what the first shots of the Euclid mission show

Everything is going well for Euclid. Before focusing fully on its core business, namely the study of dark matter and dark energy, the European space mission gave its news by publishing the first images on Tuesday, November 7. So many photos which prove that his instruments work perfectly.

>> Space: understand everything about the mysteries of dark matter and dark energy, which the European Euclid mission has set out to study

These photographs “are even more beautiful and precise than we could have hoped, showing us many details that had not been seen in well-known areas of our neighborhood”, enthuses René Laureijs, member of the Euclid scientific team, in a press release. Franceinfo presents to you what these images show.

The Perseus galaxy cluster, one of the largest in the universe

The Perseus galaxy cluster, which is located very far from Earth (approximately 250 million light years), “is one of the greatest in the universe”note to franceinfo Giuseppe Racca, project manager on the Euclid mission. “This is the first time that we can capture this entire mass with just one exposure.”, that is to say a shot, he emphasizes. The previous images in this set were assemblies of several visuals.

“We can see in this image about 1,000 galaxies that belong to the Perseus cluster”, comments Giuseppe Racca. Behind, many other small galaxies are visible. These are very far away, up to 10 billion light years from Earth, he adds. In total, mission scientists counted 100,000 small galaxies in this image.

The Horsehead Nebula, sharper than ever

This nebula is located in our galaxy, in the constellation Orion, some 1,600 light years away. While it is easily observable and already very famous, Michael Kahn says he was touched when he discovered this image. “I’ve never seen it taken so clearly”he notes to franceinfo.

In the mass of gas and dust, a particularly bright area attracts attention, at the bottom left of the image. “Often, nebulae are gases that have been ejected by a dying star and will contribute to the formation of new stars. Nebulae are therefore places where stars are born”, explains Michael Kahn. A violent event on a star sends shock waves through the gases, he summarizes. The light circle visible in the image thus results from the propagation of these shock waves.

The globular cluster NGC 6397, a “graveyard” of stars

This globular cluster is located in our Milky Way galaxy, some 7,800 light years from Earth. It is made up of around 400,000 stars, according to ESO (the European Southern Observatory). The mass importance of NGC 6397 is formed mainly by hundreds of white dwarfs, according to CNRS researchers. White dwarfs are, in short, corpses of stars. One day, our Sun will become one.

The image produced by Euclid is significantly more detailed than that of the same object taken in 2004 and 2005 by the Hubble space telescope. If this venerable and essential tool has already scrutinized the center of NGC 6397 in detail, observing its surroundings in depth would require a lot of time. With Euclid, this can be done in just an hour, the project team emphasizes.

The galaxy IC 342, the “hidden galaxy”

Galaxy IC 342 is a spiral galaxy, like ours. Also called Caldwell 5, IC 342 is located near the Milky Way. Very luminous, it is however not observable from Earth: it is masked by the light emitted by the central plane of our galaxy and its “galactic bulb”. This is why she is nicknamed the “hidden galaxy”. If it were not placed like this, it would be one of the brightest in Earth’s sky, says the Hubble team.

Although hidden, IC 342 enjoys a certain popularity among astronomers. She was the subject of distinguished photos on the NASA blog in 2013, 2016, 2019 and 2022. No surprise, therefore, that she was one of the first subjects photographed by Euclid.

The dwarf galaxy 6822, neighboring the Milky Way

NGC 6822, also called Barnard’s Galaxy, is 1.6 million light years from Earth. Described as a dwarf and irregular galaxy, this galactic neighbor of the Milky Way is characterized by strong activity. Areas that appear purple in the image “reveal regions of active star formation, where hot young stars heat nearby gas clouds”explained the ESO during a previous publication of a photo of NGC 6822, in 2009. Barnard’s galaxy was observed more recently: the teams of the James Webb space telescope unveiled an image on September 23, and another in August.

The specificity of the James Webb telescope lies in the fact that it can point its instruments at a very precise area of ​​the sky and see very far away. For his part, Euclid excels in scanning the sky very widely.

These visuals transmitted by Euclid are rarities. Unfortunately, we should not get used to admiring images of this mission, because its primary objective is not to produce them. Indeed, the objects of Euclid’s study – distant galaxies undergoing deformation – are generally not very aesthetic, recognizes Giuseppe Racca. The most important thing to remember from these first images is that Euclid’s instruments work very well, and that they will therefore perhaps help to shake up cosmology. “Now we are ready to observe billions of galaxies and study their evolution over cosmic time”enthuses René Laureijs, member of the Euclid scientific team.