Tag: Webb

Communications issue shuts down one of Webb’s instruments

8:30 am

The near infrared instrument on the Webb Space Telescope, NIRISS, has been unavailable for science observations for more than a week due to a communications issue.

On Sunday, Jan. 15, the James Webb Space Telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) experienced a communications delay within the instrument, causing its flight software to time out. The instrument is currently unavailable for science observations while NASA and the Canadian Space Agency (CSA) work together to determine and correct the root cause of the delay.

According to the update, the instrument’s hardware, as well as the rest of the telescope, has been unaffected and remains in good condition.

In November the telescope’s mid-infrared instrument MIRI experienced its own problems with one of its “grating wheels” that allows it to some spectroscopy. Since then the instrument has been in use, but it is unclear if the issue was resolved or observations have had to be adjusted to avoid the problem.

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First exoplanet confirmed by Webb

10:23 am

Astronomers have used for the first time the Webb Space Telescope to confirm the existence of an exoplanet, previous noted in data from the orbiting TESS telescope.

Formally classified as LHS 475 b, the planet is almost exactly the same size as our own, clocking in at 99% of Earth’s diameter. The research team is led by Kevin Stevenson and Jacob Lustig-Yaeger, both of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

The team chose to observe this target with Webb after carefully reviewing targets of interest from NASA’s Transiting Exoplanet Survey Satellite (TESS), which hinted at the planet’s existence. Webb’s Near-Infrared Spectrograph (NIRSpec) captured the planet easily and clearly with only two transit observations.

The data is still preliminary, so more analysis is necessary to provide some information about the planet’s atmosphere.

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Webb finds “wide diversity of galaxies in the early universe”

12:35 pm

Webb galaxies in the early universe
Click for full image.

New data from the Webb Space Telescope and presented this week at an astronomy conference has found that galaxies in the early universe exhibit much of the same range of shapes and morphologies seen in the recent universe, a result that was not expected.

The image to the right comes from the press release. You can read the research paper here [pdf].

The study examined 850 galaxies at redshifts of z three through nine, or as they were roughly 11-13 billion years ago. Associate Professor Jeyhan Kartaltepe from Rochester Institute of Technology’s School of Physics and Astronomy said that JWST’s ability to see faint high redshift galaxies in sharper detail than Hubble allowed the team of researchers to resolve more features and see a wide mix of galaxies, including many with mature features such as disks and spheroidal components.

“There have been previous studies emphasizing that we see a lot of galaxies with disks at high redshift, which is true, but in this study we also see a lot of galaxies with other structures, such as spheroids and irregular shapes, as we do at lower redshifts,” said Kartaltepe, lead author on the paper and CEERS co-investigator. “This means that even at these high redshifts, galaxies were already fairly evolved and had a wide range of structures.”

The results of the study, which have been posted to ArXiv and accepted for publication in The Astrophysical Journal, demonstrate JWST’s advances in depth, resolution, and wavelength coverage compared to Hubble. Out of the 850 galaxies used in the study that were previously identified by Hubble, 488 were reclassified with different morphologies after being shown in more detail with JWST. Kartaltepe said scientists are just beginning to reap the benefits of JWST’s impressive capabilities and are excited by what forthcoming data will reveal.

“This tells us that we don’t yet know when the earliest galaxy structures formed,” said Kartaltepe. “We’re not yet seeing the very first galaxies with disks. We’ll have to examine a lot more galaxies at even higher redshifts to really quantify at what point in time features like disks were able to form.”

In other words, it appears galaxies of all shapes, as we see them today, already existed 11-13 billion years ago, shortly after the universe was born. This defies most theories about the formation of the universe, which predict that these early galaxies would be different than today’s.

The data however at this point is sparse. Webb has only begun this work, and as Kartaltepe notes, they need to look a lot more galaxies.

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Today’s blacklisted American: Black scientist blacklisted for doing good research

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Oluseyi Hakeem, blacklisted
Hakeem Oluseyi, Space Science Education Lead
for NASA’s Science Mission Directorate

They’re coming for you next: Today’s blacklist column describes an effort to not only cancel from history the man who led NASA for almost the entire 1960s space race, but to also blackball a scientist for doing good research that proved the campaign was not based on any facts.

Shortly before the launch of the James Webb Space Telescope last year, a petition was instigated to get it renamed because of accusations that Webb had persecuted homosexuals during his term as NASA administrator in the 1960s. As is now typical of our modern bankrupt intellectual class, as soon as this petition was issued more than 1,700 people signed it, all accepting at face value its accusations against Webb without any further research.

