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James Webb Space Telescope news

Canada's NIRISS reveals steamy atmosphere of distant planet in detail

A transmission spectrum made from a single observation using Webb's Near-Infrared Imager and Slitless Spectrograph (NIRISS)
Text version - Hot gas giant exploplanet WASP-96 b - Atmosphere composition

A transmission spectrum made from a single observation using Webb's Near-Infrared Imager and Slitless Spectrograph (NIRISS) reveals atmospheric characteristics of the hot gas giant exoplanet WASP-96 b.  

A transmission spectrum is made by comparing starlight filtered through a planet's atmosphere as it moves across the star, to the unfiltered starlight detected when the planet is beside the star.  Each of the 141 data points (white circles) on this graph represents the amount of a specific wavelength of light that is blocked by the planet and absorbed by its atmosphere. 

In this observation, the wavelengths detected by NIRISS range from 0.6 microns (red) to 2.8 microns (in the near-infrared). The amount of starlight blocked ranges from about 13,600 parts per million (1.36 percent) to 14,700 parts per million (1.47 percent).

Researchers are able to detect and measure the abundances of key gases in a planet's atmosphere based on the absorption pattern—the locations and heights of peaks on the graph: each gas has a characteristic set of wavelengths that it absorbs. The temperature of the atmosphere can be calculated based in part on the height of the peaks: a hotter planet has taller peaks. Other characteristics, like the presence of haze and clouds, can be inferred based on the overall shape of different portions of the spectrum.  

The gray lines extending above and below each data point are error bars that show the uncertainty of each measurement, or the reasonable range of actual possible values. For a single observation, the error on these measurements is remarkably small.

The blue line is a best-fit model that takes into account the data, the known properties of WASP-96 b and its star (e.g., size, mass, temperature), and assumed characteristics of the atmosphere. Researchers can vary the parameters in the model – changing unknown characteristics like cloud height in the atmosphere and abundances of various gases – to get a better fit and further understand what the atmosphere is really like. The difference between the best-fit model shown here and the data simply reflects the additional work to be done in analyzing and interpreting the data and the planet. 

Although full analysis of the spectrum will take additional time, it is possible to draw a number of preliminary conclusions. The labeled peaks in the spectrum indicate the presence of water vapor. The height of the water peaks, which is less than expected based on previous observations, is evidence for the presence of clouds that suppress the water vapor features. The gradual downward slope of the left side of the spectrum (shorter wavelengths) is indicative of possible haze. The height of the peaks along with other characteristics of the spectrum is used to calculate an atmospheric temperature of about 1350°F (725°C).  

This is the most detailed infrared exoplanet transmission spectrum ever collected, the first transmission spectrum that includes wavelengths longer than 1.6 microns at such high resolution and accuracy, and the first to cover the entire wavelength range from 0.6 microns (visible red light) to 2.8 microns (near-infrared) in a single shot. The speed with which researchers have been able to make confident interpretations of the spectrum is further testament to the quality of the data. 

The observation was made using NIRISS's Single-Object Slitless Spectroscopy (SOSS) mode, which involves capturing the spectrum of a single bright object, like the star WASP-96, in a field of view. 

WASP-96 b is a hot gas giant exoplanet that orbits a Sun-like star roughly 1,150 light years away, in the constellation Phoenix. The planet orbits extremely close to its star (less than 1/20th the distance between Earth and the Sun) and completes one orbit in less than 3 and a half Earth-days. The planet's discovery, based on ground-based observations, was announced in . The star, WASP-96, is somewhat older than the Sun, but is about the same size, mass, temperature, and colour.

The background illustration of WASP-96 b and its star is based on current understanding of the planet from both NIRISS spectroscopy and previous ground- and space-based observations. Webb has not captured a direct image of the planet or its atmosphere.

NIRISS was contributed by the Canadian Space Agency. The instrument was designed and built by Honeywell in collaboration with the Université de Montréal and the National Research Council Canada.

Credit: NASA/ESA/CSA/STScI

The James Webb Space Telescope has captured the distinct signature of water, along with evidence for clouds and haze, in the atmosphere surrounding a hot, puffy gas giant planet orbiting a distant Sun-like star.

