QuoteAre those unusually tiny error bars? I'm only going by eye-balling other transit spectra I've seen in pop.sci articles, but that seems insanely clean.Exactly – JWST has moved this game into another dimension completely. It’s remarkable what a big cold space telescope with great instrumentation will do
Are those unusually tiny error bars? I'm only going by eye-balling other transit spectra I've seen in pop.sci articles, but that seems insanely clean.
NASA’s Webb Detects Carbon Dioxide in Exoplanet AtmosphereAug. 25, 2022Webb ushers in a new era of exoplanet science with the first unequivocal detection of carbon dioxide in a planetary atmosphere outside our solar system.NASA’s James Webb Space Telescope has captured the first clear evidence for carbon dioxide in the atmosphere of a planet outside the solar system. This observation of a gas giant planet orbiting a Sun-like star 700 light-years away provides important insights into the composition and formation of the planet. The finding, which is accepted for publication in Nature, offers evidence that in the future Webb may be able to detect and measure carbon dioxide in the thinner atmospheres of smaller, rocky planets.WASP-39 b is a hot gas giant with a mass roughly one-quarter that of Jupiter (about the same as Saturn) and a diameter 1.3 times greater than Jupiter’s. Its extreme puffiness is related in part to its high temperature (about 1,600 degrees Fahrenheit, or 900 degrees Celsius). Unlike the cooler, more compact gas giants in our solar system, WASP-39 b orbits very close to its star – only about one-eighth the distance between the Sun and Mercury – completing one circuit in just over four Earth days. The planet’s discovery, reported in 2011, was made based on ground-based detections of the subtle, periodic dimming of light from its host star as the planet transits, or passes in front of the star.Previous observations from other telescopes, including NASA’s Hubble and Spitzer space telescopes, revealed the presence of water vapor, sodium, and potassium in the planet’s atmosphere. Webb’s unmatched infrared sensitivity has now confirmed the presence of carbon dioxide on this planet as well.Filtered StarlightTransiting planets like WASP-39 b, whose orbits we observe edge-on rather than from above, can provide researchers with ideal opportunities to probe planetary atmospheres.During a transit, some of the starlight is eclipsed by the planet completely (causing the overall dimming) and some is transmitted through the planet’s atmosphere.Because different gases absorb different combinations of colors, researchers can analyze small differences in brightness of the transmitted light across a spectrum of wavelengths to determine exactly what an atmosphere is made of. With its combination of inflated atmosphere and frequent transits, WASP-39 b is an ideal target for transmission spectroscopy.First Clear Detection of Carbon DioxideThe research team used Webb’s Near-Infrared Spectrograph (NIRSpec) for its observations of WASP-39 b. In the resulting spectrum of the exoplanet’s atmosphere, a small hill between 4.1 and 4.6 microns presents the first clear, detailed evidence for carbon dioxide ever detected in a planet outside the solar system.“As soon as the data appeared on my screen, the whopping carbon dioxide feature grabbed me,” said Zafar Rustamkulov, a graduate student at Johns Hopkins University and member of the JWST Transiting Exoplanet Community Early Release Science team, which undertook this investigation. “It was a special moment, crossing an important threshold in exoplanet sciences.”No observatory has ever measured such subtle differences in brightness of so many individual colors across the 3- to 5.5-micron range in an exoplanet transmission spectrum before. Access to this part of the spectrum is crucial for measuring abundances of gases like water and methane, as well as carbon dioxide, which are thought to exist in many different types of exoplanets.“Detecting such a clear signal of carbon dioxide on WASP-39 b bodes well for the detection of atmospheres on smaller, terrestrial-sized planets,” said Natalie Batalha of the University of California at Santa Cruz, who leads the team.Understanding the composition of a planet’s atmosphere is important because it tells us something about the origin of the planet and how it evolved. “Carbon dioxide molecules are sensitive tracers of the story of planet formation,” said Mike Line of Arizona State University, another member of this research team. “By measuring this carbon dioxide feature, we can determine how much solid versus how much gaseous material was used to form this gas giant planet. In the coming decade, JWST will make this measurement for a variety of planets, providing insight into the details of how planets form and the uniqueness of our own solar system.”Early Release ScienceThis NIRSpec prism observation of WASP-39 b is just one part of a larger investigation that includes observations of the planet using multiple Webb instruments, as well as observations of two other transiting planets. The investigation, which is part of the Early Release Science program, was designed to provide the exoplanet research community with robust Webb data as soon as possible.“The goal is to analyze the Early Release Science observations quickly and develop open-source tools for the science community to use,” explained Vivien Parmentier, a co-investigator from Oxford University. “This enables contributions from all over the world and ensures that the best possible science will come out of the coming decades of observations.”Natasha Batalha, co-author on the paper from NASA’s Ames Research Center, added that “NASA’s open science guiding principles are centered in our Early Release Science work, supporting an inclusive, transparent, and collaborative scientific process.”The James Webb Space Telescope is the world’s premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe 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 the Canadian Space Agency.
