The James Webb Space Telescope (JWST) has solved a long-standing puzzle in cosmology by observing stars in the Small Magellanic Cloud with planet-forming disks that are longer-lived than expected. The findings contradict accepted models of planet formation, which suggest that planets around young stars should dissipate quickly due to the limited availability of heavy elements.
The study, led by Guido De Marchi, used JWST’s high-resolution spectrometers to observe young Sun-like stars and their environments in a nearby galaxy. Unlike earlier observations by Hubble, which revealed protoplanetary disks around many young stars in the cluster NGC 346 (~20 to 30 million years old), JWST found that these disks persist for longer than previously thought.
According to accepted cosmological models, the first stars in the Universe (Population III stars) formed 13.7 billion years ago and were composed of hydrogen and helium with little heavy elements. These elements were forged in the interiors of Population III stars and distributed throughout the Universe once they exploded in supernovae.
The JWST findings suggest that planet formation may occur earlier than predicted, as planets have more time to form and grow around young stars like those observed in NGC 346. Researchers propose two mechanisms that could explain these observations: a star’s radiation pressure only being effective with sufficient heavy elements present in the disk or a larger cloud of gas needed for a Sun-like star to form.
The study provides strong confirmation of JWST’s capabilities, confirming earlier Hubble findings and challenging current models of planet formation. The discovery has significant implications for how astronomers understand the early Universe and how planets are formed.
Source: https://www.universetoday.com/170133/webb-observes-protoplanetary-disks-that-contradict-models-of-planet-formation