The observation, which reveals the presence of specific gas molecules based on tiny decreases in the brightness of precise colors of light, is the most detailed of its kind to date, demonstrating Webb's unprecedented ability to analyze atmospheres hundreds of light-years away.

While the Hubble Space Telescope has analyzed numerous exoplanet atmospheres over the past two decades, capturing the first clear detection of water in , Webb's immediate and more detailed observation marks a giant leap forward in the quest to characterize potentially habitable planets beyond Earth.

WASP-96 b is one of more than 5,000 confirmed exoplanets in the Milky Way. Located roughly 1,150 light-years away in the southern-sky constellation Phoenix, it represents a type of gas giant that has no direct analog in our solar system. With a mass less than half that of Jupiter and a diameter 1.2 times greater, WASP-96 b is much puffier than any planet orbiting our Sun. And with a temperature greater than 1000°F (538 °C), it is significantly hotter. WASP-96 b orbits extremely close to its Sun-like star, just one-ninth of the distance between Mercury and the Sun, completing one circuit every 3½ Earth-days.

The combination of large size, short orbital period, puffy atmosphere, and lack of contaminating light from objects nearby in the sky makes WASP-96 b an ideal target for atmospheric observations.

On , Webb's Near-Infrared Imager and Slitless Spectrograph (NIRISS) measured light from the WASP-96 system for 6.4 hours as the planet moved across the star. The result is a light curve showing the overall dimming of starlight during the transit, and a transmission spectrum revealing the brightness change of individual wavelengths of infrared light between 0.6 and 2.8 microns.

While the light curve confirms properties of the planet that had already been determined from other observations – the existence, size, and orbit of the planet – the transmission spectrum reveals previously hidden details of the atmosphere: the unambiguous signature of water, indications of haze, and evidence of clouds that were thought not to exist based on prior observations.

The transmission spectrum reveals previously hidden details of the atmosphere
Text version - Hot gas giant exploplanet WASP-96 b - Transit light curve

A light curve from Webb's NIRISS shows the change in brightness of light from the WASP-96 star system over time as the planet transits the star. A transit occurs when an orbiting planet moves between the star and the telescope, blocking some of the light from the star. This observation was made using NIRISS's Single-Object Slitless Spectroscopy (SOSS) mode, which involves capturing the spectrum of a single bright object, like the star WASP-96, in a field of view. 

To capture these data, Webb stared at the WASP-96 star system for 6 hours 23 minutes, beginning about 2.5 hours before the transit and ending about 1.5 hours after the transit was complete. The transit itself lasted for just under 2.5 hours. The curve includes a total of 280 individual brightness measurements – one every 1.4 minutes.

Because the observation was made using a spectrograph, which spreads the light out into hundreds of individual wavelengths, each of the 280 points on the graph represents the combined brightness of thousands of wavelengths of infrared light.

The actual dimming caused by the planet is extremely small: The difference between the brightest and dimmest points is less than 1.5 percent. NIRISS is ideally suited for this observation because it has the ability to observe relatively bright targets over time, along with the sensitivity needed to measure such small differences in brightness: In this observation, the instrument was able to measure differences in brightness as small as 0.02 percent.

Although the presence, size, mass, and orbit of the planet had already been determined based on previous transit observations, this transit light curve can be used to confirm and refine existing measurements, such as the planet's diameter, the timing of the transit, and the planet's orbital properties. 

WASP-96 b is a hot gas giant exoplanet that orbits a Sun-like star roughly 1,150 light years away, in the constellation Phoenix. The planet orbits extremely close to its star (less than 1/20th the distance between Earth and the Sun) and completes one orbit in less than 3 and a half Earth-days. The planet's discovery, from ground-based observations, was announced in 2014. 

The background illustration of WASP-96 b and its Sun-like star is based on current understanding of the planet from both NIRISS spectroscopy and previous ground- and space-based observations. Webb has not captured a direct image of the planet or its atmosphere.

