- World
- Jul 13
First images from James Webb Space Telescope reveal unseen Universe
• The dawn of a new era in astronomy has begun as the world gets its first look at the full capabilities of the James Webb Space Telescope (JWST). The telescope’s first full-colour images and spectroscopic data, which uncover a spectacular collection of cosmic features that have remained elusive until now, were released.
• The James Webb Space Telescope is the world’s premier space science observatory.
• Webb’s first observations tell the story of the hidden universe through every phase of cosmic history – from neighboring planets outside our solar system, known as exoplanets, to the most distant observable galaxies in the early universe.
• The latest images showed parts of the universe seen by other telescopes. But Webb’s sheer power, distant location off Earth and use of the infrared light spectrum showed them in new light.
• Webb’s use of the infrared light spectrum allows the telescope to see through the cosmic dust and see light from faraway light from the corners of the universe.
James Webb Space Telescope
• It reached its lookout point 1.6 million kilometers from Earth in January.
• Then the lengthy process began to align the mirrors, get the infrared detectors cold enough to operate and calibrate the science instruments, all protected by a sunshade the size of a tennis court that keeps the telescope cool.
• It is designed to answer fundamental questions about the universe and to make breakthrough discoveries in all fields of astronomy.
• A joint effort with ESA (European Space Agency) and the Canadian Space Agency, the Webb observatory is NASA’s revolutionary flagship mission to seek the light from the first galaxies in the early universe and to explore our own solar system, as well as planets orbiting other stars.
• JWST is the scientific successor to the iconic Hubble and Spitzer space telescopes. It is built to complement and further the discoveries of Hubble, Spitzer, and other NASA missions by accessing the near infrared and mid-infrared wavelengths with unprecedented resolution.
• It is named after NASA’s second administrator, James E. Webb, who headed the agency during part of the Apollo era, from February 1961 to October 1968. The mission was previously known as the Next Generation Space Telescope (NGST).
• JWST is about 100 times more sensitive than Hubble and is expected to transform understanding of the universe and our place in it.
• JWST carries four state-of-the-art science instruments with highly sensitive infrared detectors of unprecedented resolution. It studies infrared light from celestial objects with much greater clarity than ever before.
What are the components of JWST?
• JWST is engineered to build upon the groundbreaking discoveries of other spacecraft, such as the Hubble Space Telescope and the Spitzer Space Telescope. While Hubble views the universe in visible and ultraviolet light, JWST focuses on infrared, a wavelength important for peering through gas and dust to see distant objects.
• One of JWST’s main components is the sunshield, a diamond-shaped structure roughly the area of a tennis court. The sunshield will keep the telescope in perpetual shadow for operations at –233°C, to prevent the telescope’s own infrared emission from overwhelming the signals from the astronomical targets.
• The telescope’s primary mirror is made of 18 hexagonal-shaped mirror segments, each 1.32 metres in diameter and weighing approximately 20 kilograms. The total diameter of JWST’s primary mirror spans 6.5 metres, which is so large that it was carefully folded into the rocket’s fairing for launch. Each of the telescope’s mirrors is covered in a microscopically thin layer of gold, which optimises them for reflecting infrared light – the main wavelength of light this telescope will observe. It is the largest mirror ever flown into space.
The first images of the JWST
1) SMACS 0723
The JWST has delivered the deepest, sharpest infrared image of the distant Universe so far. Known as Webb’s First Deep Field, this is galaxy cluster SMACS 0723 and it is teeming with thousands of galaxies – including the smallest, faintest objects ever observed.
This image shows the galaxy cluster SMACS 0723 as it appeared 4.6 billion years ago, with many more galaxies in front of and behind the cluster. Light from these galaxies took billions of years to reach us. We are looking back in time to within a billion years after the big bang when viewing the youngest galaxies in this field. The light was stretched by the expansion of the Universe to infrared wavelengths that Webb was designed to observe. Researchers will soon begin to learn more about the galaxies’ masses, ages, histories, and compositions.
SMACS 0723 can be viewed near the constellation Volans in the southern sky.
2) WASP-96b (spectrum)
Webb’s detailed observation of this hot gas giant exoplanet WASP-96b outside our solar system reveals the clear signature of water, along with evidence of haze and clouds that previous studies of this planet did not detect. With Webb’s first detection of water in the atmosphere of an exoplanet, it will now set out to study hundreds of other systems to understand what other planetary atmospheres are made of.
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, 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 3.5 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.
3) Southern Ring Nebula
Planetary nebulae are the shells of gas and dust ejected from dying stars. The JWST has revealed details of the Southern Ring planetary nebula that were previously hidden from astronomers. It is approximately 2,500 light-years away.
Webb’s powerful infrared view brings this nebula’s second star into full view, along with exceptional structures created as the stars shape the gas and dust around them. New details like these, from the late stages of a star’s life, will help us better understand how stars evolve and transform their environments.
From birth to death as a planetary nebula, Webb can explore the expelling shells of dust and gas of aging stars that may one day become a new star or planet.
4) Carina Nebula
Webb’s look at the ‘Cosmic Cliffs’ in the Carina Nebula unveils the earliest, rapid phases of star formation that were previously hidden.
What looks much like craggy mountains on a moonlit evening is actually the edge of a nearby, young, star-forming region known as NGC 3324. Called the Cosmic Cliffs, this rim of a gigantic, gaseous cavity is roughly 7,600 light-years away.
The cavernous area has been carved from the nebula by the intense ultraviolet radiation and stellar winds from extremely massive, hot, young stars located in the centre of the bubble, above the area shown in this image. The high-energy radiation from these stars is sculpting the nebula’s wall by slowly eroding it away.
NGC 3324 was first catalogued by James Dunlop in 1826. Visible from the Southern Hemisphere, it is located at the northwest corner of the Carina Nebula (NGC 3372), which resides in the constellation Carina. The Carina Nebula is home to the Keyhole Nebula and the active, unstable supergiant star called Eta Carinae.
5) Stephan’s Quintet
Webb’s view of this compact group of galaxies, located in the constellation Pegasus, pierced through the shroud of dust surrounding the center of one galaxy, to reveal the velocity and composition of the gas near its supermassive black hole. Now, scientists can get a rare look, in unprecedented detail, at how interacting galaxies are triggering star formation in each other and how the gas in these galaxies is being disturbed.
Together, the five galaxies of Stephan’s Quintet are also known as the Hickson Compact Group 92 (HCG 92). Although called a “quintet”, only four of the galaxies are truly close together and caught up in a cosmic dance. The fifth and leftmost galaxy, called NGC 7320, is well in the foreground compared with the other four. NGC 7320 resides 40 million light-years from Earth, while the other four galaxies (NGC 7317, NGC 7318A, NGC 7318B, and NGC 7319) are about 290 million light-years away. This is still fairly close in cosmic terms, compared with more distant galaxies billions of light-years away. Studying these relatively nearby galaxies helps scientists better understand structures seen in a much more distant universe.
This proximity provides astronomers a ringside seat for witnessing the merging of and interactions between galaxies that are so crucial to all of galaxy evolution. Rarely do scientists see in so much exquisite 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.
Stephan’s Quintet was discovered by the French astronomer Edouard Stephan in 1877.
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