What scientific discoveries reveal the wonderful images of the James Webb Telescope?

Less than six months after the James Webb Telescope was launched into space, it has already begun to reveal the secrets of the universe. Right behind these images from a sci-fi movie, there’s a true science-fiction leap in play. Things never seen before have revealed themselves to researchers.

Read also: James Webb Telescope: Why would it revolutionize our knowledge of space?

“These images are an important shortcut to communicating with the general public. We will choose datasets that are beautiful to the eye, it allows us to share our joy of owning this tool with everyone.” Beyond the beauty of the images, Nicole Nesvadba, Research Director of the National Center for Scientific Research (CNRS) at the Observatory of the Côte d’Azur, explains how these wonderful images open wide the doors to a new world for scientists.

The first image of James Webb, the deepest image of the universe

This deep field is the first image from the James Webb Space Telescope, posted by US President Joe Biden on Twitter. | NASA/AFP

This is the first image of the James Webb Telescope, which Joe Biden revealed to the public on July 11, 2022. In this shot, the deepest image of the universe ever taken, NASA remembers, we see stars and galaxies. The image is a little distorted because to get it the scientists used a file gravity lens : “Large masses – here the cluster of galaxies – change the shape of space, and the light follows this distortion. Thanks to this effect, you get the equivalent of a magnifying glass.”

This technique revealed the light of galaxies and star clusters very far away, and for some, never seen before.

A blessing to scholars. “What interests us most are the very small red dots which are not very spectacular”, Refers to Nicole Nesvadba. These objects are very distant galaxies, which have not been observed before. They are very far away, and by the influence of physics, their color, initially blue, comes to us in red. their age? They will date back 400 million years after the creation of the universe, 13.7 billion years ago.

Scientists will study these galaxies, which are the oldest for us, and the youngest from the point of view of the creation of the universe, which were formed immediately after the Big Bang. They will be interested in their properties, mass, number, etc. They hope to learn more about the formation of the universe.

The Southern Ring Nebula, or How Stars Die

In this image, the star (the center) has been spewing gas and dust for thousands of years in all directions, forming a planetary nebula. | NASA/AFP

Here is a dying star. In the image on the right, in the center of this shot of the Southern Ring Nebula, we can see two very close stars. “One of them is dying and ejects layers of matter in the form of gas and dust, forming a nebula.”. These gases are shown in blue in the image on the left. Dust appears red over the nebula’s surroundings.

“Some stars, when they use up all the fuel to run the thermonuclear process, expel their outer parts, which will form these very beautiful structures.”Nicole Nsvadba explains. This process, which will one day happen to our sun, continues for tens of thousands of years.

The different rings represent successive layers ejected by the star. Thanks to this image, scientists will be able to go back in time and make a history of this system.

The other star in the center of the image is less developed. It was not yet time for her to die. When we say ‘less developed,’ we are not necessarily talking about age, but above all about mass. » It’s quite counter-intuitive, but it’s the low-mass stars that live the longest: they don’t burn their fuel as fast as massive stars, which must die faster. It is somewhat similar to an SUV that consumes its fuel faster than the Twingo.

This slow pain also represents a step toward the formation of another generation of stars: Dust emitted during this process, after space travel, sometimes for billions of years, can be incorporated into a new star. training.

Cartwheel Galaxy: When two galaxies collide at high speed

Stunning image of the Cartwell Wheel Galaxy, which owes its shape to the collision between two galaxies. | NASA / European Space Agency

Besides its amazing aspect, the Cartwheel Galaxy is a symbolic object, “Intuitive” by scientists, says Nicole Nesvadba.

Its special shape is due to a high-speed collision between a small galaxy (not visible in the image) and a large galaxy (on the right), 400 million years ago. The galaxy consists of two rings: a bright inner ring and a colorful outer ring. Both expand, gradually moving away from the point of impact, like shock waves.

In the image, red tints represent dust. Every little blue dot is a nursery of stars. “The collision led to a phase of star formation, with the formation of new stars in the galaxy,” Nicole Nsvadba explains.

Here is the difference between the observations of the Hubble Telescope and James Webb:

Why does science care about this thing? Because although this type of event is rare, the physical processes behind it are global. » The goal of astrophysicists: to study the birth of stars. “We don’t know yet how stars are formed, it’s a bit embarrassing. We only understand the main lines. This is one of the most researched areas today.”

‘Cosmic Cliffs’ in the Carina Nebula: A Nursery of Stars

This is an image of a star forming core, taken in the Carina Nebula, 7,600 light-years from Earth. The brown ‘little ‘fingers are the sites where new solar systems are born’Surrounded by thick dust and gas the researcher notes.

It’s a region never seen before, covered in dust, that blinded James Webb’s predecessor, the Hubble telescope.

This rugged area and “cavernous”some of them “tops” Measuring about seven light-years across, it’s formed by the intense ultraviolet radiation and stellar winds of young, massive stars, like the ones we can guess out of sight, at the top right of the image.

Her warm light ruined and repelled the dust that surrounded her at birth. This is why we observe two distinct regions: once stars form in these dust clouds, they will disperse the gas and destroy the dust, thus becoming like the blue region. For a bright star, this has already happened. This process takes a million years. “What is interesting is the interface between the blue part and the brown part: these are very complex effects of star formation.” This vaporous region is made up of hot gas and dust from the nebula and its radiation.

Scientists hope to understand why some stars are larger than others, and the role of each in these nebulae.

Stefan’s Quintet: When Galaxies Collide

Stephan’s Quintet, via the James Webb Telescope. | NASA/AFP

It’s the largest image ever captured by a telescope: it contains 150 million pixels and is made up of nearly 1,000 separate images. It shows five galaxies, a group called Stefan Quintet, named after its discoverer, Marseille astronomer Edouard Stefan, in 1878.

In fact, only four of these galaxies exist Relativesthe fifth is much further. “What is amazing about this picture is the transparency of yellow light and starlight”, notes Nicole Nsvadba. This achievement was made possible by the unique capabilities of the James Webb Telescope.

The proximity between these galaxies allows scientists to study their interactions more precisely, which is crucial in their evolution, NASA points out: in this, Stephan’s Quintet is like a laboratory to discover how they cause stars to form among themselves, how gases interact, etc. .

According to the US space agency, such clusters of galaxies were more common in the early ages of the universe. Their material may have fueled highly energetic black holes called quasars. One of these galaxies is also home to a supermassive black hole, with a mass 24 million times the mass of the Sun. A black hole examined by James Webb, with a level of detail never seen before.

The goal for scientists: to understand at what rate supermassive black holes feed and grow.

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