NIRISS was contributed by the Canadian Space Agency. The instrument was designed and built by Honeywell in collaboration with the Université de Montréal and the National Research Council Canada.

Credit: NASA/ESA/CSA/STScI

A transmission spectrum is made by comparing starlight filtered through a planet's atmosphere as it moves across the star to the unfiltered starlight detected when the planet is beside the star. Researchers are able to detect and measure the abundances of key gases in a planet's atmosphere based on the absorption pattern – the locations and heights of peaks on the graph. In the same way that people have distinctive fingerprints and DNA sequences, atoms and molecules have characteristic patterns of wavelengths that they absorb.

The spectrum of WASP-96 b captured by NIRISS is not only the most detailed near-infrared transmission spectrum of an exoplanet atmosphere captured to date, but it also covers a remarkably wide range of wavelengths, including visible red light and a portion of the spectrum that has not previously been accessible from other telescopes (wavelengths longer than 1.6 microns). This part of the spectrum is particularly sensitive to water as well as other key molecules like oxygen, methane, and carbon dioxide, which are not immediately obvious in the WASP-96 b spectrum but which should be detectable in other exoplanets planned for observation by Webb.

Researchers will be able to use the spectrum to measure the amount of water vapour in the atmosphere, constrain the abundance of various elements like carbon and oxygen, and estimate the temperature of the atmosphere with depth. They can then use this information to make inferences about the overall make-up of the planet, as well as how, when, and where it formed. The blue line on the graph is a best-fit model that takes into account the data, the known properties of WASP-96 b and its star (e.g., size, mass, temperature), and assumed characteristics of the atmosphere.

The exceptional detail and clarity of these measurements is possible because of Webb's state-of-the-art design. Its 270-square-foot (25 ) gold-coated mirror collects infrared light efficiently. Its precision spectrographs spread light out into rainbows of thousands of infrared colours. And its sensitive infrared detectors measure extremely subtle differences in brightness. NIRISS is able to detect colour differences of only about one thousandth of a micron (the difference between green and yellow is about 50 thousandths of a micron), and differences in the brightness between those colours of a few hundred parts per million.

In addition, Webb's extreme stability and its orbital location around Lagrange Point 2 roughly a million miles (environ 1 500 000 km) away from the contaminating effects of Earth's atmosphere makes for an uninterrupted view and clean data that can be analyzed relatively quickly.

The extraordinarily detailed spectrum – made by simultaneously analyzing 280 individual spectra captured over the observation – provides just a hint of what Webb has in store for exoplanet research. Over the coming year, researchers will use spectroscopy to analyze the surfaces and atmospheres of several dozen exoplanets, from small rocky planets to gas- and ice-rich giants. Nearly one-quarter of Webb's Cycle 1 observation time is allocated to studying exoplanets and the materials that form them.

This NIRISS observation demonstrates that Webb has the power to characterize the atmospheres of exoplanets — including those of potentially habitable planets — in exquisite detail.

The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.

NIRISS was contributed by the Canadian Space Agency. The instrument was designed and built by Honeywell in collaboration with the Université de Montréal and the National Research Council Canada.

Abridged text reprinted courtesy of NASA

NASA shares list of cosmic targets for Webb Telescope's first science images

Credits: NASA, STScI

NASA's James Webb Space Telescope, a partnership with the European Space Agency (ESA) and the Canadian Space Agency (CSA), will soon reveal unprecedented and detailed views of the universe, with the upcoming release of its first full-colour science images and spectroscopic data.

Below is the list of cosmic objects that Webb targeted for these first observations, which will be released in NASA's live broadcast beginning at 10:30 a.m. ET on Tuesday, . The event will also be broadcast via the CSA's YouTube and Facebook pages.

These targets represent the first wave of full-colour science images and spectra the observatory has gathered, and the official beginning of Webb's general science operations. They were selected by an international committee of representatives from NASA, ESA, the CSA, and the Space Telescope Science Institute.