This illustration shows what exoplanet WASP-39 b could look like, based on current understanding of the planet. WASP-39 b is a hot, puffy gas giant with a mass 0.28 times Jupiter (0.94 times Saturn) and a diameter 1.3 times greater than Jupiter. Credit: NASA, ESA, CSA, Joseph Olmsted (STScI)
A series of light curves from Webb’s Near-Infrared Spectrograph (NIRSpec) shows the change in brightness of three different wavelengths (colors) of light from the WASP-39 star system over time as the planet transited the star July 10, 2022. Credit: NASA, ESA, CSA, and L. Hustak (STScI); Science: The JWST Transiting Exoplanet Community Early Release Science Team
A transmission spectrum of the hot gas giant exoplanet WASP-39 b captured by Webb’s Near-Infrared Spectrograph (NIRSpec) July 10, 2022, reveals the first clear evidence for carbon dioxide in a planet outside the solar system. This is also the first detailed exoplanet transmission spectrum ever captured that covers wavelengths between 3 and 5.5 microns. Credit: Illustration: NASA, ESA, CSA, and L. Hustak (STScI); Science: The JWST Transiting Exoplanet Community Early Release Science Team
Webb inspects the heart of the Phantom Galaxy29/08/2022ESA / Science & Exploration / Space Science / WebbNew images of the spectacular Phantom Galaxy, M74, showcase the power of space observatories working together in multiple wavelengths. In this case, data from the NASA/ESA/CSA James Webb Space Telescope and the NASA/ESA Hubble Space Telescope complement each other to provide a comprehensive view of the galaxy.The Phantom Galaxy is around 32 million light-years away from Earth in the constellation Pisces, and lies almost face-on to Earth. This, coupled with its well-defined spiral arms, makes it a favourite target for astronomers studying the origin and structure of galactic spirals.M74 is a particular class of spiral galaxy known as a ‘grand design spiral’, meaning that its spiral arms are prominent and well-defined, unlike the patchy and ragged structure seen in some spiral galaxies.Webb’s sharp vision has revealed delicate filaments of gas and dust in the grandiose spiral arms of M74, which wind outwards from the centre of the image. A lack of gas in the nuclear region also provides an unobscured view of the nuclear star cluster at the galaxy's centre.Webb gazed into M74 with its Mid-InfraRed Instrument (MIRI) in order to learn more about the earliest phases of star formation in the local Universe. These observations are part of a larger effort to chart 19 nearby star-forming galaxies in the infrared by the international PHANGS collaboration. Those galaxies have already been observed using the NASA/ESA Hubble Space Telescope and ground-based observatories.The addition of crystal-clear Webb observations at longer wavelengths will allow astronomers to pinpoint star-forming regions in the galaxies, accurately measure the masses and ages of star clusters, and gain insights into the nature of the small grains of dust drifting in interstellar space. Hubble observations of M74 have revealed particularly bright areas of star formation known as HII regions. Hubble’s sharp vision at ultraviolet and visible wavelengths complements Webb’s unparalleled sensitivity at infrared wavelengths, as do observations from ground-based radio telescopes such as the Atacama Large Millimeter/submillimeter Array, ALMA.By combining data from telescopes operating across the electromagnetic spectrum, scientists can gain greater insight into astronomical objects than by using a single observatory – even one as powerful as Webb!