One scientist, who happened to be black, took a more detailed look at those accusations however and found them to be spurious. As Hakeem Oluseyi wrote:
» Read more

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Webb in safe mode intermittently during the past two weeks

2:49 pm

According to a short update today from the science team, the Webb Space Telescope went into safe mode on December 7, 2022 and was in that state “intermittently” through December 20, 2022 because of a software issue.

The James Webb Space Telescope resumed science operations Dec. 20, after Webb’s instruments intermittently went into safe mode beginning Dec. 7 due to a software fault triggered in the attitude control system, which controls the pointing of the observatory. During a safe mode, the observatory’s nonessential systems are automatically turned off, placing it in a protected state until the problem can be fixed. This event resulted in several pauses to science operations totaling a few days over that time period. Science proceeded otherwise during that time. The Webb team adjusted the commanding system, and science has now fully resumed.

It would be nice to have a more detailed description of that “software fault”, and how it affected the attitude control system. Such things can be very trivial, or they can be disastrous. NASA has a responsibility to tell the public which.

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Astronomers confirm Webb galaxies from the early universe

9:40 am

Astronomers using Webb have now confirmed with spectroscopy the age of at least four galaxies from the very very early universe, existing only a short time after the theorized Big Bang.

Four of the galaxies studied are particularly special, as they were revealed to be at an unprecedentedly early epoch. The results provided spectroscopic confirmation that these four galaxies lie at redshifts above 10, including two at redshift 13. This corresponds to a time when the universe was approximately 330 million years old, setting a new frontier in the search for far-flung galaxies. These galaxies are extremely faint because of their great distance from us.

The scientists had aimed Webb at Hubble’s Ultra Deep Field, doing a long infrared exposure lasting 28 hours over three days in order to gather the faintest infrared radiation (that Hubble could not see) and thus the most distant galaxies. The spectrum of individuals stars was then measured, which indicating their redshift and their estimated age.

The astronomers will next aim Webb at the more famous Hubble Deep Field, the first such long exposure that optical telescope took back in the late 1990s.

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Webb’s infrared view of the Southern Ring Nebula

4:57 pm

Two views of Southern Ring Nebula by Webb
Click for original image.

The two images to the left were produced by the Webb Space Telescope, showing in false colors the Southern Ring Nebula as seen by two of Webb’s infrared cameras.

The two images shown here each combine near-infrared and mid-infrared data to isolate different components of the nebula. The image at [top] highlights the very hot gas that surrounds the central stars. The image at [bottom] traces the star’s scattered molecular outflows that have reached farther into the cosmos.

Based on the data, astronomers posit that up the system could have as many as five stars orbiting each other, with three as yet unseen, or the inner ones might no longer exist, having been absorbed by the bigger stars.

It’s possible more than one star interacted with the dimmer of the two central stars, which appears red in this image, before it created this jaw-dropping planetary nebula. The first star that “danced” with the party’s host created a light show, sending out jets of material in opposite directions. Before retiring, it gave the dim star a cloak of dust. Now much smaller, the same dancer might have merged with the dying star – or is now hidden in its glare.

A third partygoer may have gotten close to the central star multiple times. That star stirred up the jets ejected by the first companion, which helped create the wavy shapes we see today at the edges of the gas and dust. Not to be left out, a fourth star with an orbit projected to be much wider, also contributed to the celebration. It circled the scene, further stirring up the gas and dust, and generating the enormous system of rings seen outside the nebula. The fifth star is the best known – it’s the bright white-blue star visible in the images that continues to orbit predictably and calmly.

Much of this remains mere theory, based on the available data. Nonetheless, the data from many such planetary nebula continues to suggest their strange and wonderful shapes are created by multiple stars, acting as a mix-master to churn up the nebula’s dust.

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Webb and Keck telescopes track clouds on Titan

11:08 am

Clouds on Titan
Click for original image.

Astronomers have used the Webb Space Telescope and the Keck Observatory in Hawaii to take infrared images days apart of the evolving clouds on the Saturn moon Titan.

The false-color infrared images to the right are those observations. From the press release:

As part of their investigation of Titan’s atmosphere and climate, Nixon’s team used JWST’s Near-Infrared Camera (NIRCam) to observe the moon during the first week of November. After seeing the clouds near Kraken Mare, the largest known liquid sea of methane on the surface of Titan, they immediately contacted the Keck Titan Observing Team to request follow-up observations.

“We were concerned that the clouds would be gone when we looked at Titan a day later with Keck, but to our delight there were clouds at the same positions on subsequent observing nights, looking like they had changed in shape,” said Imke de Pater, emeritus professor of astronomy at the University of California, Berkeley, who leads the Keck Titan Observing Team.

Using Keck Observatory’s second generation Near-Infrared Camera (NIRC2) in combination with the Keck II Telescope’s adaptive optics system, de Pater and her team observed one of Titan’s clouds rotating into and another cloud either dissipating or moving out of Earth’s field of view due to Titan’s rotation.

