“This is amazing”: deciphering the very first images of the Euclid telescope

Just over four months after its launch, the European Space Agency’s (ESA) Euclid Space Telescope demonstrated its incredible technical capabilities for the first time this Tuesday. Five images processed over three months by Jean-Charles Couillandre, an astronomer at the Commission for Alternative and Atomic Energy (CEA). He himself cannot believe it: “This resolution is amazing. We see the Universe as we have never seen it before. »

“We now know that Euclid will achieve the goal we have set for ourselves. There is no defect. For those who built the machine, this is a complete success,” rejoices David Elbaz, scientific director of the astrophysics department at CEA Saclay. We are heading to five distant destinations.

Perseus Galaxy Cluster

“This is a real tapestry of galaxies. There are about 100,000 of them. All these small dots, these small blocks are the history of the Universe, unfolding before our eyes. We have never seen so many people at the same time,” says Jean-Charles Couillandre. Many of the weakest were never noticed. “It’s completely unique. We can clearly see that from a technical point of view Euclid works great,” comments David Elbaz.

Horsehead Nebula

This is a symbolic celestial object already photographed by Hubble. “Except that here we have a vision of the entire panorama,” emphasizes David Elbaz. We especially admire the blue cloud above the horse’s head, which we don’t see in the Hubble image. This is due to ionized hydrogen gas. This is interesting because hydrogen is the most abundant element in the universe, and when it ionizes, we know it means stars are born. This light is a little like the first cry of newly born stars. “The astrophysicist adds that the red dust is, on the contrary, the remains of dead stars, and the intense light source at the bottom left is a nursery for stars that were actually born. “In one image we see three stages in the life of these stars. »

Spiral Galaxy IC342

It is sometimes called a “hidden galaxy”, due to its apparent proximity to the stars, clouds of gas and dust of our own Milky Way galaxy, which can make it difficult to observe. “This galaxy IC342 is surrounded by an extraordinary number of stars in the Milky Way. This image is a testament to the technical excellence of the telescope. It’s a bit like photographing a cat through the leaves of a hedge,” illustrates David Elbaz. “I have never seen so much detail in an image. I think this is the best portrait of the galaxy ever made,” enthuses Jean-Charles Couillandre. “When you look at Euclid images, there is information in each of the pixels. »

Globular cluster NGC 6397.

These are stars bound to each other by gravity. “We are here, in the very fabric of our own galaxy. In one image we wanted to show the crystal clear aspect of Euclid’s images,” comments Jean-Charles Couillandre. “There are 400,000 stars concentrated in this globular cluster. We see them individually, we see their colors! “, David Elbaz is surprised. “Some say that it is at the core of this type of structure that intermediate black holes are born. These globular clusters are believed to have arisen from the collision of galaxies. »

Irregular galaxy NGC 6822.

Galaxy, right? “You’d think it was a cluster of stars,” admits David Elbaz. “This is the closest galaxy to us, not counting the satellites of the Milky Way. “It is also possible that it was distorted after passing too close to our galaxy. NGC 6822 was also immortalized by the James Webb Space Telescope. “Here we can see each star individually, even the dimmest,” says Jean-Charles Couillandre.