James Webb Space Telescope (JWST) research, supported by Hubble Space Telescope (HST) data, is revealing exciting new information about star and planet formation from observations of four nearby galaxies.
In these galaxies, researchers observed thousands of young stars in different clusters at various stages of evolution, according to a recent paper published in Nature Astronomy. The main takeaway from the JWST and HST research is that the more massive a star cluster is, the faster it pushes its natal gas away, allowing it to emerge from its cloud, at the expense of planet formation.
Galactic Evolution
At the heart of galactic evolution are star clusters, clouds of gas from which stars coalesce under gravitational forces. Over time, stars produce radiation, stellar winds, and supernovae that disperse these natal clouds, ending the period of star formation and leaving residual gas to drift through space. Once the gas is cleared, light from the stars can propagate more freely throughout the galaxy in a process known as stellar feedback, pushing away additional gas before it can be used to form new stars.
Astronomers have managed to observe a handful of local star-forming regions within our galaxy and nearby dwarf galaxies, but our vantage point provides only a limited view. Nearby galaxies offer better opportunities to survey star-forming regions and star clusters with the JWST and HST. By combining observations from both within and beyond our galaxy, astronomers can assemble a broader dataset that allows for deeper analyses of star formation.
JWST Peers Out at the Cosmos
Infrared instruments like those aboard the JWST have been essential for understanding star-forming clouds, allowing researchers to peer through their dense gas and dust and glimpse what lies within.
Behind that gas, some of the earliest stages of star cluster development are taking place, offering new insight into the beginnings of galaxies. One of the biggest unresolved questions has been how long it takes for a cloud to disperse, allowing the light from a star cluster to escape into the wider galaxy.
The combined observations from HST and JWST provide the broadest spectral view of young star clusters astronomers have ever obtained. The galaxies at the center of the recent study are Messier 51, Messier 83, NGC 628, and NGC 4449. After an international team of researchers analyzed images captured by the two space telescopes, they concluded that the more massive a star cluster is, the faster it clears away its gas.
9000 Clusters Before the JWST
In these galaxies, researchers identified nearly 9,000 star clusters at various evolutionary stages, ranging from fully obscured by natal gas clouds to completely cleared, with intermediate stages in between. JWST’s infrared capabilities revealed partially or fully obscured clusters, while Hubble’s visible-light instruments showed those that had already cleared their natal clouds. The timescale for dispersing natal gas clouds ranged from about five million years for the most massive clusters to as long as eight million years for less massive ones.
“Simulations of star formation and stellar feedback have struggled to reproduce how star clusters form and emerge from their natal clouds. These results give us important new constraints on that process,” explained lead author Angela Adamo of Stockholm University and the Oskar Klein Center in Sweden.
Researchers already knew that massive star clusters emitted most of a galaxy’s ultraviolet light, but the new findings also demonstrate that they begin dispersing that light earlier than smaller clusters. By tracking how stellar feedback waxes and wanes across different parts of a galaxy, researchers can better understand how it redistributes essential star-forming gas.
Ironically, the faster dispersal of natal clouds in massive clusters may undermine planet formation by exposing protoplanetary disks to ultraviolet radiation earlier, reducing their ability to capture gas needed to form planets. In this way, some of the universe’s most massive star clusters may also impose severe limitations on planet formation, a phenomenon that has also been observed in our own Milky Way.
The paper, “The Emerging Timescale of Young Star Clusters Regulated by Cluster Stellar Mass,” appeared in Nature Astronomy on May 06, 2026.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.