  • Carina Nebula. The Carina Nebula is one of the largest and brightest nebulae in the sky, located approximately 7,600 light-years away in the southern constellation Carina. Nebulae are stellar nurseries where stars form. The Carina Nebula is home to many massive stars, several times larger than the Sun.
  • WASP-96 b (spectrum). WASP-96 b is a giant planet outside our solar system, composed mainly of gas. The planet, located nearly 1,150 light-years from Earth, orbits its star every 3.4 days. It has about half the mass of Jupiter, and its discovery was announced in .
  • Southern Ring Nebula. The Southern Ring, or "Eight-Burst" Nebula, is a planetary nebula – an expanding cloud of gas, surrounding a dying star. It is nearly half a light-year in diameter and is located approximately 2,000 light-years away from Earth.
  • Stephan's Quintet: About 290 million light-years away, Stephan's Quintet is located in the constellation Pegasus. It is notable for being the first compact galaxy group ever discovered. Four of the five galaxies within the quintet are locked in a cosmic dance of repeated close encounters.
  • SMACS 0723: Massive foreground galaxy clusters magnify and distort the light of objects behind them, permitting a deep-field view into both the extremely distant and intrinsically faint galaxy populations.

The release of these first science images marks the official beginning of Webb's science operations, which will continue to explore the mission's key science themes.

The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it.

Abridged text reprinted courtesy of NASA

Webb's Fine Guidance Sensor provides a preview

This Fine Guidance Sensor test image was acquired in parallel with NIRCam imaging of the star HD147980 over a period of eight days at the beginning of May. This engineering image represents a total of 32 hours of exposure time at several overlapping pointings of the Guider 2 channel. The observations were not optimized for detection of faint objects, but nevertheless the image captures extremely faint objects and is, for now, the deepest image of the infrared sky. The unfiltered wavelength response of the guider, from 0.6 to 5 micrometers, helps provide this extreme sensitivity. The image is mono-chromatic and is displayed in false color with white-yellow-orange-red representing the progression from brightest to dimmest. The bright star (at 9.3 magnitude) on the right hand edge is 2MASS 16235798+2826079. There are only a handful of stars in this image – distinguished by their diffraction spikes. The rest of the objects are thousands of faint galaxies, some in the nearby universe, but many, many more in the high redshift universe. (Credits: NASA, CSA, FGS team)

Webb's Fine Guidance Sensor (FGS) – developed by the Canadian Space Agency (CSA) and designed to find and lock onto cosmic targets – recently captured a view of stars and galaxies that provides a tantalizing glimpse at what the telescope's science instruments will reveal in the coming weeks, months, and years.

FGS has always been capable of capturing imagery, but its primary purpose is to enable accurate science measurements and imaging with precision pointing. When it does capture imagery, the imagery is typically not kept: Given the limited communications bandwidth between L2 and Earth, Webb only sends data from up to two science instruments at a time. But during a week-long stability test in , it occurred to the team that they could keep the imagery that was being captured because there was available data transfer bandwidth.

The resulting engineering test image has some rough-around-the-edges qualities to it. It was not optimized to be a science observation; rather, the data was taken to test how well the telescope could stay locked onto a target, but it does hint at the power of the telescope. It carries a few hallmarks of the views Webb has produced during its postlaunch preparations. Bright stars stand out with their six long, sharply defined diffraction spikes – an effect due to Webb's six-sided mirror segments. Beyond the stars, galaxies fill nearly the entire background.

The result – using 72 exposures over 32 hours – is among the deepest images of the universe ever taken, according to Webb scientists. When the FGS's aperture is open, it is not using colour filters like the other science instruments, meaning it is impossible to study the age of the galaxies in this image with the rigour needed for scientific analysis. But even when capturing unplanned imagery during a test, Webb is capable of producing stunning views of the cosmos.

"With the Webb telescope achieving better-than-expected image quality, early in commissioning we intentionally defocused the guiders by a small amount to help ensure they met their performance requirements. When this image was taken, I was thrilled to clearly see all the detailed structure in these faint galaxies. Given what we now know is possible with deep broad-band guider images, perhaps such images, taken in parallel with other observations where feasible, could prove scientifically useful in the future," said Neil Rowlands, program scientist for Webb's Fine Guidance Sensor, at Honeywell Aerospace.

