A new infrared view of the star-forming region NGC 7129 shows young stars at markedly different stages of development, from still-forming protostars to a more evolved star already shaping a broad cavity in surrounding gas.
The region lies about 3,300 light-years from Earth. The image, captured with the James Webb Space Telescope’s Near-Infrared Camera, peers through dusty material that can obscure young stellar objects at other wavelengths. The institutional release describes the view as a detailed look at how stars interact with their environment, rather than announcing a new discovery about the nebula.
At the centre of the scene is LkH(alpha) 234, a luminous pre-main-sequence star estimated to have between five and eight times the Sun’s mass. A pre-main-sequence star has gathered most of its material but is still contracting under gravity; it has not yet begun the sustained hydrogen fusion that powers a mature star like the Sun.
To the left of this central object, the image shows a golden cavity extending roughly 3.5 light-years. The release explains that outflows from an earlier phase of the star’s life have pushed into the surrounding dense molecular cloud. Energy from both the outflows and the star illuminates the gas, while some material has been swept away and some compressed. That compression can create conditions favourable to the formation of additional stars, although the image itself is not evidence that a particular new star has formed there.
Several other stars appear within the cavity. Some are also in the pre-main-sequence stage and produce stellar winds. Where those winds encounter surrounding gas, they create curved bow shocks and smaller cavities. Along the cavity’s upper edge, heating from the central and embedded stars forms a boundary between hot material and colder, denser molecular gas. In this photodissociation region, hydrogen molecules are broken apart into atoms. The process affects local temperature and chemistry as the cloud gradually erodes over millions of years.
On the right-hand side, dense, clumpy material glows red and conceals younger objects: protostars. These are earlier in their development, still accumulating matter after clouds of gas and dust have compressed and fragmented. As they grow, they eject streams of superheated material. Those outflows strike nearby dense matter, generating shocks that give the region its textured appearance. Several overlapping flows contribute to the complex pattern seen from Earth.
Another set of outflows appears near a blue-coloured nebula at the upper left. A protostar sits at the centre of that region, surrounded by a disc of material. The disc casts a shadow across the surrounding nebula, a structure reminiscent of a feature observed in another star-forming setting by the Hubble Space Telescope.
The image’s different colours distinguish structures and physical conditions; they are not a view of visible-light colours as a human eye would see them. Infrared sensitivity and sharp spatial detail allow Webb to reveal material hidden in dust and to resolve fine structures in the gas. Astronomers are expected to use the observations to investigate how the stars and protostars influence the surrounding cloud. The release does not claim that the observations settle how such regions evolve; instead, it presents NGC 7129 as a place where those interactions can be examined in detail.