The first scientific results have emerged in recent weeks, and what the telescope has seen in deepest space is a little puzzling. Some of those distant galaxies are strikingly massive. A general assumption had been that early galaxies — which formed not long after the first stars ignited — would be relatively small and misshapen. Instead, some of them are big, bright and nicely structured.“The models just don’t predict this,” Garth Illingworth, an astronomer at the University of California at Santa Cruz, said of the massive early galaxies. “How do you do this in the universe at such an early time? How do you form so many stars so quickly?”
The easiest explanation for those surprisingly massive galaxies is that, at least for some of them, there’s been a miscalculation — perhaps due to a trick of light.The distant galaxies are very red. They are, in astronomical lingo, “redshifted.” The wavelengths of light from these objects have been stretched by the expansion of the universe. The ones that look the reddest — that have the highest redshift — are presumed to be the farthest away.But dust can be throwing off the calculations. Dust can absorb blue light, and redden the object. It could be that some of these very distant, highly redshifted galaxies are just very dusty, and not actually as far away (and as “young”) as they appear. That would realign the observations with what astronomers expected.Or some other explanation could surface.
Webb telescope is already challenging what astronomers thought they knewQuote The first scientific results have emerged in recent weeks, and what the telescope has seen in deepest space is a little puzzling. Some of those distant galaxies are strikingly massive. A general assumption had been that early galaxies — which formed not long after the first stars ignited — would be relatively small and misshapen. Instead, some of them are big, bright and nicely structured.“The models just don’t predict this,” Garth Illingworth, an astronomer at the University of California at Santa Cruz, said of the massive early galaxies. “How do you do this in the universe at such an early time? How do you form so many stars so quickly?”Quote The easiest explanation for those surprisingly massive galaxies is that, at least for some of them, there’s been a miscalculation — perhaps due to a trick of light.The distant galaxies are very red. They are, in astronomical lingo, “redshifted.” The wavelengths of light from these objects have been stretched by the expansion of the universe. The ones that look the reddest — that have the highest redshift — are presumed to be the farthest away.But dust can be throwing off the calculations. Dust can absorb blue light, and redden the object. It could be that some of these very distant, highly redshifted galaxies are just very dusty, and not actually as far away (and as “young”) as they appear. That would realign the observations with what astronomers expected.Or some other explanation could surface.https://www.washingtonpost.com/science/2022/08/26/webb-telescope-space-jupiter-galaxy/
Quote from: Star One on 08/30/2022 03:48 pmWebb telescope is already challenging what astronomers thought they knewQuote The first scientific results have emerged in recent weeks, and what the telescope has seen in deepest space is a little puzzling. Some of those distant galaxies are strikingly massive. A general assumption had been that early galaxies — which formed not long after the first stars ignited — would be relatively small and misshapen. Instead, some of them are big, bright and nicely structured.“The models just don’t predict this,” Garth Illingworth, an astronomer at the University of California at Santa Cruz, said of the massive early galaxies. “How do you do this in the universe at such an early time? How do you form so many stars so quickly?”Quote The easiest explanation for those surprisingly massive galaxies is that, at least for some of them, there’s been a miscalculation — perhaps due to a trick of light.The distant galaxies are very red. They are, in astronomical lingo, “redshifted.” The wavelengths of light from these objects have been stretched by the expansion of the universe. The ones that look the reddest — that have the highest redshift — are presumed to be the farthest away.But dust can be throwing off the calculations. Dust can absorb blue light, and redden the object. It could be that some of these very distant, highly redshifted galaxies are just very dusty, and not actually as far away (and as “young”) as they appear. That would realign the observations with what astronomers expected.Or some other explanation could surface.https://www.washingtonpost.com/science/2022/08/26/webb-telescope-space-jupiter-galaxy/This makes no sense. You don't measure red shift by comparing color intensities. You measure red shift by looking at specific lines in the spectrum. Even if they are differentially attenuated, they are still there.
