The Chandra X-ray Observatory has significantly expanded its cosmic data repository, now boasting over 1.3 million individual X-ray detections. This milestone was announced on January 25, 2026, with the release of the latest version of the Chandra Source Catalog (CSC), which includes data collected up to the end of 2020. The catalog serves as an essential resource for astronomers, enabling a deeper understanding of the universe.
The CSC version 2.1 comprises more than 400,000 unique sources, both compact and extended. It includes detailed information such as precise positions in the sky and the specific X-ray energies detected. This comprehensive dataset allows astronomers using various telescopes, including NASA’s James Webb and Hubble Space Telescopes, to integrate Chandra’s unique X-ray data with other observational data.
Insights from the Galactic Center
One of the most striking examples of the catalog’s utility can be seen in a recent image of the Galactic Center, the region surrounding the supermassive black hole known as Sagittarius A*. Within this area, spanning approximately 60 light-years, Chandra has detected over 3,300 individual sources emitting X-rays. This remarkable image is the result of combining 86 observations and represents more than three million seconds of observing time.
Additionally, a newly released sonification project translates 22 years of Chandra observations into sound, providing a novel way to experience the data. This audio representation illustrates the frequency of X-ray detections over time, with different notes signifying multiple observations of the same source. The visual component of this project presents the sky in a way similar to traditional world maps, placing the core of the Milky Way at the center.
Continuing Discoveries
As the Chandra X-ray Observatory remains fully operational, the catalog will continue to grow. The text in the sonification video emphasizes this ongoing effort, changing to “…and beyond” after 2021 to reflect future observations. Throughout the video, a collage of images produced by Chandra complements the evolving sky map, showcasing the vast array of data collected throughout its mission.
Researchers and enthusiasts interested in exploring the Chandra Source Catalog can access the latest version online at https://cxc.cfa.harvard.edu/csc/. As astronomers delve into this extensive database, the potential for new discoveries about our universe continues to expand, highlighting the enduring legacy of the Chandra X-ray Observatory.