The cluster appears here as a large collection of brilliant white lights, each a distinct galaxy. A neon purple cloud stretches across the cluster's crowded core. Many of the hundred-plus galaxies in the cluster are in two clumps of galaxies towards the top and bottom of center. Some are encircled by a faint glowing haze, while a few foreground stars gleam with diffraction spikes. Some of the smaller galaxies are tinted blue, orange, or red, and some appear more oblong than round, suggesting spiral shapes viewed edge-on.
The neon purple cloud sits at the heart of the image, surrounding the most densely-packed part of the cluster. This cloud, which spreads vertically across the cluster, is multimillion-degree gas observed by Chandra. The two clumps of observable galaxies, and the spread of superheated gas, reveal that the Champagne Cluster is in fact two clusters in the process of colliding.
With the two clusters of sparkling light clinking together, and the auspicious discovery date, astronomers have dubbed the merged cosmic structure "The Champagne Cluster".
Astrophysics Group Rings in New Year With Champagne Cluster
Prof. Wittman's research group's work on a merging galaxy cluster was highlighted by a NASA press release. The group was working on identifying clusters that are undergoing major mergers when, a few years ago on December 31, they found this excellent candidate and Wittman told his collaborator "You can have some Champagne tonight!" The nickname stuck as the group obtained follow-up observations with the Keck Observatory and the Hubble Space Telescope. These new results were published in 2025, and described in a December 30th 2025 press release from NASA.
In the image above, X-rays from NASA's Chandra X-ray Observatory outline the distribution of hot gas. The gas is elongated, with a cluster of galaxies at either end. This indicates that the clusters have passed through each other and partially dislodged the gas. Further study of clusters in this rare state can probe the response of dark matter to such a collision.