

Across the entire sample the researchers found that about a third of the 16 galaxies have beams that are pointing in completely different directions than they were before. Some have changed directions by nearly 90 degrees in some cases, and over timescales between one million years and a few tens of millions of years. Given that the black holes are of the order of 10 billion years old, this represents a relatively rapid change for these galaxies.

Wide Field Views of Abell 478 [Left] and NGC 5044 [Right]. Credit: X-ray: NASA/CXC/Univ. of Bologna/F. Ubertosi et al.; Optical/IR: Univ. of Hawaii/Pan-STARRS; IR: NASA/ESA/JPL/CalTech/Herschel Space Telescope

Black holes generate beams when material falls onto them via a spinning disk of matter and some of it then gets redirected outward. The direction of the beams from each of these giant black holes, which are likely spinning, is thought to align with the rotation axis of the black hole, meaning that the beams point along a line connecting the poles.

These beams are thought to be perpendicular to the disk. If material falls towards the black holes at a different angle that is not parallel to the disk, it could affect the direction of the black hole’s rotation axes, changing the direction of the beams.

Scientists think that beams from black holes and the cavities they carve out play an important role in how many stars form in their galaxies. The beams pump energy into the hot gas in and around the galaxy, preventing it from cooling down enough to form huge numbers of new stars. If the beams change directions by large amounts, they can tamp down star formation across much larger areas of the galaxy.

The paper describing these results was published in the January 20th, 2024 issue of The Astrophysical Journal, and is available here. The authors are Francesco Ubertosi (University of Bologna in Italy), Gerritt Schellenberger (Center for Astrophysics | Harvard & Smithsonian), Ewan O’Sullivan (CfA), Jan Vrtilek (CfA), Simona Giacintucci (Naval Research Laboratory), Laurence David (CfA), William Forman (CfA), Myriam Gitti (University of Bologna), Tiziana Venturi (National Institute of Astrophysics—Institute of Radio Astronomy in Italy), Christine Jones (CfA), and Fabrizio Brighenti (University of Bologna).

NASA's Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science from Cambridge Massachusetts and flight operations from Burlington, Massachusetts.

Quick Look: Spotted: 'Death Star' Black Holes in Action

Source: NASA's Chandra X-Ray Observatory

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Visual Description:

This image contains two X-ray images presented side by side, separated by a thin, gray line. On the left is an image of galaxy cluster Abell 478, and on the right is an image of galaxy group NGC 5044.

The X-ray image of Abell 478 resembles a gooey, blue substance that has been spilled on a black canvas. Most of the image is covered in this blue goo texture, which is hot gas in X-ray light, however there are cavities where no blue texture is present. At the center of the image is a bright, white region. Within the white region, too small to identify, exists Abell 478's supermassive black hole.

The X-ray image of NGC 5044, on our right, is more pixelated than the image of Abell 478. It resembles blue television static or noise, that is present on a television when no transmission signal is detected. Most of the image is covered in this blue static, however there are cavities where no blue static is present. At the center of the image is a bright, white region. Within the white region, too small to identify, exists NGC 5044's supermassive black hole.

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Fast Facts for Abell 478:

Scale: Image is about 2 arcmin (650,000 light-years) across.
Category: Groups and Clusters of Galaxies
Coordinates (J2000): RA 4h 13m 20.7s | Dec +10° 27´ 56"
Constellation: Taurus
Observation Dates: 6 observations from Jan 27, 2001 to Jul 29, 2006
Observation Time: 27 hours 58 minutes (1 day 3 hours 58 minutes)
Obs. ID: 1669, 6102, 6928, 7231-7233
Instrument: ACIS
References: Ubertosi, F. et al, 2024, ApJ, 961, 134; arXiv:2313.02283
Color Code: X-ray: blue and white;
Distance Estimate: About 1.2 billion light-years from Earth (z=0.088)

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Fast Facts for NGC 5044:

Scale: Image is about 2.4 arcmin (87,000 light-years) across.
Category: Groups and Clusters of Galaxies
Coordinates (J2000): RA 13h 15m 23.9s | Dec -16° 23´ 07.5"
Constellation: Virgo
Observation Dates: 9 observations from Mar 3, 2000 to Aug 23, 2015
Observation Time: 156 hours 34 minutes (6 days 12 hours and 34 minutes)
Obs. ID: 798, 3225, 3664, 9399, 17195, 17196, 17653, 17654, 17666
Instrument: ACIS
References: Ubertosi, F. et al, 2024, ApJ, 961, 134; arXiv:2313.02283
Color Code: X-ray: blue and white;
Distance Estimate: About 130 million light-years from Earth (z=0.009)

