Rubin Observatory's first LSST Camera release: 500k galaxies in the COSMOS field

**NSF–DOE Vera C. Rubin Observatory** released its first **LSST Camera** science image and catalog on **July 31, 2026**, covering the **COSMOS** field in the constellation **Sextans**. The release packs roughly **500,000** distant galaxies into a single deep view of one of the most observed patches of sky. It is the observatory’s first LSST Camera product opened for science use, not only a public preview.

The frame is galaxy-dominated: spirals with resolved arms, smooth ellipticals, merging systems, and faint red objects at large distance fill the field, while only a small number of bright **Milky Way** stars sit in the foreground. That low stellar clutter leaves an unusually clean line of sight through COSMOS and supports catalog work on morphology, mergers, and faint red populations in one cut. The product is both a deep image and a science catalog tied to the first LSST Camera release path.

For engineers and builders, the story is scale plus a known calibration field. COSMOS already carries multi-wavelength history; a new deep Rubin layer on the same coordinates is a natural place to test pipelines, cross-match catalogs, and stress photometric and morphological classifiers on hundreds of thousands of real objects. The first public LSST Camera science catalog also sets a concrete interface for tools that will later face full-survey volume.

COSMOS has long been a shared reference field across facilities. Rubin’s first LSST Camera science image and catalog on that landmark add a wide, deep optical layer next to prior surveys rather than opening an empty field. That places the release at the intersection of legacy multi-mission work and the start of LSST Camera science products under the NSF–DOE Rubin program.

Watch how this COSMOS image and catalog are used as the reference sample for later LSST Camera releases: morphology labels, faint-red selection, and merge samples drawn from the ~500k galaxies will show whether the first science cut is clean enough to anchor automated analysis. Next milestones are expansions beyond this single famous field and whether subsequent catalogs keep the same depth and foreground clarity at larger sky area.