Tag: Webb Space Telescope

Webb detects large water plume released from Saturn’s moon Enceladus

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Water vapor plume seen by Webb
Click for original image.

Using the infrared cameras on the Webb Space Telescope, astronomers have detected a surprisingly long and large plume of water vapor erupting from the tiger stripe fractures on Saturn’s moon Enceladus that scientists for years have detected vapor plumes.

The false color image to the right shows that plume.

A water vapor plume from Saturn’s moon Enceladus spanning more than 6,000 miles – nearly the distance from Los Angeles, California to Buenos Aires, Argentina – has been detected by researchers using NASA’s James Webb Space Telescope. Not only is this the first time such a water emission has been seen over such an expansive distance, but Webb is also giving scientists a direct look, for the first time, at how this emission feeds the water supply for the entire system of Saturn and its rings.

…The length of the plume was not the only characteristic that intrigued researchers. The rate at which the water vapor is gushing out, about 79 gallons per second, is also particularly impressive. At this rate, you could fill an Olympic-sized swimming pool in just a couple of hours. In comparison, doing so with a garden hose on Earth would take more than 2 weeks.

Though that rate of release sounds large, we must remember it is being released from a moon 313 miles across. From that perspective the rate of flow is quite reasonable.

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Webb and Chandra take composite X-ray/infrared images of four famous objects

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Composite Chandra/Webb image of M16
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Astronomers have now used the Chandra X-ray Observatory and Webb Space Telescope (working in the infrared) to produce spectacular composite false-color X-ray/infrared images of four famous heavenly objects.

To the right is the composite taken of the Eagle Nebula, also known as Messier 16. It was also dubbed the Pillars of Creation when it was one of the first Hubble images taken after the telescope’s mirror focus was fixed in 1993. From the caption:

The Webb image shows the dark columns of gas and dust shrouding the few remaining fledgling stars just being formed. The Chandra sources, which look like dots, are young stars that give off copious amounts of X-rays. (X-ray: red, blue; infrared: red, green, blue)

The other images include star cluster NGC 346 in a nearby galaxy, the spiral galaxy NGC 1672, and the face-on spiral galaxy Messier 74.

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Webb takes infrared image of the disk of dust and debris surrounding Fomalhaut

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Fomalhaut debris disk as seen in the infrared by Webb
Click for original image.

Using the mid-infrared instrument on the Webb Space Telescope, astronomers have obtained a new high resolution infrared image of the disk of dust and debris that surrounds the star Fomalhaut, and (surprise!) have it to be more complex than they previously believed.

That image is to the right, annotated by the science team.

Overall, there are three nested belts extending out to 14 billion miles (23 billion kilometers) from the star; that’s 150 times the distance of Earth from the Sun. The scale of the outermost belt is roughly twice the scale of our solar system’s Kuiper Belt of small bodies and cold dust beyond Neptune. The inner belts – which had never been seen before – were revealed by Webb for the first time.

The dust cloud identified in the outer ring is possibly left over from a recent collusion of larger bodies.

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Webb snaps infrared picture of Uranus

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Uranus as seen in the infrared by Webb
Click for original Webb false-color image.

In a follow-up to a recent Hubble Space Telescope optical image of Uranus, scientists have now used the Webb Space Telescope to take a comparable picture in the infrared of the gas giant.

Both pictures are to the right, with the Webb picture at the top including the scientists’ annotations.

On the right side of the planet there’s an area of brightening at the pole facing the Sun, known as a polar cap. This polar cap is unique to Uranus – it seems to appear when the pole enters direct sunlight in the summer and vanish in the fall; these Webb data will help scientists understand the currently mysterious mechanism. Webb revealed a surprising aspect of the polar cap: a subtle enhanced brightening at the center of the cap. The sensitivity and longer wavelengths of Webb’s NIRCam may be why we can see this enhanced Uranus polar feature when it has not been seen as clearly with other powerful telescopes like the Hubble Space Telescope and Keck Observatory.

At the edge of the polar cap lies a bright cloud as well as a few fainter extended features just beyond the cap’s edge, and a second very bright cloud is seen at the planet’s left limb. Such clouds are typical for Uranus in infrared wavelengths, and likely are connected to storm activity.

The Webb image also captures 11 of Uranus’s 13 rings, which appear much brighter in the infrared than in the optical.

Unlike all other planets in the solar system, Uranus’s rotation is tilted so much that it actually rolls as it orbits the Sun, a motion that is obvious by comparing these pictures with Hubble’s 2014 optical picture.

