James Webb Space Telescope Discovery

Peeking into Perseus

This stunning new mosaic of images from the NASA/ESA/CSA James Webb Space Telescope showcases the nearby star-forming cluster, NGC 1333. The nebula is in the Perseus molecular cloud, and located approximately 960 light-years away. Webb’s superb sensitivity allows astronomers to investigate young objects with extremely low masses. Some of the faintest ‘stars’ in the picture are in fact newly born free-floating brown dwarfs with masses comparable to those of giant planets. The same cluster was featured as the 33rd anniversary image of the NASA/ESA Hubble Space Telescope in April of 2023. Hubble’s image just scratched the surface of this region, because clouds of dust obscure much of the star formation process. Observing with a larger aperture and in the infrared part of the spectrum, Webb is capable of peering through the dusty veil to reveal newborn stars, brown dwarfs and planetary mass objects. The centre of the image presents a deep peek into the heart of the NGC 1333 cloud. Across the image we see large patches of orange, which represent gas glowing in the infrared. These so-called Herbig-Haro objects form when ionised material ejected from young stars collides with the surrounding cloud. They are hallmarks of a very active site of star formation. Many of the young stars in this image are surrounded by discs of gas and dust, which may eventually produce planetary systems. On the right hand side of the image, we can glimpse the shadow of one of these discs oriented edge-on — two dark cones emanating from opposite sides, seen against a bright background. Similarly to the young stars in this mosaic, our own Sun and planets formed inside a dusty molecular cloud, 4.6 billion years ago. Our Sun didn’t form in isolation but as part of a cluster, which was perhaps even more massive than NGC 1333. The cluster in the mosaic, only 1–3 million years old, presents us with an opportunity to study stars like our Sun, as well as brown dwarfs and free-floating planets, in their nascent stages. Credit: ESA, NASA, CSA, STScI Peeking into Perseus Peeking into Perseus (wide field view)