These images only increase my mourning for a Saturn orbiter. Since the end of Cassini’s mission in 2017, we have essentially been blind to the ringed planet and its many moons. These images, while producing excellent data, also illustrate well what we have lost.

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Webb makes its first detailed survey of an exoplanet’s atmosphere

9:23 am

Astronomers have now completed the first detailed survey of an exoplanet’s atmosphere using the Webb Space Telescope, looking at a gas giant about one third the mass of Jupiter about 700 light years away.

Using three of its instruments, JWST was able to observe light from the planet’s star as it filtered through WASP-39b’s atmosphere, a process known as transmission spectroscopy. This allowed a team of more than 300 astronomers to detect water, carbon monoxide, sodium, potassium and more in the planet’s atmosphere, in addition to the carbon dioxide. The gives the planet a similar composition to Saturn, although it has no detectable rings.

The team were also surprised to detect sulfur dioxide, which had appeared as a mysterious bump in early observation data. Its presence suggests a photochemical reaction is taking place in the atmosphere as light from the star hits it, similar to how our Sun produces ozone in Earth’s atmosphere. In WASP-39b’s case, light from its star, slightly smaller than the Sun, splits water in its atmosphere into hydrogen and hydroxide, which reacts with hydrogen sulfide to produce sulfur dioxide.

The data also suggested the clouds in the atmosphere are patchy, and that the planet’s formation process was not exactly as predicted.

These observations are part of a program to study 70 exoplanets during Webb’s first year of operation, using its infrared capabilities to get spectroscopy not possible in other wavelengths.

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Webb finding more galaxies in early universe than expected

10:52 am

The uncertainty of science: Astronomers using the Webb Space Telescope are finding in very early universe many more galaxies that are also far more developed then had been predicted.

The Webb observations nudge astronomers toward a consensus that an unusual number of galaxies in the early universe were so much brighter than expected. This will make it easier for Webb to find even more early galaxies in subsequent deep sky surveys, say researchers.

“We’ve nailed something that is incredibly fascinating. These galaxies would have had to have started coming together maybe just 100 million years after the big bang. Nobody expected that the dark ages would have ended so early,” said Garth Illingworth of the University of California at Santa Cruz, a member of the Naidu/Oesch team. “The primal universe would have been just one hundredth its current age. It’s a sliver of time in the 13.8 billion-year-old evolving cosmos.”

Erica Nelson of the University of Colorado in Boulder, a member of the Naidu/Oesch team, noted that “our team was struck by being able to measure the shapes of these first galaxies; their calm, orderly disks question our understanding of how the first galaxies formed in the crowded, chaotic early universe.”

The galaxies are smaller, more compact than present day galaxies, and appear to be forming stars at a tremendous rate. Because their distances, presently estimated, still need to be confirmed by spectroscopy, these conclusions remain somewhat tentative though quite alluring.

We should not be surprised if in the next two years data from Webb will overturn almost all the theories that presently exist about the Big Bang and its immediate aftermath.

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A hidden baby star, seen in infrared

9:44 am

A hidden baby star, seen in infrared
Click for original image.

Using the Webb Space Telescope, astronomers have obtained a new high resolution infrared false color view of the bi-polar jets of a new solar system and star, hidden within its dark cloud of dust.

That image is the photo to the right, reduced and sharpened to post here. From the press release:

NASA’s James Webb Space Telescope has revealed the once-hidden features of the protostar within the dark cloud L1527, providing insight into the beginnings of a new star. These blazing clouds within the Taurus star-forming region are only visible in infrared light, making it an ideal target for Webb’s Near-Infrared Camera (NIRCam).

The protostar itself is hidden from view within the “neck” of this hourglass shape. An edge-on protoplanetary disk is seen as a dark line across the middle of the neck. Light from the protostar leaks above and below this disk, illuminating cavities within the surrounding gas and dust.

The region’s most prevalent features, the clouds colored blue and orange in this representative-color infrared image, outline cavities created as material shoots away from the protostar and collides with surrounding matter. The colors themselves are due to layers of dust between Webb and the clouds. The blue areas are where the dust is thinnest. The thicker the layer of dust, the less blue light is able to escape, creating pockets of orange.

Scientists estimate this star is only about 100,000 years old, and is in its earliest stage of formation. That protoplanetary disk is estimated to be about the size of our solar system.

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Webb’s mid-infrared instrument restored to full operations

9:16 am

Engineers have figured out the issue on the mid-infrared instrument on the Webb Space Telescope that was causing increased friction during operations, and are now ready to return it to full operations.