The FGS image is coloured using a reddish colour scheme that has been used for Webb's other engineering images throughout commissioning. In addition, there was no "dithering" during these exposures. Dithering is when the telescope repositions slightly between each exposure. In addition, the centres of bright stars appear black because they saturate Webb's detectors, and the pointing of the telescope didn't change over the exposures to capture the centre from different pixels within the camera's detectors. The overlapping frames of the different exposures can also be seen at the image's edges and corners.

In this engineering test, the purpose was to lock on to one star and test how well Webb could control its "roll"– literally, Webb's ability to roll to one side like an aircraft in flight. That test was performed successfully – in addition to producing an image that sparks the imagination of scientists who will be analyzing Webb's science data.

While Webb's four science instruments will ultimately reveal the telescope's new view of the universe, the FGS is the one element that will be used in every single Webb observation over the course of the mission's lifetime. It has already played a crucial role in aligning Webb's optics. Now, during the first real science observations made in June and once science operations begin in mid-July, it will guide each Webb observation to its target and maintain the precision necessary for Webb to produce breakthrough discoveries about stars, exoplanets, galaxies, and even moving targets within our solar system.

Abridged text reprinted courtesy of NASA

Canada's NIRISS ready to see cosmos in over 2000 infrared colours

Canada's NIRISS instrument ready to disperse starlight

Test detector image of the NIRISS instrument operated in its SOSS mode while pointing at a bright star. Each colour seen in the image corresponds to a specific infrared wavelength between 0.6 and 2.8 microns. The black lines seen on the spectra are the telltale signature of hydrogen atoms present in the star. NIRISS is a contribution from the Canadian Space Agency to the Webb project that provides unique observational capabilities that complement its other onboard instruments. (Credit: NASA, CSA, and NIRISS team/Loïc Albert/University of Montreal)

One of the James Webb Space Telescope's four primary scientific instruments known as the Near-Infrared Imager and Slitless Spectrograph (NIRISS), provided by the Canadian Space Agency, has concluded its post-launch preparations and is now ready for science.

The last NIRISS mode to be checked off before the instrument was declared ready to begin scientific operations was the single-object slitless spectroscopy (SOSS) capability. The heart of the SOSS mode is a specialized prism assembly that disperses the light of a star to create three distinctive spectra (rainbows), revealing the hues of more than 2000 infrared colours collected simultaneously in a single observation. This mode will be specifically used to probe the atmospheres of transiting exoplanets, i.e. planets that happen to eclipse their star periodically, dimming the star's brightness for a period of time. By comparing the spectra collected during and before or after a transit event with great precision, one can determine not only whether or not the exoplanet has an atmosphere, but also what atoms and molecules are in it.

With NIRISS post-launch commissioning activities concluded, the Webb team will continue to focus on checking off the five remaining modes on its other instruments. NASA's James Webb Space Telescope, a partnership with the European Space Agency and the Canadian Space Agency, will release its first full-colour images and spectroscopic data on .

Abridged text reprinted courtesy of NASA

First images from the James Webb Space Telescope coming soon

Artist conception of the James Webb Space Telescope

Artist conception of the James Webb Space Telescope. (Credit: NASA)

The James Webb Space Telescope will release its first full-colour images and spectroscopic data on . The official release of images and data will showcase Webb's full science capabilities.

Deciding what Webb should look at first has been a project more than five years in the making, undertaken by an international partnership between NASA, ESA (European Space Agency), the Canadian Space Agency (CSA), and the Space Telescope Science Institute in Baltimore, home to Webb's science and mission operations.

Once each of Webb's instruments, including CSA's Near-Infrared Imager and Slitless Spectrograph (NIRISS), has been calibrated, tested, and given the green light by its science and engineering teams, the first images and spectroscopic observations will be made. These experts will proceed through a list of targets and then the production team will receive the data from Webb's instrument scientists and process it into images for astronomers and the public.