[This makes no sense. You don't measure red shift by comparing color intensities. You measure red shift by looking at specific lines in the spectrum. Even if they are differentially attenuated, they are still there.
This makes no sense. You don't measure red shift by comparing color intensities. You measure red shift by looking at specific lines in the spectrum. Even if they are differentially attenuated, they are still there.
Quote from: DanClemmensen on 08/30/2022 03:54 pmQuote from: Star One on 08/30/2022 03:48 pmWebb telescope is already challenging what astronomers thought they knewQuote The first scientific results have emerged in recent weeks, and what the telescope has seen in deepest space is a little puzzling. Some of those distant galaxies are strikingly massive. A general assumption had been that early galaxies — which formed not long after the first stars ignited — would be relatively small and misshapen. Instead, some of them are big, bright and nicely structured.“The models just don’t predict this,” Garth Illingworth, an astronomer at the University of California at Santa Cruz, said of the massive early galaxies. “How do you do this in the universe at such an early time? How do you form so many stars so quickly?”Quote The easiest explanation for those surprisingly massive galaxies is that, at least for some of them, there’s been a miscalculation — perhaps due to a trick of light.The distant galaxies are very red. They are, in astronomical lingo, “redshifted.” The wavelengths of light from these objects have been stretched by the expansion of the universe. The ones that look the reddest — that have the highest redshift — are presumed to be the farthest away.But dust can be throwing off the calculations. Dust can absorb blue light, and redden the object. It could be that some of these very distant, highly redshifted galaxies are just very dusty, and not actually as far away (and as “young”) as they appear. That would realign the observations with what astronomers expected.Or some other explanation could surface.https://www.washingtonpost.com/science/2022/08/26/webb-telescope-space-jupiter-galaxy/This makes no sense. You don't measure red shift by comparing color intensities. You measure red shift by looking at specific lines in the spectrum. Even if they are differentially attenuated, they are still there.There are indeed materials which shift wavelengths. They are used in scintillators. However, I don't think they can nicely shift entire spectrum redwards. And they are organic chemicals, doubt they'd be widely present in dust.http://kuraraypsf.jp/psf/ws.html
The same team of researchers that last week took the James Web Space Telescope’s (JWST) first direct image of a planet outside our solar system has confirmed the presence of smoke-like silica clouds in the atmosphere of another.Hypothesized for many years, the finding published in a new (non-peer reviewed) paper reveals that an exoplanet called VHS 1256 b has a violent and turbulent atmosphere that is filled with clouds.Except that these clouds are not made from water vapor droplets, but smoke-like particles of silicate. “A better way to think of these clouds are objects that are made of tiny-particles ... except that these silicate clouds are made of the same thing that grains of sand are made of,” said Sasha Hinkley, Associate Professor in the Department of Physics & Astronomy at the University of Exeter and Principal Investigator for one of the 13 JWST Early Release Science Programs.Astronomers that model exoplanet atmospheres using computers have predicted for decades that these smoke-like particles should exist in these atmospheres, but only JWST has the wavelength coverage to definitively detect them.
