IN 2022, THE JAMES WEBB SPACE TELESCOPE PROVIDED US WITH NEW VIEWS OF THE UNIVERSE
This year marked the end of a decades-long wait for astronomers. The James Webb Space Telescope is finally in action.
The telescope, which is scheduled to launch in December 2021, released its first science data in July (SN: 8/13/22, p. 30) and quickly exceeded astronomers' expectations.
"We discovered that James Webb is ten times more sensitive than we predicted" for certain types of observations, says Sasha Hinkley of the University of Exeter in England. In September, his team published the telescope's first direct image of an exoplanet (SN: 9/24/22, p. 6). "The people who worked so hard to get this right, to launch something the size of a tennis court into space on a rocket and get this sensitive machinery to work perfectly," he says. And I consider myself extremely fortunate to be the recipient of this."
The JWST telescope, also known as the Hubble Space Telescope, was designed to peer further back into the history of the universe than ever before (SN: 10/9/21 & 10/23/21, p. 26). It is more powerful and sensitive than its predecessor, the Hubble Space Telescope. JWST can also see distant and veiled objects that were previously hidden because it looks in much longer wavelengths of light.
JWST spent its first few months collecting "early-release" science data, or observations that put the telescope's various vision modes to the test. "It is a very, very new instrument," astronomer Lamiya Mowla of the University of Toronto says. "It will take some time before we can characterize all of the different observation modes of all four on-board instruments."
The need for testing, combined with the excitement, has caused some consternation among astronomers in these heady early days. Because data from the telescope was in such high demand, the operators had not yet calibrated all of the detectors before releasing it. The JWST team is providing calibration data to researchers so that they can properly analyze the data. "We knew there would be calibration issues," Mowla says.
The raw numbers extracted by scientists from some of the initial images may need to be slightly revised. However, the images are real and reliable, despite the fact that translating the telescope's infrared data into colorful visible light requires some artistry (SN: 3/17/18, p. 4).
The stunning images that follow are just a few of the shiny new observatory's early highlights.
The Vastness Of Space
JWST has captured the most detailed images of the universe to date (above). SMACS 0723 (bluer galaxies) galaxy cluster is 4.6 billion light-years away from Earth. It acts as a massive cosmic lens, allowing JWST to focus on thousands of even more distant galaxies that were visible 13 billion years ago (the redder, more stretched galaxies). The far-off galaxies appear different in the mid-infrared light captured by the telescope's MIRI instrument (above left) than in the near-infrared light captured by NIRCam (above right). The first follows dust, while the second follows starlight. Stars abound in early galaxies, but there is little dust.
Rings Encircling Neptune
JWST was designed to peer across vast cosmic distances, but it also provides new insights into our solar system's neighbors. This image of Neptune was the first close-up of its delicate-looking rings in more than 30 years (SN: 11/5/22, p. 5).
Under Duress
The rings in this incredible photograph are not an optical illusion. They are made of dust, and a new ring is added every eight years when the two stars in the image's center approach each other. One of the stars is a Wolf-Rayet star nearing the end of its life and puffing out dust. The cyclical dusty eruptions allowed scientists to directly measure how starlight pressure pushes dust around for the first time (SN: 11/19/22, p. 6).
Hit-and-run By The Galaxy
Astronomers intend to use JWST's unprecedented sensitivity to compare the earliest galaxies to more modern galaxies in order to understand how galaxies grow and evolve. This galactic collision, the main remnant of which is known as the Cartwheel galaxy, represents a step in that epic process (SN Online: 8/3/22). A smaller galaxy that fled the scene has pierced the large central galaxy (right in the above composite) (not in view). A visible light image of the scene was previously captured by the Hubble Space Telescope (top half). However, JWST's infrared eyes have revealed far more structure and complexity in the galaxy's interior (bottom half).
Portrait Of An Exoplanet
HIP 65426b, a gas giant, was the first exoplanet to be photographed by JWST (each inset shows the planet in a different wavelength of light; the star symbol indicates the location of the planet's parent star). When compared to some of the other spectacular JWST images, this one from astronomer Sasha Hinkley and colleagues doesn't look like much. However, it will provide information about the planet's atmosphere and demonstrate the telescope's ability to perform similar research on even smaller, rocky exoplanets (SN: 9/24/22, p. 6).
Shake Off The Dust
The Pillars of Creation is another classic Hubble image that has been updated by JWST. This star-forming region was shrouded in dust when Hubble observed it in visible light (above left). JWST's infrared vision reveals gleaming new stars (above right).
Source : ScienceNews