Gallery: Euclid Telescope’s Early Images Hint At Discoveries To Come

Many telescopes have taken images of the Horsehead Nebula, also known as Barnard 33 and located about 1,375 light-years from Earth in the Orion constellation, but none has been able to produce one as sharp and wide-angle as Euclid did with just a single observation. Scientists hope to find young, previously unseen Jupiter-mass planets, brown dwarfs and baby stars in the nebula, which is the closest giant star-formation region to Earth.

Euclid captured light from 1,000 galaxies in the Perseus Cluster—and 100,000 more galaxies in the background, many of which were previously unseen. Perseus, located about 240 million light-years from Earth, is one of the most massive structures known in the universe, containing thousands of galaxies immersed in a vast cloud of hot gas. Studies show that galaxy clusters like Perseus could not have formed without the gravitational pull of dark matter. “If no dark matter existed, galaxies would be distributed evenly throughout the universe,” notes Euclid Consortium scientist Jean-Charles Cuillandre, who works with the CEA Paris-Saclay in France.

In a powerful demonstration of its imaging capabilities, Euclid became the first telescope to capture an entire globular cluster in a single observation while simultaneously providing a sharp enough view to distinguish individual stars in the cluster. NGC 6397 is the second-closest globular cluster to Earth, located about 7,800 light-years away. Among the studies: a search for what are known as “tidal tails”—trails of stars extending far beyond the cluster due to a previous interaction with another galaxy. If there are no tidal tails, a dark-matter halo could exist around the cluster, preventing outer stars from escaping. “We don’t expect dark-matter halos around smaller-scale objects like globular clusters, only around bigger structures like dwarf galaxies or the Milky Way itself,” notes Euclid Consortium scientist Davide Massari of Italy’s National Institute for Astrophysics.

The early universe was predominantly populated by small, irregularly shaped galaxies, but some of these, such as NGC 6822, exist relatively close to Earth, just 1.6 million light-years away. Discovered in 1884, the galaxy is a member of the same cluster as the Milky Way—the so-called Local Group. Euclid imaged the entire galaxy and its surroundings in high resolution in about 1 hr. Globular clusters are collections of hundreds of thousands of stars held together by gravity. They are some of the oldest objects in the universe, and most of their stars were all formed out of the same cloud.

In one of its first observations of a galaxy, Euclid took an infrared image of IC 342, or Caldwell 5, which appears to be a twin of our own Milky Way. The galaxy, 11 million light-years from Earth, is located behind the disc of the Milky Way, so the view is obscured by dust, gas and stars. Euclid’s infrared optics can peer through the dust to image the spiral’s cool, low-mass stars. “What’s so special here is that we have a wide view covering the entire galaxy, but we can also zoom in to distinguish single stars and star clusters. This makes it possible to trace the history of star formation and better understand how stars formed and evolved over the lifetime of the galaxy,” says Euclid Consortium scientist Leslie Hunt of the National Institute for Astrophysics in Italy.