The James Webb Space Telescope (JWST) is the premier telescope of the next decade. The James Webb will study every phase in the Universe’s history from the first glows after the Big Bang to the formation of solar systems. JWST is a large infrared telescope with a primary mirror of approximately 6.5-meter diameter.
This massive telescope was an international collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA). James Webb was successfully launched on December 25th, 2021 and has already revealed many wonders of the Universe.
Image Credit: NASA
The extremes of space force researchers and scientists to constantly push past the boundaries of our current technology. This was no different with James Webb, many innovations were developed to make this telescope possible. The largest part of JWST is its five-layer sunshield the size of a tennis court.
This sunshield reduces heat from the Sun by more than a million times. James Webb’s primary mirror is made up of 18 separate segments, giving it a honeycomb look. These segments are folded in for protection during launch then unfolded and adjusted to shape after James Webb was in position. These mirrors are made of ultra-lightweight beryllium. These and many more innovations work together to give us this next generation telescope.
There are four instruments on James Webb, the Near Infrared Camera (NIRCam), the Near Infrared Spectrograph (NIRSpec), the Mid Infrared Instrument (MIRI), and the Fine Guidance Sensors/Near Infrared Imager and Slitless Spectrograph (FGS/NIRISS).
The Near Infrared Camera is James Webb’s primary imager. It covers the near infrared range of the electromagnetic spectrum from 0.6 to 5 microns. NIRCam is equipped with coronagraphs, instruments that allow for the imaging of faint objects near a bright object.
NIRCam’s coronagraphs work by blocking out the brighter objects light, allowing for the dimmer object to be seen. These coronagraphs will help astronomers determine characteristics of exoplanets orbiting stars. NIRCam will detect light from the earliest stars and galaxies, stars in nearby galaxies, young stars in the Milky Way, and objects in the Kiper Belt (the ring of objects surrounding our solar system out past Pluto).
The Near Infrared Spectrometer will operate in the same wavelength range (0.6-5 microns) as the NIRCam. Spectrographs observe light from an object and disperse it into a spectrum. Similar to how a white light shown through a prism reveals a rainbow on the other side. Scientist can analyze the spectrum to determine many physical properties of the object, such as temperature, chemical composition, and even mass. A spectrum can be thought of like the object’s fingerprint.
The Mid-Infrared Instrument is comprised of both a camera and spectrograph. Being a mid-infrared device this instrument focuses on the wavelength range of 5 to 28 microns. These wavelengths are not visible to the human eye. MIRI will allow us to see newly forming stars, distant galaxies, objects in the Keiper Belt, and very faint comets.
The Fine Guidance Sensor (FGS) is what allows James Webb to point precisely at an object and obtain high quality images. The Near Infrared Imager and Slitless Spectrograph (NIRISS) will investigate the first light after the Big Bang, spectroscopy of exoplanets as they transit in front of their stars, and the detection and characterization of exoplanets. NIRISS operates over the wavelength range of 0.8 to 5 microns.
Image Credit: NASA
James Webb’s Amazing Images, So Far
This is the largest image so far by James Webb. It covers a space that is the size of one fifth of the Moon’s diameter. It was captured by both NIRCam and MIRI. Stephan’s Quintet is a grouping of five galaxies. With the powerful resolution of JWST we are able to see details we have never seen before. We can now see clusters of young stars and starburst regions of new star birth.
The gravitational interactions between these galaxies pull dust and gas from each other, which we can now see as tails trailing from some of the galaxies. The most dramatic thing we can see in this image is shock waves being emitted as one of the galaxies smashes through the cluster. These shock waves are the red and gold streaks between galaxies.
Stephan’s Quintet is important to astronomers studying galaxy evolution. A key part of galaxy evolution is the interactions and merging of galaxies. JWST has provided details of interacting galaxies rarely seen before, allowing astronomers to use Stephan’s Quintet as a “laboratory” to study these processes. These new insights will provide valuable insights into how galaxy evolution may have been driven by galactic interactions in the early Universe.
The Tarantula Nebula is a star forming region spanning 340 light-years across. The James Webb’s NIRCam captured this image and revealed thousands of young stars never seen before. These stars are covered in dust and were previously undetectable until NIRCam. The pale blue region is the most actively forming stars.
Exploring this image, we see an older star to the upper left of the pale blue star forming region. This star appears to have spikes, an artifact of the telescope. If you follow the top spike upward, you can see a small bubble. This bubble is caused by young stars blowing out dusty material.
The rusty color of the outer regions of the nebula tells astronomers that there are large amounts of hydrocarbons in the Tarantula Nebula. James Webb is allowing us to study this stellar nursery in greater detail than ever before.
Southern Ring Nebula
JWST’s NIRCam image of the Southern Ring Nebula has revealed many layers of detail. At the center of this nebula is a bright star, but this star is not the nebula’s source. The nebula’s source is a star that is now barely visible at the bottom left of the bright star’s diffraction spikes.
This origin star ejected at least eight layers of gas and dust over thousands of years. The central bright star has changed the shape of the nebula’s rings by creating turbulence. The jaggedness of the rings is caused by the two stars orbiting each other. As the origin star orbits it emits gas and dust in a variety of directions.
If you look closely, you can see hundreds of brightly lit lines shooting through the rings of the nebula. These come from the bright star and stream through holes in the nebula, like sunlight streaming through clouds.
This image is a composite image from both NIRCam and MIRI. It depicts the Cartwheel galaxy and its companion galaxies. By creating a composite image, we can see details that would be hard to see in the individual images. MIRI data is colored red and NIRCam data is given colors blue, orange, and yellow.
Approximately 400 million years ago there was a high-speed collision that resulted in the formation of the Cartwheel galaxy. There are two rings, a bright inner ring, and a colorful outer ring. These rings expand outward from the collision like shockwaves. Even though this was a massive collision there are many features of the original spiral galaxy remaining.
The old spiral galaxy’s rotating arms are seen in the “spokes” of the cartwheel. This image will allow astronomers to study both galaxy evolution and star formation in great detail.
“Cosmic Cliffs” in the Carina Nebula
These “Cosmic Cliffs” are a star-forming region at the edge of the Carina Nebula. James Webb’s NIRCam reveals areas of star birth that were previously obscured. These cliffs are at the edge of a giant gas cavity in the NGC 3324 star-forming region of the Carina Nebula. This giant cavity was carved out in the nebula from the radiation and solar winds of newly formed stars in the center of the bubble, shown in the top half of the image.
There are key features seen in the image. There appears to be steam rising from the “mountains”. This is hot ionized gas. Pillars rise up against the glowing wall of gas resisting the radiation from the young stars. Radiation from newly formed stars blow bubbles in cavities in the surrounding dust.
It is hard to capture this period of star formation in a star’s life. For one star it only lasts 50,000 – 100,000 years. James Webb’s sensitivity and resolution have allowed us to capture this spectacular event.
Pillars of Creation
Both MIRI and NIRCam captured the Pillars of Creation. With NIRCam we see a range of bright colors. Newly forming stars can be seen in the knots in the pillars as red orbs. Around the edges of the pillars there are wavy lines that resemble lava. These are ejections from stars that are still forming.
MIRI’s images however gives these pillars a more sinister view. We no longer view the thousands of stars and instead see thick layers of gas and dust. Dust is a key ingredient for star formation and is very important for us to study. Both of the MIRI and NIRCam images allow astronomers to study star formation like never before.
The James Webb Space Telescope is the defining telescope of this generation. Like Hubble, James Webb will provide us with not only beautiful images but also reveal hidden secrets of our Universe.