James Webb finds planet-forming ingredients in most common star type

New research using data from the James Webb Space Telescope (JWST) has analysed hundreds of low-mass stars and found planet-forming dust surrounding them.

“Low-mass stars are the most numerous stellar objects in the Universe,” the international team of researchers write in their new paper.

“Before the JWST, we had limited knowledge of how planetary systems around low-mass stars could form at subsolar metallicities.”

For scientists, metallicity is not just metals, but the abundance of any element bigger than hydrogen or helium – these are the elements which help form space dust. This dust eventually produces planets. 

The new research looked at a star-forming region called NGC 346 in the Small Megallanic Cloud which neighbours our galaxy, The Milky Way.

This part of the Small Megallanic Cloud is quite low in ‘metal’ elements, such as silicon, magnesium, aluminium, and iron which clump into planets. 

Fig 1 ngc 346
NIRCam mosaics of NGC 346. Credit: Jones et al., Nature Astronomy, 2023.

The researchers used the JWST’s infrared abilities to be able to peer deep into NGC 346 – looking at the main arc of the cluster, as well as the middle-aged BS90 cluster towards the top of the image, and the young stars in the middle.

The researchers found infrared ‘excesses and accretion’ – or in non-science terms, dust – close to the low-mass stars.

This is exciting for NGC 364, but also has implications for much older stars and planets. The researchers believe that the amount of these larger elements in NGC 346 is about the same as ancient galaxies.

This means that these ancient galaxies – which were formed around 11 to 12 billion years ago – could also have been producing planets around this time.

Jwst ngc 346
NGC 346 taken by the James Webb Space Telescope’s Near-Infrared Camera.

“Our survey reveals a population of dusty, subsolar mass young stellar objects and represents the deepest extragalactic census of these objects at low metallicity,” the researchers write.

“The discovery of an associated infrared excess in these objects reveals substantial dust around low-mass young stellar objects … suggesting that the material to form rocky planets is present at this low metallicity.”

The research has been published in Nature Astronomy.

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