Webb and Hubble confirm Terzan 5 as bulge fossil fragment (esa.int)

• Terzan 5 classified as bulge fossil fragment, not globular cluster
• Four stellar generations dated: 12.5, 4.7, 3.8, and 2.5 billion years ago
• Combination of Webb infrared and Hubble proper motion data

"Researchers using the James Webb Space Telescope and Hubble Space Telescope have confirmed Terzan 5 is not a globular cluster but a 'bulge fossil fragment'—a relic from the Milky Way's formation. The cluster contains four distinct stellar generations, indicating it retained gas for star formation over billions of years. This makes Terzan 5 a prototype for understanding galaxy bulge formation."