In addition to imagery, Webb will be capturing spectroscopic data – detailed information astronomers can read in light. The first images package of materials will highlight the science themes that inspired the mission and will be the focus of its work: the early universe, the evolution of galaxies through time, the lifecycle of stars, and other worlds. All of Webb's commissioning data – the data taken while aligning the telescope and preparing the instruments – will also be made publicly available.

After capturing its first images, Webb's scientific observations will begin. Canadian scientists will be some of the first to use the James Webb Space Telescope to make new discoveries about the universe. Teams have already applied through a competitive process for time to use the telescope, in what astronomers call its first "cycle," or first year of observations. These observations will mark the official beginning of Webb's general science operations.

The James Webb Space Telescope is the world's premier space science observatory. Webb will solve mysteries in our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA and the CSA.

Abridged text is reprinted courtesy of NASA

Webb Telescope in full focus, ready for instrument commissioning

Webb telescope image sharpness check (with details) for NIRSpec, NIRCam, MIRI, the fine guidance sensor and NIRISS

Credit: NASA/STScI

Alignment of the James Webb Space Telescope is now complete. After full review, the observatory has been confirmed to be capable of capturing crisp, well-focused images with each of its four powerful onboard science instruments, including the Canadian Space Agency's NIRISS. Webb is ready to move forward into its next and final series of preparations, known as science instrument commissioning. This process of setting up and testing the instruments will take about two months before scientific operations begin in the summer.

The alignment of the telescope across all of Webb's instruments can be seen in a series of images that captures the observatory's full field of view.

Webb's mirrors are now directing fully focused light collected from space down into each instrument, and each instrument is successfully capturing images with the light being delivered to them. The image quality delivered to all instruments is as good as physically possible, given the size of the telescope.

Webb Telescope - Image sharpness check

Engineering images of sharply focused stars in the field of view of each instrument demonstrate that the telescope is fully aligned and in focus. For this test, Webb pointed at part of the Large Magellanic Cloud, a small satellite galaxy of the Milky Way, providing a dense field of hundreds of thousands of stars across all the observatory's sensors. The sizes and positions of the images shown here depict the relative arrangement of each of Webb's instruments in the telescope's focal plane, each pointing at a slightly offset part of the sky relative to one another. Webb's three imaging instruments are NIRCam (images shown here at a wavelength of 2 microns), NIRISS (image shown here at 1.5 microns), and MIRI (shown at 7.7 microns, a longer wavelength revealing emission from interstellar clouds as well as starlight). NIRSpec is a spectrograph rather than an imager but can take images, such as the 1.1 micron image shown here, for calibrations and target acquisition. The dark regions visible in parts of the NIRSpec data are due to structures of its microshutter array, which has several hundred thousand controllable shutters that can be opened or shut to select which light is sent into the spectrograph. Lastly, Webb's Fine Guidance Sensor, provided by the Canadian Space Agency, tracks guide stars to point the observatory accurately and precisely; its two sensors are not generally used for scientific imaging but can take calibration images such as those shown here. This image data is used not just to assess image sharpness but also to precisely measure and calibrate subtle image distortions and alignments between sensors as part of Webb's overall instrument calibration process. (Credit: NASA/STScI)

Now, the Webb team will turn its attention to science instrument commissioning. Each instrument is a highly sophisticated set of detectors equipped with unique lenses, masks, filters, and customized equipment that helps it perform the science it was designed to achieve. The specialized characteristics of these instruments will be configured and operated in various combinations during the instrument commissioning phase to fully confirm their readiness for science. 

As part of scientific instrument commissioning, the telescope will be commanded to point to different areas in the sky where the total amount of solar radiation hitting the observatory will vary to confirm thermal stability when changing targets. Furthermore, ongoing maintenance observations every two days will monitor the mirror alignment and, when needed, apply corrections to keep the mirrors in their aligned locations.  