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Webb finds Earth-sized exoplanet likely too hot to have atmosphere

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The uncertainty of science: Using the infrared Webb Space Telescope, scientists have measured the temperature of the Earth-sized exoplanet, dubbed Trappist-1b, and found its temperature is probably too hot to have atmosphere.

The red dwarf star Trappist-1is about 40 light years from Earth, and in 2017 was found to have a solar system of seven exoplanets, all rocky terrestrial planets like the inner planets of our solar system. Trappist-1b is the innermost exoplanet. To measure its temperature, Webb observed the star while the planet was eclipsed by the star as well as when it was not, and measured the tiny difference in infrared light.

The team analyzed data from five separate secondary eclipse observations. “We compared the results to computer models showing what the temperature should be in different scenarios,” explained Ducrot. “The results are almost perfectly consistent with a blackbody made of bare rock and no atmosphere to circulate the heat. We also didn’t see any signs of light being absorbed by carbon dioxide, which would be apparent in these measurements.”

As this was the innermost of the star’s solar system, it is also the one most likely to lack an atmosphere. Webb’s observations of the system continue, so there is a chance that data about the other exoplanets will eventually tell us more about them.

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Webb detects “hot sand clouds” in atmosphere of exoplanet

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Using the Webb Space Telescope, astronomers have detected “hot sand clouds” in atmosphere of exoplanet 40 light years away, along with evidence of water, methane, carbon monoxide, carbon dioxide, sodium, and potassium.

You can read the paper here [pdf]. The exoplanet itself appears to have some features that resemble that of a brown dwarf, or failed star, instead of an exoplanet.

Although VHS 1256 b is more on the heavier side of the known exoplanets, its gravity is relatively low compared to more massive brown dwarfs. Such very low-mass stars can only burn deuterium for a relatively short duration. Consequently, the planet’s silicate clouds can appear and remain higher in its atmosphere, where the JWST can detect them. Another reason its skies are so turbulent is the planet’s age. In astronomical terms, it is pretty young. Only 150 million years have passed since it formed. The planet’s heat stems from the recent formation process – and it will continue to change and cool over billions of years.

The sand clouds are hot, in the range of 1,500 degrees Fahrenheit.

These results were obtained as part of an early-release program from Webb, and illustrate the potential of the infrared space telescope for learning many specific details about brown dwarfs and exoplanets.

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Webb finds another galaxy in early universe that should not exist

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The uncertainty of science: Scientists using the Webb Space Telescope have identified another galaxy about 12 billion light years away and only about 1.7 billion years after the theorized Big Bang that is too rich in chemicals as well as too active in star formation to have had time to form.

SPT0418-SE is believed to have already hosted multiple generations of stars, despite its young age. Both of the galaxies have a mature metallicity — or large amounts of elements like carbon, oxygen and nitrogen that are heavier than hydrogen and helium — which is similar to the sun. However, our sun is 4.5 billion years old and inherited most of its metals from previous generations of stars that were eight billion years old, the researchers said.

In other words, this galaxy somehow obtained complex elements in only 1.7 billion years that in our galaxy took twelve billion years, something that defies all theories of galactic and stellar evolution. Either the Big Bang did not happen when it did, or all theories about the growth and development of galaxies are wrong.

One could reasonably argue that this particular observation might be mistaken, except that it is not the only one from Webb that shows similar data. Webb’s infrared data is challenging the fundamentals of all cosmology, developed by theorists over the past half century.

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Webb spots massive galaxies in the early universe that should not exist at that time

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The uncertainty of science: Astronomers using the Webb Space Telescope have identified six galaxies that are far too massive and evolved to have formed so quickly after the Big Bang.

The research, published today in Nature, could upend our model of the Universe and force a drastic rethink of how the first galaxies formed after the Big Bang. “We’ve never observed galaxies of this colossal size, this early on after the Big Bang,” says lead researcher Associate Professor Ivo Labbé from Swinburne University of Technology.

“The six galaxies we found are more than 12 billion years old, only 500 to 700 million years after the Big Bang, reaching sizes up to 100 billion times the mass of our sun. This is too big to even exist within current models.

You can read the paper here [pdf]. The “current models” Labbé is referring to are all the present theories and data that say the Big Bang occurred 13.7 billion years ago. These galaxies, however, found less than a billion years after that event, would have needed 12 billion years to have accumulated their mass.

If confirmed, these galaxies essentially tell us that the Big Bang is wrong, or very very VERY incomplete, and that all the data found that dates its occurrence 13.7 billion years ago, based on the Hubble constant, must be reanalyzed.

