Wherever JWST looks in space, matter and energy interact in spectacular images. Webb reveals more detail in these interactions than any other telescope because it can see through the dense gas and dust that masks many objects. In the new image, JWST sees a young protostar that is only about 100,000 years old.

The star is called L1527, and despite its young age, it’s still inside the molecular cloud that gave birth to it. That’s one of the reasons NASA created JWST (with help from ESA and CSA). The telescope can see through dust and gas to reveal the earliest stages of star formation.

This image was taken with MIRI’s Mid-Infrared Instrument. A young protostar is at the center of everything, still growing. It is accumulating mass from the surrounding protoplanetary disk. The disk is the small dark horizontal line in the center of the image.

A protostar is not a main sequence star, so it does not undergo fusion like the Sun. It may have a small amount of deuterium fusion in its core, but it produces energy in a different way.

As the star’s gravity pulls the material closer, it is compressed and heated. More energy comes from shock waves created when the incoming material collides with the existing gas. This is the energy that illuminates the star and its surroundings in the giant molecular cloud that gave birth to it.

As young protostars accumulate mass, they create powerful magnetic fields. These fields, combined with the star’s rotation, push matter away from the star.

As the protostar gains mass, it blasts some of its mass back into space in spectacular hourglass-shaped jets that shoot out from the star’s poles. These jets create visible main shocks in the material around the star, filamentary structures.

The star’s surroundings contain polycyclic aromatic hydrocarbons (PAHs), organic compounds found throughout the universe that may have contributed to the emergence of life. They glow blue in the image, including filamentous structures.

The red region in the center is a thick layer of gas and dust surrounding the young star, illuminated by the star’s energy. The white area between red and blue is a mixture of material. There are more PAHs here, as well as ionized gases like neon and other hydrocarbons. This isn’t JWST’s first look at L1527. It first observed the star in 2022 with the Near Infrared Camera (NIRCam).

Over time, the protostar’s powerful outflows will clear most of the surrounding gas and dust, although it will still have a protoplanetary disk. Eventually, the star will become a main sequence star that is easy to see without the gas-dust curtain. By then, the star’s planetary system will have formed.

There are unanswered questions about protostar formation, and one of the main scientific goals of JWST is star formation. For example, astrophysicists do not know exactly how and when fusion begins and a protostar becomes a main sequence star.

Although astronomers know that strong magnetic fields surround protostars, they don’t know exactly how they form or what role they play in the collapse and rotation of the star. JWST has made some progress in this area. It was recently confirmed that jets from young stars are aligned due to the rotation and magnetic fields of the star; this is supported by theory but not yet confirmed by observation.

There are also uncertainties about how binary stars form. Do they form like individual stars? Why are there so many binary stars? The exact nature of the events that trigger star formation is also unknown. Shock waves from supernovas can trigger star birth, but what about other situations? Is it just a matter of density?

The answers to these questions will come step by step. JWST is making progress one image at a time, with the ability to see more detail in young stars and the swirling clouds of gas and dust surrounding them.