Location of Euclid’s galactic bulge survey

The location of Euclid’s new image of the galactic bulge is visible on Gaia’s map of the entire sky.

Two zooms show the staggering resolution of Euclid’s image. The most zoomed-in vignette on the lower right corresponds to 0.003% of the galactic bulge survey area (which is 4.8 square degrees in total). With many thousands of stars discernible in this tiny area, the entire Euclid galactic bulge image charts no less than 60 million stars.

Read more about this image here.

[Image description: A wide, horizontal image shows an oval, map-like view set against a black background. Across the centre of the oval runs a bright, narrow band filled with countless tiny points of light, denser and brighter than the areas above and below it. The band looks slightly mottled, with lighter and darker patches mixed together, similar to a thin stripe of dust or mist stretched across a surface. Several rectangular zoom-in panels are overlaid on the main image, showing close-up views of densely packed stars in yellow, gold, and darker tones.]

Technical details:

The Euclid galactic bulge survey was conducted in early 2025 using Euclid’s optical camera VIS (monochromatic, one colour). These are first and foremost Euclid images, defined by Euclid’s crisp resolution and spectacularly wide field of view; the colours 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 colours 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 colours. Subtle differences in optical design of the two telescopes become apparent for the brighter objects.