Euclid telescope captures 60 million stars in the most detailed visible-light image of the Milky Way’s centre

The European Space Agency’s Euclid telescope, launched in July 2023 to map the dark universe, has delivered an unexpected gift: the most detailed visible-light portrait of the Milky Way’s crowded heart. On 23 March 2025, the telescope spent just over a day staring at the galactic bulge and stitched together a mosaic of nine pointings, each larger than the full Moon, to reveal more than 60 million stars. The image was released on 24 June 2026.

A single-day pivot to the brightest sky

Euclid normally peers at deep cosmological fields, but astronomers persuaded the mission to aim at the brightest region of the galaxy for one day. The visible-light camera’s sensitivity proved equal to the challenge, separating individual stars in the super-crowded bulge without being saturated.

“We’ve decided to point Euclid at the brightest area of the sky — and it works superbly, it’s extraordinary.”

The 26-hour observation produced a mosaic whose total field of view is roughly 270 times larger than a Hubble Wide Field Camera frame, yet with comparable sharpness. Dark patches threading the image are dense molecular clouds that absorb and scatter background starlight.

Exoplanet hunting with a cosmic magnifying glass

Microlensing occurs when one star passes almost directly in front of another; the nearer star’s gravity bends and brightens the light of the background star. If a planet orbits the foreground star, its gravity adds a tiny extra brightness variation. Euclid’s bulge image includes 51 known planetary systems and will let astronomers measure the mass of exoplanets long after their initial detection.

“During the last 20 years, almost 300 exoplanets have been discovered using this technique, all with ground-based telescopes and all towards the centre of our galaxy.”

The image gives scientists a baseline against which future brightness changes can be compared.

“Statistically, we should be able to find some exoplanets among all those stars.”

What the image reveals beyond the stars

The mosaic’s width and depth also expose the structure of the bulge itself, a vast bubble of old, cool stars that gives the galaxy’s centre its characteristic yellow hue. The nine original frames were captured in black and white; colour was added using observations from the Canada-France-Hawaii Telescope. Future international collaborations will use the dataset to revisit known phenomena and potentially identify new worlds.

The image is now publicly available and will serve as a resource for astronomers worldwide hunting for planets, studying stellar populations, and mapping the dense inner regions of the Milky Way.