The James Webb Space Telescope captured its first images and spectra of Mars on 5 September 2022. The telescope, an international collaboration between NASA, ESA and the Canadian Space Agency, provides a unique perspective with its infrared sensitivity on our neighbouring planet, complementing data being collected by orbiters, rovers, and other telescopes.Webb’s unique observation post nearly 1.5 million kilometres away at the Sun-Earth Lagrange point 2 (L2) provides a view of Mars’ observable disk (the portion of the sunlit side that is facing the telescope). As a result, Webb can capture images and spectra with the spectral resolution needed to study short-term phenomena like dust storms, weather patterns, seasonal changes, and, in a single observation, processes that occur at different times (daytime, sunset, and nighttime) of a Martian day.Because it is so close, the Red Planet is one of the brightest objects in the night sky in terms of both visible light (which human eyes can see) and the infrared light that Webb is designed to detect. This poses special challenges to the observatory, which was built to detect the extremely faint light of the most distant galaxies in the universe. Webb’s instruments are so sensitive that without special observing techniques, the bright infrared light from Mars is blinding, causing a phenomenon known as “detector saturation.” Astronomers adjusted for Mars’ extreme brightness by using very short exposures, measuring only some of the light that hit the detectors, and applying special data analysis techniques.Webb’s first images of Mars, captured by the Near-Infrared Camera (NIRCam), show a region of the planet’s eastern hemisphere at two different wavelengths, or colours of infrared light. This image shows a surface reference map from NASA and the Mars Orbiter Laser Altimeter (MOLA) on the left, with the two Webb NIRCam instrument field of views overlaid. The near-infrared images from Webb are shown on the right.Webb’s first near-infrared spectrum of Mars, captured by the Near-Infrared Spectrograph (NIRSpec), demonstrates Webb’s power to study the Red Planet with spectroscopy.Whereas the Mars images show differences in brightness integrated over a large number of wavelengths from place to place across the planet at a particular day and time, the spectrum shows the subtle variations in brightness between hundreds of different wavelengths representative of the planet as a whole. Astronomers will analyse the features of the spectrum to gather additional information about the surface and atmosphere of the planet.In the future, Webb will be using this imaging and spectroscopic data to explore regional differences across the planet, and to search for trace species in the atmosphere, including methane and hydrogen chloride.These observations of Mars were conducted as part of Webb’s Cycle 1 Guaranteed Time Observation (GTO) Solar System program led by Heidi Hammel of the Association of Universities for Research in Astronomy (AURA).ESA operates two Mars orbiters, Mars Express and the ExoMars Trace Gas Orbiter, that have brought a treasury of insight into the Red Planet’s atmosphere and surface. Furthermore, ESA collaborates with the Japanese Aerospace Exploration Agency (JAXA) on the Martian Moons eXploration (MMX) mission, soon to launch for Mars’ moon Phobos.NIRSpec was built for the European Space Agency (ESA) by a consortium of European companies led by Airbus Defence and Space (ADS) with NASA’s Goddard Space Flight Centre providing its detector and micro-shutter subsystems.Note: This post highlights images from Webb science in progress, which has not yet been through the peer-review process.
But a new MIT study suggests that the tools astronomers typically use to decode light-based signals may not be good enough to accurately interpret the new telescope’s data. Specifically, opacity models — the tools that model how light interacts with matter as a function of the matter’s properties — may need significant retuning in order to match the precision of JWST data, the researchers say.If these models are not refined? The researchers predict that properties of planetary atmospheres, such as their temperature, pressure, and elemental composition, could be off by an order of magnitude.“There is a scientifically significant difference between a compound like water being present at 5 percent versus 25 percent, which current models cannot differentiate,” says study co-leader Julien de Wit, assistant professor in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS).“Currently, the model we use to decrypt spectral information is not up to par with the precision and quality of data we have from the James Webb telescope,” adds EAPS graduate student Prajwal Niraula. “We need to up our game and tackle together the opacity problem.”De Wit, Niraula, and their colleagues have published their study today in Nature Astronomy. Co-authors include spectroscopy experts Iouli Gordon, Robert Hargreaves, Clara Sousa-Silva, and Roman Kochanov of the Harvard-Smithsonian Center for Astrophysics.
He and his colleagues raise some ideas for how to improve existing opacity models, including the need for more laboratory measurements and theoretical calculations to refine the models’ assumptions of how light and various molecules interact, as well as collaborations across disciplines, and in particular, between astronomy and spectroscopy.“In order to reliably interpret spectra from the diverse exoplanetary atmospheres, we need an extensive campaign for new accurate measurements and calculations of relevant molecular spectroscopic parameters,” says study co-author Iouli Gordon, a physicist at the Harvard-Smithsonian Center for Astrophysics. “These parameters will need to be timely implemented into reference spectroscopic databases and consequently models used by astronomers."“There is so much that could be done if we knew perfectly how light and matter interact,” Niraula adds. “We know that well enough around the Earth’s conditions, but as soon as we move to different types of atmospheres, things change, and that’s a lot of data, with increasing quality, that we risk misinterpreting.”