Abridged text is reprinted courtesy of NASA

Webb reaches alignment milestone, optics working successfully

Webb - Telescope alignment evaluation image

While the purpose of this image was to focus on the bright star at the center for alignment evaluation, Webb's optics and NIRCam are so sensitive that the galaxies and stars seen in the background show up. At this stage of Webb's mirror alignment, known as "fine phasing," each of the primary mirror segments have been adjusted to produce one unified image of the same star using only the NIRCam instrument. This image of the star, which is called 2MASS J17554042+6551277, uses a red filter to optimize visual contrast. (Credit: NASA/STScI)

On , assisted by the Canadian Space Agency's Fine Guidance Sensor, the Webb team completed the stage of mirror alignment known as "fine phasing." At this key stage in the commissioning of Webb's Optical Telescope Element, every optical parameter that has been checked and tested is performing at, or above, expectations. The observatory is able to successfully gather light from distant objects and deliver it to its instruments without issue.

Although there are months to go before Webb ultimately delivers its new view of the cosmos, achieving this milestone means the team is confident that Webb's first-of-its-kind optical system is working as well as possible.

With the fine phasing stage of telescope alignment completed, the team has now fully aligned Webb's primary imager, the Near-Infrared Camera, with the observatory's mirrors.

Over the next six weeks, the team will proceed through the next of several remaining alignment steps before final science instrument preparations. The team will further align the telescope to include the Near-Infrared Spectrograph, the Mid-Infrared Instrument, and the Canadian-built Near Infrared Imager and Slitless Spectrograph. In this phase of the process, an algorithm will evaluate the performance of each instrument and then calculate the final corrections needed to achieve a well-aligned telescope across all science instruments. Following this, Webb's final alignment step will begin, and the team will adjust any small, residual positioning errors in the mirror segments.

By late or early , the team is on track to conclude all aspects of Optical Telescope Element alignment and move on to approximately two months of science instrument preparations. Webb's first full-resolution imagery and science data will be released in early to mid-.

Webb is an international program led by NASA with its partners, the European Space Agency and the Canadian Space Agency. Webb's science operations are overseen for NASA by the Space Telescope Science Institute in Baltimore.

Abridged text is reprinted courtesy of NASA

Canada's FGS on Webb successfully used in mirror alignment phase

Credits: CSA, NASA

The Fine Guidance Sensor (FGS) on the James Webb Space Telescope, a mission-critical element designed and built in Canada, was used in tracking mode for the first time as part of the telescope's mirror alignment process.

On , the Webb team performed "Line of Sight" testing that confirmed the FGS's ability to "lock on" to a specific guide star in tracking mode. This mode allows the FGS to transmit highly precise information to Webb's positional system 16 times per second.

The successful FGS operation is the latest in a series of smooth manoeuvres for the massive observatory. After its launch on , the telescope underwent a delicate, month-long unfolding process as it travelled to its final destination, the second Lagrange point (L2).

Most recently, the team released an image mosaic of Webb seeing its first star: it shows 18 views of the same star – one for each of the 18 hexagonal segments that make up Webb's primary mirror.

In the coming weeks, with the help of the FGS, each mirror segment will be carefully adjusted to "stack" these views and calibrate the rest of the telescope's optical elements, to ultimately create a highly focused image of a single star.

The months-long mirror alignment process affords time for Webb's scientific instruments to shed heat. Because Webb will perform its observations in infrared light, its sensitive instruments, like Canada's NIRISS, must be extremely cold. They will gradually cool to an operating temperature of about -233 degrees Celsius.

Once the instruments have reached the correct temperature, Canada's FGS will be used throughout their commissioning, set to begin around the end of .

Photons received: Webb sees its first star – 18 times

Initial alignment mosaic

Credit: NASA

The James Webb Space Telescope is nearing completion of the first phase of the months-long process of aligning the observatory's primary mirror using the Near Infrared Camera (NIRCam) instrument.

The team's challenge was twofold: confirm that NIRCam was ready to collect light from celestial objects, and then identify starlight from the same star in each of the 18 primary mirror segments. The result is an image mosaic of 18 randomly organized dots of starlight, the product of Webb's unaligned mirror segments all reflecting light from the same star back at Webb's secondary mirror and into NIRCam's detectors.

What looks like a simple image of blurry starlight now becomes the foundation to align and focus the telescope in order for Webb to deliver unprecedented views of the universe this summer. Over the next month or so, the team will gradually adjust the mirror segments until the 18 images become a single star.