It is also possible these galaxies are actually not galaxies, but a new kind of supermassive black hole able to form very quickly. Expect many scientists who are heavily invested in the Big Bang to push for this explanation. It might be true, but their biases are true also, which means that Webb is presenting us with new data that calls for strong skepticism of all conclusions, across the board.

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A galaxy’s structure of gas and dust, as seen in the infrared by Webb

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NGC 1433 as seen in the infrared
NGC 1433 as seen in the infrared. Click for original image.

Scientists have now released 21 papers on the gas and dust structures in nearby galaxies, based on infrared images from the Webb Space Telescope, used in collaboration with other telescopes looking in other wavelengths.

The largest survey of nearby galaxies in Webb’s first year of science operations is being carried out by the Physics at High Angular resolution in Nearby Galaxies (PHANGS) collaboration, involving more than 100 researchers from around the globe. The Webb observations are led by Janice Lee, Gemini Observatory chief scientist at the National Science Foundation’s NOIRLab and affiliate astronomer at the University of Arizona in Tucson.

The team is studying a diverse sample of 19 spiral galaxies, and in Webb’s first few months of science operations, observations of five of those targets – M74, NGC 7496, IC 5332, NGC 1365, and NGC 1433 – have taken place.

The image to the right is Webb’s infrared image of NGC 1433, estimated to be 46 million light years away. The bright areas extending outward in the spiral arms are believed to be star-forming regions. From the caption:

At the center of the galaxy, a tight, bright core featuring a unique double ring structure shines in exquisite detail with Webb’s extreme resolution. In this case, that ‘double ring’ is actually tightly wrapped spiral arms that wind into an oval shape along the galaxy’s bar.

NGC 1433 is a Seyfert galaxy, which are typically relatively close to Earth and has a supermassive black hole at the center eating material at a high rate. The brightness and lack of dust in the MIRI image of NGC 1433 could hint at a recent collision with another galaxy.

When comparing Webb’s infrared view with Hubble’s optical view, taken in 2014 and found here, the differences are definitely striking. Webb sees the gas and dust that is dark in Hubble’s images, while Hubble sees things at much higher resolution and thus sees more fine detail.

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Galaxies without end

9:57 am

Webb infrared image of galaxies without end
Click for original image.

Cool image time! The mid-infrared picture to the right, cropped, reduced, and sharpened to post here, was taken by the Webb Space Telescope during its commissioning process last year shortly after launch, and was used to calibrate the Near-InfraRed Imager and Slitless Spectrograph (NIRISS) instrument, the very same instrument that for the past two weeks was not in operation because a cosmic ray had scrambled its software, requiring a reboot to fix it. From the caption:

The large spiral galaxy at the base of this image is accompanied by a profusion of smaller, more distant galaxies which range from fully-fledged spirals to mere bright smudges. Named LEDA 2046648, it is situated a little over a billion light-years from Earth, in the constellation Hercules.

While the large spiral is majestic, the tiny galaxy smudges are actually more important. Astronomers are right now scrambling to determine their distance and age in order to better understand what the universe was like, thirteen-plus billion years ago. So far the Webb data of these very early galaxies suggests that in this early universe there were many more fully formed galaxies, similar to ones we see in our time, than any theory of the Big Bang had predicted.

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Webb instrument back in operation

9:13 am

Engineers have returned NIRISS, the near infrared spectrograph instrument on the Webb Space Telescope, to full operation after rebooting its software and determining the cause of the problem.

On Jan. 15, NASA’s James Webb Space Telescope’s Near Infrared Imager and Slitless Spectrograph (NIRISS) experienced a communications delay within the science instrument, causing its flight software to time out. Following a full investigation by NASA and Canadian Space Agency (CSA) teams, the cause was determined to likely be a galactic cosmic ray, a form of high-energy radiation from outside our solar system that can sometimes disrupt electrical systems. Encountering cosmic rays is a normal and expected part of operating any spacecraft. This cosmic ray event affected logic in the solid-state circuitry of NIRISS electronics known as the Field Programmable Gate Array. Webb engineers determined that rebooting the instrument would bring it back to full functionality.

After completing the reboot, NIRISS telemetry data demonstrated normal timing, and to fully confirm, the team scheduled a test observation. On Jan. 28, the Webb team sent commands to the instrument to perform the observation, and the results confirmed on Jan. 30 NIRISS is back to full scientific operations.

Engineers actually have a name for such cosmic ray incidents that effect software. They call it a bitflip.

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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”

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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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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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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

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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

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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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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

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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

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Webb and Hubble together look at DART impact of Dimorphus
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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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