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NASA's Webb Cracks Case of Inflated Exoplanet

Warm Gas-Giant Exoplanet WASP-107 b (Artist's Concept)
Credits: Artwork: NASA, ESA, CSA, Ralf Crawford (STScI)

Warm Gas-Giant Exoplanet WASP-107 b Transmission Spectrum (Hubble WFC3, Webb NIRCam, Webb MIRI)
Credits: Illustration: NASA, ESA, CSA, Ralf Crawford (STScI)
Science: Luis Welbanks (ASU), JWST MANATEE Team

Warm Gas-Giant Exoplanet WASP-107 b Transmission Spectrum (NIRSpec)
Credits: Illustration: NASA, ESA, CSA, Ralf Crawford (STScI)
Science: David Sing (JHU), NIRSpec GTO Transiting Exoplanet Team

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Why is the warm gas-giant exoplanet WASP-107 b so puffy? Two independent teams of researchers have an answer.

Data collected using NASA’s James Webb Space Telescope, combined with prior observations from NASA’s Hubble Space Telescope, show surprisingly little methane (CH₄) in the planet’s atmosphere, indicating that the interior of WASP-107 b must be significantly hotter and the core much more massive than previously estimated.

The unexpectedly high temperature is thought to be a result of tidal heating caused by the planet’s slightly non-circular orbit, and can explain how WASP-107 b can be so inflated without resorting to extreme theories of how it formed.

The results, which were made possible by Webb’s extraordinary sensitivity and accompanying ability to measure light passing through exoplanet atmospheres, may explain the puffiness of dozens of low-density exoplanets, helping solve a long-standing mystery in exoplanet science.

The Problem with WASP-107 b

At more than three-quarters the volume of Jupiter but less than one-tenth the mass, the “warm Neptune” exoplanet WASP-107 b is one of the least dense planets known. While puffy planets are not uncommon, most are hotter and more massive, and therefore easier to explain.

“Based on its radius, mass, age, and assumed internal temperature, we thought WASP-107 b had a very small, rocky core surrounded by a huge mass of hydrogen and helium,” explained Luis Welbanks from Arizona State University (ASU), lead author on a paper published today in Nature. “But it was hard to understand how such a small core could sweep up so much gas, and then stop short of growing fully into a Jupiter-mass planet.”

If WASP-107 b instead has more of its mass in the core, the atmosphere should have contracted as the planet cooled over time since it formed. Without a source of heat to re-expand the gas, the planet should be much smaller. Although WASP-107 b has an orbital distance of just 5 million miles (one-seventh the distance between Mercury and the Sun), it doesn’t receive enough energy from its star to be so inflated.

“WASP-107 b is such an interesting target for Webb because it’s significantly cooler and more Neptune-like in mass than many of the other low-density planets, the parallel study also published today in Nature. “As a result, we should be able to detect methane and other molecules that can give us information about its chemistry and internal dynamics that we can’t get from a hotter planet.”

A Wealth of Previously Undetectable Molecules

WASP-107 b’s giant radius, extended atmosphere, and edge-on orbit make it ideal for transmission spectroscopy, a method used to identify the various gases in an exoplanet atmosphere based on how they affect starlight.

Combining observations from Webb’s NIRCam (Near-Infrared Camera), Webb’s MIRI (Mid-Infrared Instrument), and Hubble’s WFC3 (Wide Field Camera 3), Welbanks’ team was able to build a broad spectrum of 0.8- to 12.2-micron light absorbed by WASP-107 b’s atmosphere. Using Webb’s NIRSpec (Near-Infrared Spectrograph), Sing’s team built an independent spectrum covering 2.7 to 5.2 microns.

The precision of the data makes it possible to not just detect, but actually measure the abundances of a wealth of molecules, including water vapor (H₂O), methane (CH₄), carbon dioxide (CO₂), carbon monoxide (CO), sulfur dioxide (SO₂), and ammonia (NH₃).

Roiling Gas, Hot Interior, and Massive Core

Both spectra show a surprisingly lack of methane in WASP-107 b’s atmosphere: one-thousandth the amount expected based on its assumed temperature.

“This is evidence that hot gas from deep in the planet must be mixing vigorously with the cooler layers higher up,” explained Sing. “Methane is unstable at high temperatures. The fact that we detected so little, even though we did detect other carbon-bearing molecules, tells us that the interior of the planet must be significantly hotter than we thought.”