Segment identification mosaic

This image mosaic was created by pointing the telescope at a bright, isolated star in the constellation Ursa Major known as HD 84406. This star was chosen specifically because it is easily identifiable and not crowded by other stars of similar brightness, which helps reduce background confusion. Each dot within the mosaic is labelled by the corresponding primary mirror segment that captured it. These initial results closely match expectations and simulations. (Credit: NASA)

During the image capturing process that began on , Webb was repointed to 156 different positions around the predicted location of the star and generated 1,560 images using NIRCam's 10 detectors, amounting to 54 gigabytes of raw data. The entire process lasted nearly 25 hours, but notably the observatory was able to locate the target star in each of its mirror segments within the first six hours and 16 exposures. These images were then stitched together to produce a single, large mosaic that captures the signature of each primary mirror segment in one frame. The images shown here are only a centre portion of that larger mosaic, a huge image with over 2 billion pixels.

Each unique dot visible in the image mosaic is the same star as imaged by each of Webb's 18 primary mirror segments, a treasure trove of detail that optics experts and engineers will use to align the entire telescope. This activity determined the post-deployment alignment positions of every mirror segment, which is the critical first step in bringing the entire observatory into a functional alignment for scientific operations.

NIRCam is the observatory's wavefront sensor and a key imager. It was intentionally selected to be used for Webb's initial alignment steps because it has a wide field of view and the unique capability to safely operate at higher temperatures than the other instruments. It is also packed with customized components that were designed to specifically aid in the process. NIRCam will be used throughout nearly the entire alignment of the telescope's mirrors. It is, however, important to note that NIRCam is operating far above its ideal temperature while capturing these initial engineering images, and visual artifacts can be seen in the mosaic. The impact of these artifacts will lessen significantly as Webb draws closer to its ideal cryogenic operating temperatures.

Primary mirror 'selfie'

This "selfie" was created using a specialized pupil imaging lens inside of the NIRCam instrument that was designed to take images of the primary mirror segments instead of images of space. This configuration is not used during scientific operations and is used strictly for engineering and alignment purposes. In this case, the bright segment was pointed at a bright star, while the others aren't currently in the same alignment. This image gave an early indication of the primary mirror alignment to the instrument. (Credit: NASA)

Moving forward, Webb's images will only become clearer, more detail-laden, and more intricate as its other three instruments arrive at their intended cryogenic operating temperatures and begin capturing data. The first scientific images are expected to be delivered to the world in the summer. Though this is a big moment, confirming that Webb is a functional telescope, there is much ahead to be done in the coming months to prepare the observatory for full scientific operations using all four of its instruments.

Abridged text is reprinted courtesy of NASA

Wakey wakey! Webb's instruments are on!

Fully deployed James Webb Space Telescope

Artist conception of the fully deployed James Webb Space Telescope. (Credit: NASA GSFC/CIL/Adriana Manrique Gutierrez)

Now that Webb has reached its home orbit, 1.5 million kilometres away from Earth, the instruments have carefully been awoken. The telescope's four instruments and the Canadian Space Agency's (CSA's) Fine Guidance Sensor (FGS) were turned on one by one. Functionality checks will be performed over the coming days.

The FGS will play a crucial role in the alignment of Webb's 18 golden hexagonal mirrors, as the Optical Telescope Element begins its critical fine-tuning in space.

The commissioning of the instruments, including the CSA's Near-Infrared Imager and Slitless Spectrograph (NIRISS), is expected to start once mission teams have confirmed the successful completion of mirror alignment.

Over the course of the mission, the FGS will act as a stellar navigator, tracking bright stars to keep the telescope aligned, while NIRISS will be used to observe astronomical objects, such as exoplanets, brown dwarfs and rogue planets.

Launched , Webb will use infrared light to study the early universe and observe distant stars, exoplanet atmospheres, galaxy evolution, and much more. Canadian astronomers will be some of the first to use Webb's data and benefit from the tremendous science opportunities offered by this one-of-a-kind observatory.

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