Massive star clusters break free from birth clouds in 5 million years, reshaping galaxy growth models
NASA/ESA observations with Webb and Hubble identified ~9,000 young star clusters in four nearby galaxies, revealing that the most massive clusters clear their birth gas in about 5 million years, while smaller clusters take roughly 7–8 million years. This challenges the simple expectation that bigger clusters clear faster and provides a sharper clock for how stellar feedback heats and pushes gas, influencing galaxy evolution models and the potential role of early massive clusters in cosmic reionization. The result tightens constraints for simulations of star formation and feedback and has implications for planet-forming disks in dense cluster environments. Future work will expand the survey to more galaxies and distant systems to test if local trends scale to the early universe.