The team concluded the issue is likely caused by increased contact forces between sub-components of the wheel central bearing assembly under certain conditions. Based on this, the team developed and vetted a plan for how to use the affected mechanism during science operations.

An engineering test was executed Wednesday, Nov. 2, that successfully demonstrated predictions for wheel friction. Webb will resume MIRI MRS science observations by Saturday, Nov. 12.

Webb has three other infrared instruments, looking at different infrared wavelengths, so this issue had not prevented the telescope from doing most of its observations. Losing MIRI however would have been a very bad blow, this soon after launch.

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Rate of micrometeorite impacts on Webb holding as expected

10:10 am

According to this Space.com article, the rate and size of micrometeorite impacts on the main mirror of the Webb Space Telescope has held steady at the rate and size expected, since the first surprisingly large micrometeorite impact in May that slightly dinged one mirror segment.

At this point, JWST has experienced a total of 33 micrometeoroid events, according to Smith’s slides. But the most damaging one came before JWST began science observations; in late May, a particularly large micrometeoroid struck the observatory’s mirror, leaving its mark on one golden hexagon. The team estimates that a strike of that size should occur about once a year, Smith said.

“So we got that at month five,” he said. “We haven’t seen another one yet, so it’s still consistent with the statistics that we expected.”

Smith noted that, at the current impact rate, Webb will still be meeting its five-year performance requirement 10 years into the mission. Scientists estimate that the observatory has enough fuel to operate for 20 years.

Meanwhile, one of Webb’s infrared cameras is not doing spectroscopy as engineers analyze the high levels of friction in a “grating wheel.” At this point it appears they still do not understand the cause of the friction, and thus have not come up with a plan for mitigating it.

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Webb takes infrared image of Hubble’s Pillars of Creation

10:28 am

The Pillars of Creation, as seen by Hubble and Webb
Click for original image.

Not unexpectedly, astronomers have quickly begun aiming the Webb Space Telescope’s infrared eye at some of the most famous targets previously imaged in optical wavelengths by the Hubble Space Telescope.

The newest example is shown to the right and reduced and labeled to post here. It shows what NASA officials dubbed “The Pillars of Creation” when Hubble first photographed this nebula in 1995, with a later 2014 Hubble optical image at the top and the new 2022 Webb infrared image on the bottom. From this image’s caption:

A new, near-infrared-light view from NASA’s James Webb Space Telescope, at [bottom], helps us peer through more of the dust in this star-forming region. The thick, dusty brown pillars are no longer as opaque and many more red stars that are still forming come into view.

While the pillars of gas and dust seem darker and less penetrable in Hubble’s view [top], they appear more diaphanous in Webb’s. The background of this Hubble image is like a sunrise, beginning in yellows at the bottom, before transitioning to light green and deeper blues at the top. These colors highlight the thickness of the dust all around the pillars, which obscures many more stars in the overall region.

In contrast, the background light in Webb’s image appears in blue hues, which highlights the hydrogen atoms, and reveals an abundance of stars spread across the scene. By penetrating the dusty pillars, Webb also allows us to identify stars that have recently – or are about to – burst free. Near-infrared light can penetrate thick dust clouds, allowing us to learn so much more about this incredible scene.

While the Hubble colors attempt to mimic the colors seen by the human eye, the colors in the Webb image are all false colors, chosen by the scientists to distinguish the different infrared wavelengths produced by different features in the picture.

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Shells of dust surrounding massive binary star

10:07 am

Webb infrared image of dust shells surrounding binary star system
Click for full image.

Cool image time! Using the Webb telescope, astronomers have detected a series of concentric shells surrounding the massive binary star dubbed Wolf-Rayet 140.

The infrared image to the right shows these shells quite clearly. As noted by astronomer Ryan Lau:

“On the night that my team’s Early Release Science observations of the dust-forming massive binary star Wolf-Rayet (WR) 140 were taken, I was puzzled by what I saw in the preview images from the Mid-Infrared Instrument (MIRI). There seemed to be a strange-looking diffraction pattern, and I worried that it was a visual effect created by the stars’ extreme brightness. However, as soon as I downloaded the final data I realized that I was not looking at a diffraction pattern, but instead rings of dust surrounding WR 140 – at least 17 of them.

“I was amazed. Although they resemble rings in the image, the true 3D geometry of those semi-circular features is better described as a shell. The shells of dust are formed each time the stars reach a point in their orbit where they are closest to each other and their stellar winds interact. The even spacing between the shells indicates that dust formation events are occurring like clockwork, once in each eight-year orbit. In this case, the 17 shells can be counted like tree rings, showing more than 130 years of dust formation. Our confidence in this interpretation of the image was strengthened by comparing our findings to the geometric dust models by Yinuo Han, a doctoral student at the University of Cambridge, which showed a near-perfect match to our observations.