A likely source of WASP-107 b’s extra internal energy is tidal heating caused by its slightly elliptical orbit. With the distance between the star and planet changing continuously over the 5.7-day orbit, the gravitational pull is also changing, stretching the planet and heating it up.

Researchers had previously proposed that tidal heating could be the cause of WASP-107 b’s puffiness, but until the Webb results were in, there was no evidence.

Once they established that the planet has enough internal heat to thoroughly churn up the atmosphere, the teams realized that the spectra could also provide a new way to estimate the size of the core.

“If we know how much energy is in the planet, and we know what proportion of the planet is heavier elements like carbon, nitrogen, oxygen, and sulfur, versus how much is hydrogen and helium, we can calculate how much mass must be in the core,” explained Daniel Thorngren from JHU.

It turns out that the core is at least twice as massive as originally estimated, which makes more sense in terms of how planets form.

All together, WASP-107 b is not as mysterious as it once appeared.

“The Webb data tells us that planets like WASP-107 b didn’t have to form in some odd way with a super small core and a huge gassy envelope,” explained Mike Line from ASU. “Instead, we can take something more like Neptune, with a lot of rock and not as much gas, just dial up the temperature, and poof it up to look the way it does.”

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).

Source: NASA's James Webb Space Telescope/News

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About This Release

Credits:

Media Contact:

Margaret W. Carruthers
Space Telescope Science Institute, Baltimore, Maryland

Christine Pulliam
Space Telescope Science Institute, Baltimore, Maryland

Science: Luis Welbanks ASU), David Sing (JHU)

Permission: Content Use Policy

Contact Us: Direct inquiries to the News Team.

Related Links and Documents

• "A high internal heat flux and large core in a warm Neptune exoplanet" by L. Welbanks, et al.
• "A warm Neptune’s methane reveals core mass and vigorous atmospheric mixing" by D. Sing, et al.
• "MIRI observation of WASP-107 b: SO2, silicate clouds, but no CH4 detected in a warm Neptune" by A. Dyrek, et al.
• ESA/Webb's Press Release
• The Johns Hopkins University Press Release
• The Arizona State University Press Release

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High School Student Creates Soundscape of Exploding Stars

A sound explosion of cosmic explosions: ZTF supernovae sonified

Vanya Agrawal creates her sonification with a computer and MIDI board.

More Videos

Vanya Agrawal discusses her experience of creating a sonification of supernova data

Agrawal's full 28-minute sonification of the ZTF supernova dataset.

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Using data from the Zwicky Transient Facility, Southern California high school student Vanya Agrawal creates new "space music."

In September 2023, Vanya Agrawal, a senior at Palos Verdes High School, was searching for a science research project. "I've been interested in music since I was very young, and, over the past few years, I've also become interested in physics and astronomy," Agrawal says. "I was planning on pursuing both as separate disciplines, but then I began to wonder if there might be a way to combine the two."

Enter data sonification. Just as researchers design graphs or diagrams or scatterplots to create a visual mapping of their data, they may also develop an audiomapping of their data by rendering it as sound. Instead of drawing a dot (or any other visual symbol) to correspond to a point of data, they record a tone.

Granted, this is highly unusual in scientific research, but it has been done. Her curiosity piqued, Agrawal soon found examples of these sonifications. For example, in 1994, an auditory researcher, Gregory Kramer, sonified a geoseismic dataset, resulting in detections of instrument error, while in 2014 the CEO and co-founder of Auralab Technologies, Robert Alexander, rendered a spectral dataset into sound and found that participants could consistently identify wave patterns simply by listening.

Do these scientific sonifications make you want to sit yourself down in a concert hall to be swept away by the music they create? Well, when you see a scatterplot of supernovae in an astrophysics journal, do you think, "What is that doing in an academic journal? It belongs on the wall of a museum!" Probably not often.

Here is where the artistic effort comes in: representing scientific information in ways that delight the eye or the ear. This was Agrawal's goal, using an astrophysical dataset to make music that could draw in nonscientific audiences and help them to engage with new discoveries about the universe.

Agrawal first approached Professor of Astronomy Mansi Kasliwal (PhD '11), a family friend, to see about finding an appropriate dataset to sonify. She was quickly put in touch with Christoffer Fremling, a staff scientist working with the Zwicky Transient Facility (ZTF) team. Using a wide-field-of-view camera on the Samuel Oschin Telescope at Caltech's Palomar Observatory, ZTF scans the entire sky visible from the Northern Hemisphere every two days, weather permitting, observing dynamic events in space.

