Astronomers have captured the most detailed view to date of the famous COSMOS field, revealing over half a million galaxies and 50,000 stars using the world’s most powerful digital camera. According to the Vera C. Rubin Observatory, the newly released image and accompanying catalog mark the first time the Legacy Survey of Space and Time (LSST) Camera – the most powerful digital camera in the world – produced an image and catalog for scientific research.
LSST Camera Captures Deep Window on the COSMOS Field
The newly released image was created by stacking hundreds of individual observations made by the 3.2-gigapixel LSST Camera mounted on the 8.4-meter Simonyi Survey Telescope, according to the Rubin Observatory. The resulting dataset contains more than half a million galaxies and over 50,000 individual stars. Captured as part of Rubin’s Early Data Preview 2 (EDP2), the data combines observations obtained between April 2005 and January 2026 during the facility’s science validation period.
According to observatory officials, the frame features a diverse array of galaxies, including barred spirals with arms, smooth ellipticals, faint red galaxies, and distorted merging galaxies. The visible stars belong to the Milky Way and lie along the line of sight. Observatories avoided the crowded plane of the Milky Way to prevent the galactic disk and interstellar dust from obscuring the view, allowing telescopes to peer further into space and back in time.
Decades of Cosmic Evolution Survey Observations
Astronomers have studied the Cosmic Evolution Survey (COSMOS) field for more than two decades, utilizing leading telescopes across optical, radio, ultraviolet, and X-ray wavelengths, according to the Rubin Observatory. First photographed by the Hubble Space Telescope’s Advanced Camera for Surveys between 2003 and 2005, the region has served as a primary reference point for testing new instruments and comparing measurements.
Did you know? The COSMOS field covers a patch of the sky located in the constellation Sextans and was chosen because it looks away from the dense dust and gas of the Milky Way, offering an exceptionally clear view of the distant universe.
Rubin adds a dynamic perspective to this heavily studied landmark. “The COSMOS field is a very important one for LSST science,” said Phil Marshall, Deputy Director of Rubin Observatory at the SLAC National Accelerator Laboratory. Marshall noted that the field’s prior observations and repeated targeting make it a valuable testing ground for scientists preparing for full survey data.
Preparing for the Ten-Year Legacy Survey of Space and Time
While EDP2 represents a preliminary phase rather than the full ten-year survey, the data holds immediate scientific value. According to the Rubin Observatory, the release provides a deep co-added image covering 3,000 square degrees of the Southern Hemisphere sky, representing about one-sixth of the visible sky from that viewpoint.
“The COSMOS deep image is just the beginning for Rubin in this region,” said Bob Blum, Director of the Rubin Observatory at NSF NOIRLab. Blum explained that repeated visits will provide the science community with numerous transient and variable objects, such as supernovae, for detailed follow-up study.
Observatory leadership also acknowledged regional impacts during the release. Blum noted that the team’s thoughts remain with staff and communities in Chile affected by recent storms in Coquimbo. The institute dedicated the LSST science preview image to the people of the Coquimbo region in gratitude for decades of local support for astronomy and AURA Observatories.
Frequently Asked Questions
What is the COSMOS field?
The COSMOS field, or Cosmic Evolution Survey Deep Field, is a well-studied patch of the universe located in the constellation Sextans that has been observed by major space- and ground-based telescopes for over twenty years.
What is the LSST Camera?
The LSST Camera is a 3.2-gigapixel digital camera built for the Vera C. Rubin Observatory, jointly funded by the U.S. National Science Foundation and the U.S. Department of Energy’s Office of Science.
What does EDP2 stand for?
EDP2 stands for Early Data Preview 2, which is the first phase of Rubin’s Data Preview 2 release combining science validation observations obtained between April 2005 and January 2026.
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