Rubin's COSMOS

This image from NSF–DOE Vera C. Rubin Observatory features a region of the sky known as the COSMOS field, one of the most observed patches of the Universe. Packed into this single view are a wide variety of galaxies: spirals with delicate arms, smooth ellipticals, distorted merging galaxies, and faint red galaxies from the distant Universe. Only a few bright stars from our own Milky Way appear in the foreground, giving us an unobstructed view of galaxies stretching far into the distance.

Beginning with Hubble in 2003, astronomers around the world have pointed different telescopes toward this same area, observing it in wavelengths ranging from radio waves to X-rays. In this new view of a familiar field, Rubin reveals more than 650,000 galaxies, and more than 75,000 stars.

Why this spot?

The COSMOS field is valuable for astronomy and astrophysics because it looks away from the crowded plane of our Milky Way galaxy (Rubin’s Ocean of Stars image, by contrast, showed the view looking closer to that plane). With relatively few nearby stars and clouds of dust obscuring the view, telescopes can see enormous numbers of distant galaxies, many so far away that their light has traveled for billions of years to reach Earth.

Looking deeper into space also means looking farther back in time, allowing scientists to study galaxies at many different stages of the Universe’s history.

If it’s been studied so much, why is Rubin joining the party?

By repeatedly imaging the COSMOS field with its wide field of view and highly sensitive camera, Rubin will complement these earlier observations by adding more detail and a dynamic view of this area. And because astronomers already know the field so well, it provides a great opportunity to compare Rubin’s observations with decades of previous data, and confirm that Rubin is delivering precise, high-quality measurements.

Because of its scientific value, the COSMOS field is among the regions that Rubin will observe more frequently than most areas included in the Legacy Survey of Space and Time. These added observations will create an even deeper view, revealing even fainter galaxies and finer details than we see now.

We invite you to explore this image further in Rubin’s Skyviewer, where you can use the menu to navigate between this and previously released Rubin images.