Many of the dynamic events observed by ZTF are supernovae, the explosions of dying stars. In the dataset Agrawal received from Fremling of supernova observations from March 2018 to September 2023, there were more than 8,000 of these. She decided that each supernova detection would be one note in the music she was composing.

"I knew the things that I could modify about the music were when the note occurred, its duration, its pitch, its volume, and the instrument that played the note," Agrawal says. "Then it was a matter of looking at the parameters measured in the dataset of supernova observations and deciding which were most significant and how they should be matched up to musical features."

With Fremling's input, Agrawal decided that the five measurements associated with supernova observations that she would sonify would be discovery date, luminosity, redshift (a quantifiable change in the wavelength of light indicating the light source's distance from us), duration of explosion, and supernova type.

"Discovery date of a supernova has an obvious correlation with the time in which its associated note appears in the music," Agrawal says, "and matching the duration of a supernova with the duration of the note and the type of supernova with the type of instrument playing the note also made the most sense." As for the remaining parameters, Agrawal "flip-flopped back and forth with redshift and luminosity, which would go with pitch or volume. But I ultimately decided on having the luminosity correlate to volume because you can think of volume as the auditory equivalent to brightness. If something emits a dim light, that's like a quiet sound, but if it emits a bright light, that correlates to a loud sound. That left redshift to be translated into pitch."

Once parameters had been translated, the pitch values were modified to enhance the sound. Redshift had to be condensed into a tight range of pitches such that the result would be in the most audible range for human ears.

The initial result, according to Agrawal, was less than euphonius. Fremling, who had tried his own hand at setting down sounds in relationship to each supernova, had the same result: The music, he said, "did not sound good at all."

"I don't think I realized how many notes 8,000 actually is," Agrawal says. "I was definitely picturing it to be a lot slower and more spread out, but after converting the data to sound I heard how densely packed the notes were."

To achieve a sparser texture, Agrawal slowed the tempo of the sound file, extending its length to about 30 minutes, and then set about manipulating and enhancing the musicality of the piece. To ensure that the music would evoke outer space, Agrawal rounded pitches to fit into what is known as the Lydian augmented mode, a scale that begins with whole tones which, Agrawal says, "feel less settled and rooted than ordinary major or minor scales. This resembles the scales in sci-fi music, so I thought it would be beneficial for representing the vastness of space." Agrawal then added a percussion track, a chord track that harmonized dominant pitches in the dataset, and effects such as the sound of wind and distorted chattering.

"There is an element of subjectivity in this," Agrawal says, "because, of course, the music isn't what space actually sounds like, even before I began adding musical tracks. It's my interaction with the universe, my interpretation of it through sound. I would find it interesting to hear how other people sonify the same data, how they interact with the same universe."

Agrawal's composition has already been published on the ZTF website, along with a short video of supernova discoveries that uses portions of Agrawal's composition for background music. But Agrawal's imagination reaches well beyond her first composition: "Obviously the parameters will be different for every dataset, but this type of sonification can be done with any dataset. And with the right algorithms, sonifications can be created automatically and in real time. These compositions could be published on streaming services or played within planetariums, helping astrophysics discoveries to reach wider audiences."

Until those algorithms come along, Fremling, Agrawal, and the outreach coordinator of ZTF have created the resources and tutorials needed to enable anyone to sonify ZTF datasets. The aim is to build a library of sonifications that can be offered to educators, artists, science engagement centers, astronomy visualization professionals, and more to improve and enrich accessibility to science. All resources are available.

Of course, new data will come along to shift our perspective on supernovae, and as a consequence, musical compositions featuring them will change too. "Just within the last year or two we have found a new type of supernova, even though people have been studying supernovae since the 1940s and 1950s," Fremling says. Agrawal will need to introduce another instrument into her orchestra. Also, supernova data can be interpreted in different ways. For example, Fremling notes, "some types of supernovae are inherently always very similar in absolute luminosity. The only reason their luminosity varies in the dataset—which Agrawal has translated into volume in her composition—is because these supernovae are occurring at different distances from our observatory at Palomar."

Agrawal is bound for Washington University in St. Louis in fall 2024, planning to double major in music and astrophysics.

Try your own hand at sonifying supernovae!

Written by Cynthia Eller

Source: Caltech/News

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Contact:

Cynthia Eller
celler@caltech.edu

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