James Web Space Telescope’s historic first image
NASA today, via President Joe Biden and Vice President Kamala Harris, released the first historic images from NASA’s James Web Space Telescope, the most powerful telescope ever launched into space. The image showed the most high-resolution image of the universe ever seen by human eyes. Known as Webb’s First Deep Field, this image of galaxy cluster SMACS 0723 is overflowing with detail. Thousands of galaxies – including the faintest objects ever observed in the infrared – have appeared in Webb’s view for the first time. This slice of the vast universe covers a patch of sky approximately the size of a grain of sand held at arm’s length by someone on the ground.
President Biden said,
“Today is a historic day. It’s a new window into the history of our universe and today we’re going to get a first glimpse of the light to shine through that window… These images remind the world that America can achieve big things!”
Why the James Webb Space Telescope is such a big deal
Webb has been going through a six-month period of preparation before it can begin science work, calibrating its instruments to its space environment and aligning its mirrors. Building on the technology of the Hubble Space Telescope, JWST’s stunning resolution will enable viewing of objects too old, distant, or faint for the Hubble Space Telescope, essentially allowing us to see the universe turn the lights on for the first time. It could fundamentally transform our understanding of the Universe, revealing space anomalies we have yet to even think of. Jonathan Gardner, Webb deputy senior project scientist at NASA, explained:
“Webb can see backwards in time just after the big bang by looking for galaxies that are so far away, the light has taken many billions of years to get from those galaxies to us. Webb is bigger than Hubble so that it can see fainter galaxies that are further away.”
These will be the first of many images to come from Webb, the most powerful telescope ever launched into space. In fact, the mission, originally expected to last for 10 years, has enough excess fuel capability to operate for 20 years. During this period, we can expect a plethora of discoveries using more than a dozen different methods.
The James Webb Space Telescope’s 17 modes of operation
During this mission, NASA will operate JWST through 17 modes. Those modes include:
1. Near-Infrared Camera (NIRCam) imaging. Near-infrared imaging will take pictures in part of the visible to near-infrared light, 0.6 to 5.0 micrometers wavelength.
2. NIRCam wide field slitless spectroscopy. Spectroscopy separates the detected light into individual colors. Slitless spectroscopy spreads out the light in the whole instrument field of view so we see the colors of every object visible in the field.
3. NIRCam coronagraphy. When a star has exoplanets or dust disks in orbit around it, the brightness from a star usually will outshine the light that is reflected or emitted by the much fainter objects around it. Coronagraphy uses a black disk in the instrument to block out the starlight in order to detect the light from its planets.
4. NIRCam time series observations – imaging. Most astronomical objects change on timescales that are large compared to human lifetimes, but some things change fast enough for us to see them. Time series observations read out the instruments’ detectors rapidly to watch for those changes.
5. NIRCam time series observations – grism. When an exoplanet crosses the disk of its host star, light from the star can pass through the atmosphere of the planet, allowing scientists to determine the constituents of the atmosphere with this spectroscopic technique. Scientists can also study light that is reflected or emitted from an exoplanet, when an exoplanet passes behind its host star.
6. Near-Infrared Spectrograph (NIRSpec) multi-object spectroscopy. Although slitless spectroscopy gets spectra of all the objects in the field of view, it also allows the spectra of multiple objects to overlap each other, and the background light reduces the sensitivity. NIRSpec has a microshutter device with a quarter of a million tiny controllable shutters. Opening a shutter where there is an interesting object and closing the shutters where there is not allows scientists to get clean spectra of up to 100 sources at once.
7. NIRSpec fixed slit spectroscopy. In addition to the microshutter array, NIRSpec also has a few fixed slits that provide the ultimate sensitivity for spectroscopy on individual targets.
8. NIRSpec integral field unit spectroscopy. Integral field unit spectroscopy produces a spectrum over every pixel in a small area, instead of a single point, for a total of 900 spatial/spectral elements. This mode gives the most complete data on an individual target.
9. NIRSpec bright object time series. NIRSpec can obtain a time series spectroscopic observation of transiting exoplanets and other objects that change rapidly with time.
10. Near-Infrared Imager and Slitless Spectrograph (NIRISS) single object slitless spectroscopy. To observe planets around some of the brightest nearby stars, NIRISS takes the star out of focus and spreads the light over lots of pixels to avoid saturating the detectors.
