The image, created by combining hundreds of observations from the LSST camera, also contains more than 50 stars. Its release is accompanied by the observatory's first science catalog based on the giant camera, as part of a preview of data collected between April 2025 and January 2026.
Vera C. Rubin Observatory published a deep image of COSMOS Field, one of the most studied regions in the sky, with more than half a million galaxies and over 50 stars. The image was created from a combination of hundreds of observations made by a camera LST It is 3.2 billion pixels old, and is accompanied by the first publication of an image and scientific catalog from the camera.
This is not the first image that the Rubin Observatory has released to the public. The first experimental images were released in 2025, and the ten-year scientific survey began operating in June 2026. The importance of the new publication is that it is part of a data release intended for scientific work: the EDP2 Early Data View, which is based for the first time on observations fromLSST camera The full.
The image shows a wide variety of galaxies: spiral galaxies with prominent arms, smooth elliptical galaxies, distorted systems in the process of merging, and faint red galaxies whose light has been lost billions of years ago. The number of bright stars from the Milky Way is relatively small because the COSMOS field is located far from the dense, dusty plane of our galaxy.
A familiar window into the distant universe
The COSMOS field is located in the constellation Sextant. Astronomers have been studying it for more than two decades, since the Hubble Space Telescope began observing it in 2003. Many other telescopes, from radio to X-ray, have since been directed at the same region, including the James Webb Space Telescope, Spitzer, Chandra, and XMM-Newton, as well as large ground-based observatories.
Choosing a region that has been studied repeatedly is no coincidence. Combining data from different wavelengths allows researchers to compare the mass of stars in a galaxy, its dust and gas, the rate of star formation, the activity of black holes, and the environmental structure in which the galaxy is located.
The wealth of data already collected on COSMOS also makes the field a suitable calibration and testing site for a new system. Researchers can compare Rubin's measurements to existing catalogs, check the accuracy of the brightness and location of objects, and test how well the system can detect faint galaxies.
The Rubin Observatory has a different advantage than Hubble or Webb. Space telescopes typically provide high-resolution, deep observations in relatively small fields. Rubin is built to combine depth, wide-sky coverage, and repeat imaging. It will not only see what objects are in the field, but also record how they change over time.
3.2 billion pixel camera
The image was taken using the LSST camera, which is mounted on the 8.4-meter-diameter Symoni Survey Telescope. The camera, built at the National Accelerator Laboratory SLAC, is considered the largest digital camera built for astronomy.
The color image is not a single exposure. It was created by combining hundreds of photographs taken at different times and with different filters. Combining the observations increases the signal-to-noise ratio and makes it possible to identify galaxies that are too faint to appear clearly in a single image.
Repeated photography plays another role. When comparing images of the same field from different times, it is possible to detect objects that have changed their brightness or position – including supernovae, variable stars, active galactic nuclei and asteroids passing in the foreground of the image.
According to Bob Bloom, the operations manager of the Rubin Observatory inNOIRlabThe deep image is just the beginning of the work in the COSMOS field. Return visits to the region are expected to reveal a large number of transient events and variable objects, after which other telescopes will be able to make detailed follow-up observations.
Data display – not yet the full survey
The image was released as part of the first phase of Early Data Preview 2, or EDP2. This dataset combines science validation observations collected between April 2025 and January 2026, before the LSST survey begins full operation.
The data release includes detailed, detailed images of regions that together cover about 3,000 square degrees—about one-sixth of the visible southern hemisphere sky. In addition to COSMOS, it also includes the “Ocean of Stars” region, which was imaged when the survey was launched.
The second phase of EDP2, scheduled for October to December 2026, will add processed images from single observations, reference images, and difference images. In a difference image, a reference image of the same region is subtracted from a new observation, leaving behind mostly the changed objects – a key tool for rapidly detecting supernovae and other astronomical events.
EDP2's scientific data is currently available to licensed researchers in the United States and Chile and to international data rights holders. According to the observatory's policy, the data sets will be opened to the public after a two-year ownership period. The image itself is publicly available and can be explored using the Rubin Skyviewer app.
Deep field in a ten-year-old film
COSMOS is one of the deep fields that the LSST survey will observe more frequently than most of the sky. As more observations are collected, the combined image will become deeper, revealing faint galaxies and details that were not visible in the first release.
At the same time, the Rubin Observatory will scan the southern sky every few nights for ten years. The planned result is not just a static map, but a long sequence of observations – a kind of movie of the changing universe. The data will be used to study dark matter וdark energy, the evolution of galaxies, variable stars, stellar explosions and objects in the solar system.
The scientific value of the current image does not stem solely from the number of galaxies in it. It stems from the possibility of returning to the same field again and again and combining the new data with more than twenty years of observations from other telescopes. In this way, COSMOS transforms from a kind of vast group photograph of galaxies into a laboratory in which it is possible to track changes in the universe over time.
Questions and Answers
Is this the first photo of Mitzpe Rubin?
No. The observatory published experimental images as early as 2025. This is the first publication of a scientific image and catalog based on the full LSST camera as part of EDP2.
How many objects appear in the picture?
According to the Rubin Observatory, the image contains more than half a million galaxies and more than 50 stars.
Why is the COSMOS field important to astronomers?
This is a region that has been observed for more than twenty years in a wide range of wavelengths. The existing data allows for comparison of measurements and the integration of observations from different telescopes.
What will the Rubin Observatory add to the previous observations?
Rubin will combine deep and wide imaging with repeated observations. This will allow us to study both the structure of galaxies and events and changes that occur in the field over time.
More on the subject on the science website
- The Rubin Observatory's giant camera is underway, and its goal is: "To answer one question - what is the universe?"
- James Webb Space Telescope reveals sharpest map of the cosmic web
- Vera Rubin Observatory begins operations and has already discovered more than 11 new asteroids
- Visitors from distant stars: Rubin Observatory will detect a wealth of interstellar objects
- Vera Rubin, the astronomer whose measurements provided crucial evidence for the existence of dark matter
For the original publication: [NSF–DOE Rubin Observatory Opens Deep Window on Famous Cosmic Field] (Vera Rubin Observatory and NSF NOIRLab, July 31, 2026.
