NASA has revealed the first set of images from the new James Webb Space Telescope, revealing the universe’s beauty at an unprecedented scale. The images showed the birthplaces of stars and the “cosmic dance” orchestrated by galaxies with supermassive black holes within them to the last gasps of a dying star. Here are 5 important things you need to know about the new images from Webb Telescope images.
The most exciting picture for scientists is not a picture at all
Image credit: NASA, ESA, CSA, and STScI
The second ‘image’ that NASA revealed was the spectrographic data of the planet WASP-96b, which is more than 1,150 light-years away. While this could have been the most underwhelming reveal for the layman, it actually presents one of the most interesting new possibilities with Webb. The ability to look for the presence of particular molecules like those of hydrogen or oxygen in distant planets and cosmic bodies.
This spectrum revealed by NASA is one of the most detailed near-infrared transmission spectrums of an exoplanet that has ever been captured. It also covers a wide range of wavelengths, including visible red light and a portion of the spectrum that has not previously been accessible from other telescopes, in particular, wavelengths longer than 1.6 microns.
This part of the spectrum is particularly sensitive to water and other key molecules like oxygen, methane and carbon dioxide. This is not immediately obvious in the WASP-96b spectrum. But it could potentially be detected in other exoplanets that Webb observes in the future.
New light on star formation
This landscape of “mountains” and “valleys” speckled with glittering stars is actually the edge of a nearby, young, star-forming region called NGC 3324 in the Carina Nebula. Image credit: NASA, ESA, CSA, and STScI
The observations used to create this image of NGC 3324 in the Carina Nebula will help scientists learn more about the process of star formation. What looks like mountains are actually the interplay between the clouds of dust and gaseous cavities. The expansion of these eroding cavities triggers star births.
The bright ionised rim of the cavity slowly pushes into the gas and dust. If the rim encounters an unstable material, there will be increased pressure, causing the material to collapse and form new stars. But almost counter-intuitively, this type of disturbance can also prevent the formation of a star as the star-making material could get eroded. So, there is a fine line between sparking star formation and stopping it.
Webb will help address some of the most important questions of modern astrophysics like what determines the number of stars in a particular region and why stars form with a certain mass.
How galaxies and black holes work evolve
Stephan’s Quintet as captured by the Webb space telescope. Image credit: NASA, ESA, CSA, and STScI
The proximity between four of the five galaxies in Stephan’s quintet means that scientists are given a good view into the merging of and interaction between galaxies which is crucial to their evolution. Scientists rarely get to witness how interacting galaxies trigger star formation in each other and how the gas in these galaxies is disturbed by the interaction. The compact group could be thought of as a great laboratory for studying such processes.
Such groups of galaxies packed relatively close to each other might have been much more common during the early age of the galaxies when the gravitational forces of highly energetic black holes called quasars held them together. Even as we see the quintet now, the topmost galaxy in the group has a supermassive black hole at its centre. The active galactic nucleus is 24 million times the mass of the Sun.
How a dying star affects its neighbours
The landscape of the Southern Ring Nebula is dominated by two stars locked in a tight orbit. Image credit: NASA, ESA, CSA, and STScI
The landscape of the Southern Ring Nebula is dominated by two stars locked in a tight orbit. Webb’s infrared images feature new details in this complex system. The dimmer star has been sending out clouds of gas and dust for thousands of years. The brighter star is in an earlier stage of its life and will probably eject its own planetary nebula in the future. But in the meanwhile, the pair of stars orbit each other and “stir the pot” of gas and dust creating patterns.
Each “shell” of gas represents a time when the fainter star lost some of its mass. The wider shells of gas in the outer areas of the image were ejected earlier while those closest to the stars were ejected more recently. Scientists can trace these ejections to look into the history of the system.
Looking back in time
The galaxy cluster SMACS 0723 as it was captured by Webb space telescope. Image credit: NASA, ESA, CSA, and STScI
The first image revealed by NASA shows the galaxy cluster SMACS 0723, which is almost 4.6 billion years away. This galaxy cluster causes a phenomenon known as “gravitational lensing”, where the gravitational force of the galaxies in the foreground distorts the light behind it to create a sort of magnifying glass, allowing us to see much fainter and distant objects behind it.
The light from these galaxies took billions of years to reach Webb. For some of the youngest galaxies that can be viewed in this wide-field image, we are seeing them as they were about 13.1 billion years ago, within the first billion years after the original big bang.