11. NIRISS wide field slitless spectroscopy. NIRISS includes a slitless spectroscopy mode optimized for finding and studying distant galaxies. This mode will be especially valuable for discovery, finding things that we didn’t already know were there.
12. NIRISS aperture masking interferometry. NIRISS has a mask to block out the light from 11 of the 18 primary mirror segments in a process called aperture masking interferometry. This provides high-contrast imaging, where faint sources next to bright sources can be seen and resolved for images.
13. NIRISS imaging. Because of the importance of near-infrared imaging, NIRISS has an imaging capability that functions as a backup to NIRCam imaging. Scientifically, this is used mainly while other instruments are simultaneously conducting another investigation, so that the observations image a larger total area.
14. Mid-Infrared Instrument (MIRI) imaging. Just as near-infrared imaging with NIRCam will be used on almost all types of Webb targets, MIRI imaging will extend Webb’s pictures from 5 to 27 microns, the mid-infrared wavelengths. Mid-infrared imaging will show us, for example, the distributions of dust and cold gas in star-forming regions in our own Milky Way galaxy and in other galaxies.
15. MIRI low-resolution spectroscopy. At wavelengths between 5 and 12 microns, MIRI’s low-resolution spectroscopy can study fainter sources than its medium-resolution spectroscopy. Low resolution is often used for studying the surface of objects, for example, to determine the composition.
16. MIRI medium-resolution spectroscopy. MIRI can do integral field spectroscopy over its full mid-infrared wavelength range, 5 to 28.5 microns. This is where emission from molecules and dust display very strong spectral signatures.
17. MIRI coronagraphic imaging. MIRI has two types of coronagraphy: a spot that blocks light and three four-quadrant phase mask coronagraphs. These will be used to directly detect exoplanets and study dust disks around their host stars.
First set of James Web Space Telescope images (and data) released to the public
More high-resolution color images made their debut Tuesday, July 12, one of which, according to NASA Administrator Bill Nelson, “is the deepest image of our universe that has ever been taken.”
The second star in the Southern Ring Nebula comes into full view, along with exceptional structures
NASA’s James Webb Space Telescope has cast the Southern Ring Nebula in an entirely new light. By observing the nebula in mid-infrared wavelengths, Webb has unveiled the second, dusty star at the center of the nebula in far more detail. The star closely orbits its companion as it periodically ejects layers of gas and dust. Together, the swirling duo have created a fantastic landscape of asymmetrical shells. Webb’s near-infrared light image hones in on “spotlights” from the stars, where light travels through holes in the nebula’s dusty ejections.
Stellar nursery in Carina showcases Webb’s cameras
The seemingly three-dimensional “Cosmic Cliffs” showcases Webb’s capabilities to peer through obscuring dust and shed new light on how stars form. Webb reveals emerging stellar nurseries and individual stars that are completely hidden in visible-light pictures. This landscape of “mountains” and “valleys” is actually the edge of a nearby stellar nursery called NGC 3324 at the northwest corner of the Carina Nebula.
So-called mountains — some towering about 7 light-years high — are speckled with glittering, young stars imaged in infrared light. A cavernous area has been carved from the nebula by the intense ultraviolet radiation and stellar winds from extremely massive, hot, young stars located above the area shown in this image. The blistering, ultraviolet radiation from these stars is sculpting the nebula’s wall by slowly eroding it away. Dramatic pillars rise above the glowing wall of gas, resisting this radiation. The “steam” that appears to rise from the celestial “mountains” is actually hot, ionized gas and hot dust streaming away from the nebula due to the relentless radiation.
Objects in the earliest, rapid phases of star formation are difficult to capture, but Webb’s extreme sensitivity, spatial resolution and imaging capability can chronicle these elusive events.
The close proximity of Stephan’s Quintet gives astronomers a ringside seat to galactic mergers and interactions
In an enormous new image, NASA’s James Webb Space Telescope reveals never-before-seen details of the galaxy group called “Stephan’s Quintet.” The close proximity of this group gives astronomers a ringside seat to galactic mergers and interactions. Rarely do scientists see in so much detail how interacting galaxies trigger star formation in each other, and how the gas in these galaxies is being disturbed. Stephan’s Quintet is a fantastic “laboratory” for studying these processes fundamental to all galaxies. The image also shows outflows driven by a supermassive black hole in one of the group’s galaxies in a level of detail never seen before. Tight galaxy groups like this may have been more common in the early universe when superheated, infalling material may have fueled very energetic black holes.
