NASA’s James Webb snaps photo of star cluster 200,000 light-years away

NASA’s James Webb Space Telescope (JWST) has released yet another new image, providing new insights into how stars formed in the early universe more than 10 billion years ago.

The image shows a young cluster of stars NGC 346, which is more than 200,000 light-years from Earth.

Located in the Small Magellanic Cloud (SMC) – a dwarf galaxy near the Milky Way – NGC 346 is interesting to astronomers because it resembles the conditions of the early Universe when star formation was at its peak.

Astronomers believe studying this region could help shed light on how the first stars formed during the ‘cosmic noon’, which is only two or three billion years after the Big Bang.

The SMC contains lower concentrations of elements heavier than hydrogen or helium, which astronomers call metals, compared to the Milky Way.

Since dust grains in space are composed mostly of metals, scientists expected there would be low amounts of dust, and that it would be hard to detect. 

However, the new data from Webb reveals the opposite.

‘A galaxy during cosmic noon wouldn’t have one NGC 346 like the Small Magellanic Cloud does; it would have thousands’ of star-forming regions like this one,’ said Margaret Meixner, an astronomer at the Universities Space Research Association and principal investigator of the research team. 

‘But even if NGC 346 is now the one and only massive cluster furiously forming stars in its galaxy, it offers us a great opportunity to probe conditions that were in place at cosmic noon.’

The NGC 346 houses protostars – clouds of gas and dust in space that are developing into stars. 

Previous infrared studies of the star cluster have focused on protostars heavier than about five to eight times the mass of our Sun. 

‘With Webb, we can probe down to lighter-weight protostars, as small as one tenth of our Sun, to see if their formation process is affected by the lower metal content,’ said Olivia Jones, Science and Technology Facilities Council Webb Fellow at STFC’s UK Astronomy Technology Centre.

As stars form, they gather gas and dust, which can look like ribbons in Webb imagery, from the surrounding molecular cloud. 

The material collects into an accretion disk that feeds the central protostar. 

Astronomers have detected gas around protostars within NGC 346, but Webb’s near-infrared observations mark the first time they have also detected dust in these disks.

Guido De Marchi, of the European Space Agency, and a co-investigator on the research team, said: ‘We’re seeing the building blocks, not only of stars but also potentially of planets.

‘And since the Small Magellanic Cloud has a similar environment to galaxies during cosmic noon, it’s possible that rocky planets could have formed earlier in the Universe than we might have thought.’

Researchers hope that observing protostars still in the process of forming will reveal whether the star formation process in the SMC is different from what we observe in our own Milky Way. 

Ms Jones added: ‘This is the first time we can detect the full sequence of star formation of both low and high mass stars in another galaxy.

‘This means we have far more data to study at high resolution, offering us new information on how the birth of stars shapes their environment and even greater insight into the star formation process.’



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