Free Astronomy Magazine March-April 2025

MARCH-APRIL 2025 tive, elements heavier than hydro- gen and helium would have to re- side in the gas. But the massive star cluster NGC 346 only has about ten percent of the heavier elements that are present in the chemical compo- sition of our Sun. Perhaps it simply takes longer for a star in this cluster to disperse its disk. The second possibility is that, for a Sun-like star to form when there are few heavier elements, it would have to start from a larger cloud of gas. A bigger gas cloud will produce a big- ger disk. So there is more mass in the disk and therefore it would take longer to blow the disk away, even if the radiation pressure were work- ing in the same way. “With more matter around the stars, the accre- tion lasts for a longer time,” said Sabbi. “The disks take ten times longer to disappear. This has impli- cations for how you form a planet, and the type of system architecture that you can have in these different environments. This is so exciting.” !