Furthermore, the spectroscopy from Webb says these dust shells are carbon-enriched, showing that the dust released by these aged massive stars is a significant source of the carbon in the universe, the fundamental atom needed for life.

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Webb gets first direct infrared image of exoplanet

10:21 am

Exoplanet as seen in the infrared by Webb

Using the Webb Space Telescope, scientists have obtained that telescope’s first direct infrared image of an exoplanet, covering four different wavelengths.

The image to the right is from the wavelength image with the least distortion (formed by Webb’s own optics and the shape of its mirror and indicated by the faint ring surrounding the planet). The star indicates the masked location of the star itself.

The planet is about seven times the mass of Jupiter and lies more than 100 times farther from its star than Earth sits from the sun, direct observations of exoplanet HIP 65426 b show. It’s also young, about 10 million or 20 million years old, compared with the more than 4-billion-year-old Earth.

You can download the full research paper here.

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Chandra takes an X-ray look at early Webb infrared observations

9:54 am

Chandra's X-ray vision of the Cartwheel Galaxy
Chandra’s X-ray view of the Cartwheel Galaxy

Webb's view of the Cartwheel Galaxy
Webb’s infrared view of the Cartwheel Galaxy
Click for full image.

Hubble's optical view of the Cartwheel Galaxy
Hubble’s optical view of the Cartwheel Galaxy. Click for original image.

Astronomers have now taken X-ray images using the orbital Chandra X-ray Observatory of four of the first Webb Space Telescope observations. The four targets were the Cartwheel Galaxy, Stephan’s Quintet, galaxy cluster SMACS 0723.3–7327, and the Carina Nebula.

The three images to the right illustrate the importance of studying astronomy across the entire electromagnetic spectrum. Each shows the Cartwheel Galaxy as seen by three of the world’s most important space-based telescopes, each looking at the galaxy in a different wavelength.

The top picture is Chandra’s new X-ray observations. As the press release notes,

Chandra data generally show higher-energy phenomena (like superheated gas and the remnants of exploded stars) than Webb’s infrared view. … X-rays seen by Chandra (blue and purple) come from superheated gas, individual exploded stars, and neutron stars and black holes pulling material from companion stars.

The middle picture was produced by Webb, shortly after the start of its science operations. It looks at the galaxy in the infrared.

In this near- and mid-infrared composite image, MIRI data are colored red while NIRCam data are colored blue, orange, and yellow. Amidst the red swirls of dust, there are many individual blue dots, which represent individual stars or pockets of star formation. NIRCam also defines the difference between the older star populations and dense dust in the core and the younger star populations outside of it.

The bottom picture was taken by the Hubble Space Telescope in 1995. I have rotated the image to match the others. It looks at the galaxy in optical wavelengths, the wavelengths that our eyes perceive.

Note how bright the central galactic region is in the infrared and optical, but is invisible in X-rays. Chandra is telling us that all the most active regions in the Cartwheel are located in that outer ring, not in its center.

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Initial Webb results revised because telescope wasn’t yet fully calibrated

10:02 am

The uncertainty of science: Though it appears that no results will have to be abandoned, the scientists who published some of the very first results from the Webb Space Telescope have been scrambling to adjust and revise their papers because the telescope is only now getting fully calibrated.

“This caused a little bit of panic,” says Nathan Adams, an astronomer at the University of Manchester, UK, who, along with his colleagues, pointed out the problem in a 9 August update to a preprint they had posted in late July3. “For those including myself who had written a paper within the first two weeks, it was a bit of — ‘Oh no, is everything that we’ve done wrong, does it all need to go in the bin?’”

To try to standardize all the measurements, the STScI is working through a detailed plan to point Webb at several types of well-understood star, and observe them with every detector in every mode for every instrument on the telescope4. “It just takes a while,” says Karl Gordon, an astronomer at the STScI who helps lead the effort.

In the meantime, astronomers have been reworking manuscripts that describe distant galaxies on the basis of Webb data. “Everyone’s gone back over and had a second look, and it’s not as bad as we thought,” Adams says. Many of the most exciting distant-galaxy candidates still seem to be at or near the distance originally estimated. But other preliminary studies, such as those that draw conclusions about the early Universe by comparing large numbers of faint galaxies, might not stand the test of time. Other fields of research, such as planetary studies, are not affected as much because they depend less on these preliminary brightness measurements.

Overall, it does not appear the more precise calibrations will change much of signficance, since most of the earliest observations were simply that, observations, not theoretical. Because the distance estimates remain largely unchanged however the theorists are left with the same conundrum: The age and apparent nature of the most distant objects does not seem to fit with what the theories had predicted Webb would see.

