Credit: ESA/Euclid/Euclid Consortium/NASA, CFHT, image processing by J.-C. Cuillandre and E. Bertin (CEA Paris-Saclay)

This six-gigapixel view of the galactic bulge is the largest high-resolution photo ever made of our Milky Way galaxy’s centre in visible light. It was taken on 23 March 2025 by the European Space Agency’s Euclid space telescope.

This version shows the full survey area, with edge effects from the 3x3 pointing pattern of Euclid's visible camera.

The galactic bulge – the central region of our galaxy – is a vast, tightly packed structure filled mainly with old, cooler stars, giving it its characteristic yellow color. Seen from some 26 000 light-years away, Euclid observes the galaxy’s centre through a complex foreground of material along its line of sight.

This ultra-wide view towards the bulge reveals not only stars, but also seemingly empty dark regions. The dark patches are not devoid of stars: they mark dense, dust-rich molecular clouds that absorb and scatter light from the bulge behind them. As Euclid looks through two of the Milky Way’s spiral arms, it also encounters regions of active star formation, traced by newly formed, massive blue stars. Their intense ultraviolet radiation ionises surrounding hydrogen gas, producing the faint red glow clearly visible in one region.

Euclid covered 4.8 square degrees of the sky with this image, corresponding to 22 times the area of the full Moon as seen from Earth. The image has been rotated counterclockwise compared to the celestial projection: north is to the left and east is down.

Technical details: The Euclid galactic bulge survey was conducted in early 2025 using Euclid’s optical camera VIS (monochromatic, one color). These are first and foremost Euclid images, defined by Euclid’s crisp resolution and spectacularly wide field of view; the colors were added using observations captured in the summer of 2025 with the Canada-France-Hawai'i Telescope’s MegaCam camera (CFHT-Megacam) in Hawai’i. The colors captured by MegaCam are in optical light through three broad-band filters (u, g, and r) overlapping the very broad VIS band over the r-band. The appearance of the most luminous stars in these images looks different than those generated from Euclid-only images, with additional diffraction spikes and a subtle halo around the very bright stars. This a consequence of combining Euclid VIS data, for their sensitivity and sharpness, and CFHT-MegaCam for the colors. Subtle differences in optical design of the two telescopes become apparent for the brighter objects.

Provider: Euclid

Image Source: https://euclid.caltech.edu/image/euclid20260624a-euclid-s-galactic-bulge-survey

Curator: ESA/Euclid

Image Use Policy: CC BY-SA 3.0 IGO