New telescope images uncover ‘Green Monster’ in Cassiopeia A

Using NASA’s James Webb Space Telescope, astronomers uncovered a mysterious feature within the remnant, nicknamed the “Green Monster,” alongside a puzzling network of ejecta filaments forming a web of oxygen-rich material. When combined with X-rays from NASA’s Chandra X-ray Observatory, the data helped astronomers shed light on the origin of the Green Monster and revealed new insights into the explosion that created Cas A about 340 years ago, from Earth’s perspective.

Like with the Cygnus Loop, Chandra has provided a 3-dimensional (3D) printable model that can be used to explore the end stage of a star’s life. These 3D models are based on state-of-the-art theoretical models, computational algorithms, and observations from space-based telescopes like Chandra that give us accurate pictures of these cosmic objects and how they evolve over time.