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Hubble & Webb make first coordinated observations, tracking DART impact of Dimorphus

9:50 am

Webb and Hubble together look at DART impact of Dimorphus
Click for full image.

For the first time scientists have used both the Hubble Space Telescope and the James Webb Space Telescope to observe the same astronomical event, in this case the impact of the DART spacecraft on the asteroid Dimorphus on September 26, 2022.

The two images to the right show the asteroid several hours after impact. Both telescopes also captured images before the impact as well. From the press release:

Observations from Webb and Hubble together will allow scientists to gain knowledge about the nature of the surface of Dimorphos, how much material was ejected by the collision, and how fast it was ejected. Additionally, Webb and Hubble captured the impact in different wavelengths of light – Webb in infrared and Hubble in visible. Observing the impact across a wide array of wavelengths will reveal the distribution of particle sizes in the expanding dust cloud, helping to determine whether it threw off lots of big chunks or mostly fine dust. Combining this information, along with ground-based telescope observations, will help scientists to understand how effectively a kinetic impact can modify an asteroid’s orbit.

When Webb was first conceived in the late 1990s, it was exactly for this reason, to combine Hubble’s optical vision with Webb’s infrared view. Though more than a decade late, it has finally happened.

It will be months before scientists begin to decipher the data produced by all the telescopes and spacecraft used to observe the DART impact. What we are seeing now are merely hints at what has been learned.

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Webb’s first infrared image of Neptune

9:30 am

Webb's infrared view of Neptune
Click for full image.

The science team for the James Webb Space Telescope today released that telescope’s first infrared image of Neptune.

That image is to the right, cropped and reduced slightly to post here. It is, as the press release touts, the best view in decades of Neptune’s rings. From the caption:

The most prominent features of Neptune’s atmosphere in this image are a series of bright patches in the planet’s southern hemisphere that represent high-altitude methane-ice clouds. More subtly, a thin line of brightness circling the planet’s equator could be a visual signature of global atmospheric circulation that powers Neptune’s winds and storms. Additionally, for the first time, Webb has teased out a continuous band of high-latitude clouds surrounding a previously-known vortex at Neptune’s southern pole.

The dots around the gas giant are the heat signatures of seven of its fourteen moons.

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Webb instrument has technical issue partly preventing its use

9:31 am

Because a an issue with the mid-infrared instrument (MIRI) on the James Webb Space Telescope, the telescope’s engineering team has paused use of that instrument while it reviews the situation.

On Aug. 24, a mechanism that supports one of these modes, known as medium-resolution spectroscopy (MRS), exhibited what appears to be increased friction during setup for a science observation. This mechanism is a grating wheel that allows scientists to select between short, medium, and longer wavelengths when making observations using the MRS mode. Following preliminary health checks and investigations into the issue, an anomaly review board was convened Sept. 6 to assess the best path forward.

The Webb team has paused in scheduling observations using this particular observing mode while they continue to analyze its behavior and are currently developing strategies to resume MRS observations as soon as possible. The observatory is in good health, and MIRI’s other three observing modes – imaging, low-resolution spectroscopy, and coronagraphy – are operating normally and remain available for science observations.

I am quoting almost entirely NASA’s short announcement. The announcement is vague, confusing, and (quite typically) written to minimize the reality of the issue. I can’t figure out how MIRI’s other observing modes are available if they have paused use of a mechanism that allows them to choose modes.

Regardless, Webb is awful young to have this kind of problem.

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Webb takes its first infrared image of Mars

9:12 am

Webb's first infrared image of Mars
Click for full image.

Astronomers have now released the the James Webb Space Telescope’s first infrared image of Mars, taken on September 5, 2022.

The image to the right, cropped and reduced to post here, shows some of the data obtained. Because Mars is so close, it is actually too bright for Webb’s instruments. To get any data, the exposures were very very short, and still the brightest areas — as indicated by large areas of yellow — are overexposed. The cause of the different brightness of Hellas Basin, however, is not simply because the basin — the deepest point on Mars — is cooler.

As light emitted by the planet passes through Mars’ atmosphere, some gets absorbed by carbon dioxide (CO2) molecules. The Hellas Basin – which is the largest well-preserved impact structure on Mars, spanning more than 1,200 miles (2,000 kilometers) – appears darker than the surroundings because of this effect. “This is actually not a thermal effect at Hellas,” explained the principal investigator, Geronimo Villanueva of NASA’s Goddard Space Flight Center, who designed these Webb observations. “The Hellas Basin is a lower altitude, and thus experiences higher air pressure. That higher pressure leads to a suppression of the thermal emission at this particular wavelength range [4.1-4.4 microns] due to an effect called pressure broadening. It will be very interesting to tease apart these competing effects in these data.”

The NASA press release says the scientists are preparing a paper analyzing the spectral data and what it revealed about “dust, icy clouds, what kind of rocks are on the planet’s surface, and the composition of the atmosphere,” I suspect however that Webb’s capabilities for studying Mars are much more limited than implied, and that it will over time take much fewer images of the red planet, compared to Hubble.

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Webb’s infrared view of the Tarantula Nebula

9:55 am

Two views of the Tarantula Nebula by Webb
Click for original image.

The two images to the right, reduced and annotated to post here, were released today by the science team of the James Webb Space Telescope, and show two different views of the Tarantula Nebula, located 161,000 light years away in the Large Magellanic Cloud.

It is home to the hottest, most massive stars known. Astronomers focused three of Webb’s high-resolution infrared instruments on the Tarantula. Viewed with Webb’s Near-Infrared Camera (NIRCam) [top], the region resembles a burrowing tarantula’s home, lined with its silk. The nebula’s cavity centered in the NIRCam image has been hollowed out by blistering radiation from a cluster of massive young stars, which sparkle pale blue in the image. Only the densest surrounding areas of the nebula resist erosion by these stars’ powerful stellar winds, forming pillars that appear to point back toward the cluster. These pillars contain forming protostars, which will eventually emerge from their dusty cocoons and take their turn shaping the nebula.

…The region takes on a different appearance when viewed in the longer infrared wavelengths detected by Webb’s Mid-infrared Instrument (MIRI) [bottom]. The hot stars fade, and the cooler gas and dust glow. Within the stellar nursery clouds, points of light indicate embedded protostars, still gaining mass. While shorter wavelengths of light are absorbed or scattered by dust grains in the nebula, and therefore never reach Webb to be detected, longer mid-infrared wavelengths penetrate that dust, ultimately revealing a previously unseen cosmic environment.

As with all images from Webb, these are false color, as the telescope views the infrared heat produced by stars and galaxies and interstellar clouds, not the optical light our eyes see. Thus, the scientists assign different colors to the range of wavelengths each instrument on Webb captures.

These photos once again illustrate Webb’s value. It will provide a new layer of data to supplement the basic visual information provided by the Hubble Space Telescope, allowing scientists to better understand the puzzles we see in the optical.

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Webb obtains first direct infrared images of exoplanet

9:49 am

Webb's first infrared images of an exoplanet
Click for original image.

Using four different infrared instruments on the James Webb Space Telescope, astronomers have obtained the first infrared images of a gas giant with a mass about six to twelve times larger than Jupiter and circling about 100 times farther from its sun.

The montage to the right shows these four images. The white star marks the location of this star, the light of which was blocked out to make the planet’s dim light visible. The bar shapes on either side of the planet in the NIRCam images are artifacts from the instrument’s optics, not objects surrounding the planet.

This is not the first direct image of an exoplanet, as the Hubble Space Telescope has already done so, and done it in the visible spectrum that humans use to see. However, Webb’s infrared images provide a great deal of additional detail about this planet and its immediate surroundings that optical images would not. For example, the MIRI images appear to show us the outer atmosphere of this gas giant.

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Webb’s infrared view of a face-on spiral galaxy

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M74, as seen by Webb and Hubble combined
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Using the James Webb Space Telescope, astronomers have produced a false-color infrared view of M74, a face-on spiral galaxy located 32 million light years away.

The montage above shows that image to the right, with a Hubble optical image to the left. In the center both images are combined.

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.

Because infrared can see through cold dust, it provides a much sharper view of this galaxy’s central regions.

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Webb detects carbon dioxide in atmosphere of exoplanet

8:42 am

Scientists using the James Webb Space Telescope have detected carbon dioxide in the atmosphere of a hot gas giant exoplanet about 700 light years away.

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. Its extreme puffiness is partly related to its high temperature (about 900° Celsius or 1170 Kelvin). 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 the Hubble and Spitzer space telescopes, revealed the presence of water vapour, 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.

This is only the beginning. Astronomers have told me repeatedly that the most important area of research in astronomy in the next few decades will be the study of known exoplanets and their make-up. Webb is now a new tool in that effort. Combined with other telescopes looking at other wavelengths scientists will be able to identify a whole range of molecules in the atmospheres of these transiting exoplanets. We will begin to get our first glimpse into what other solar systems are like.

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Another Webb infrared image of Jupiter released

8:53 am

Jupiter as seen in the infrared by Webb
Click for original image.

The science team for the James Webb Space Telescope today released another infrared false-color image of Jupiter, this time processed for science instead of calibration of the telescope after launch.

That image is to the right, reduced to post here. From the caption:

Several exposures in three different filters were assembled to create this mosaic, after being corrected for the rotation of the planet. The combination of filters yields an image whose colors denote the height of the clouds and the intensity of auroral emissions.

The F360M filter (mapped to the red-orange colors) is sensitive to light reflected from the lower clouds and upper hazes. The red features in the polar regions are auroral emissions, caused by ions excited through collisions with charged particles at altitudes up to 1000 km above the cloud level. Auroral emission in red is evident in the northern and southern polar regions and reaches high above the limb of the planet. In the F212N filter (mapped to yellow-green colors), the gaseous methane in Jupiter’s atmosphere absorbs light; the greenish areas around the polar regions come from stratospheric hazes 100-200 km above the cloud level. The stratospheric haze that appears green in this composite is also concentrated in the polar regions, but extends down to equatorial latitudes and can also be seen along the limbs (edges) of the planet. The cyan channel holds the F150W2 filter, which is primarily sensitive to reflected light from the Jupiter’s deeper main cloud level at about one bar.

The Great Red Spot, the hazy equatorial region and myriad small storm systems appear white (or reddish-white) in this false-color image. Regions with little cloud cover appear as dark ribbons north of the equatorial region. Some dark regions — for example, those next to the Great Red Spot and in cyclonic features in the southern hemisphere — are also dark-colored when observed in visible wavelengths.

This image is part of the telescope’s early release science program.

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First Webb infrared image of Cartwheel Galaxy

9:13 am

Webb's view of the Cartwheel Galaxy
Click for full image.

Scientists today have released a new infrared image of the Cartwheel Galaxy, taken by two instruments on the James Webb Space Telescope. That image is to the right, reduced to post here. From the caption:

In this near- and mid-infrared composite image, MIRI data are colored red while NIRCam data are colored blue, orange, and yellow. Amidst the red swirls of dust, there are many individual blue dots, which represent individual stars or pockets of star formation. NIRCam also defines the difference between the older star populations and dense dust in the core and the younger star populations outside of it.

The galaxy, located about a half billion light years away, is one of the more well known astronomical objects due to its unusual shape, believed caused by a collision with a smaller galaxy sometime in the past. Earlier this year for example astronomers discovered a supernovae had exploded in the galaxy sometime in 2021. To see a 1995 Hubble optical image, go here.

This Webb image reveals many new details previously obscured by dust.

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Another Webb galaxy found even closer to the Big Bang

9:54 am

A galaxy formed only 250 million years after the universe formed

Using data from the first Webb deep field, astronomers have identified another galaxy in that image that apparently was able to form less than 250 million years after the the Big Bang, the theorized beginning of the universe.

Like the distant galaxies described last week, it also appears to have the equivalent of a billion Suns of material in the form of stars. The researchers estimate that it might have started star formation as early as 120 million years after the Big Bang, and had certainly done so by 220 million years.

You can read the actual research paper here [pdf]. The image of the galaxy to the right is taken from figure 4 of the paper. From its abstract:

We provide details of the 55 high-redshift galaxy candidates, 44 of which are new, that have enabled this new analysis. Our sample contains 6 galaxies at z≥12, one of which appears to set a new redshift record as an apparently robust galaxy candidate at z≃16.7.

The speed in which this galaxy formed places a great challenge on the Big Bang theory itself. 220 million years is an instant when it comes to galaxy formation, which has been assumed to take far longer. Either galaxy formation is a much faster process than expected, or something is seriously wrong with the timing of the Big Bang theory itself.

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The earliest galaxy so far seen?

10:37 am

Earliest galaxy?

Scientists using the James Webb Space Telescope now think they have identified a galaxy formed only 330 million years after the Big Bang.

The red smudge in the centre of this image [to the right] is thought to be a galaxy with a redshift of around z=13, as seen by the NIRCam instrument on the James Webb Space Telescope. This redshift estimate is based on photometry so the object remains a candidate rather than a confirmed high-redshift galaxy, but if confirmed spectroscopically this would be the highest-redshift galaxy yet observed.

You can read the research paper itself here [pdf]. The galaxy is actually very young, and its nature, along with a second also described by the research, appears to contradict expectations. From the paper’s abstract:

These sources, if confirmed, join GNz11 in defying number density forecasts for luminous galaxies based on Schechter UV luminosity functions, which require a survey area > 10× larger than we have
studied here to find such luminous sources at such high redshifts. They extend evidence from lower redshifts for little or no evolution in the bright end of the UV luminosity function into the cosmic dawn epoch, with implications for just how early these galaxies began forming. This, in turn, suggests that future deep JWST observations may identify relatively bright galaxies to much earlier epochs than might have been anticipated. [emphasis mine]

In other words, this early data from Webb suggests that galaxies formed much faster than expected after the Big Bang. This either means all the theories describing the Bang are wrong, or that it might not have even happened.

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