NASA’s James Webb Space Telescope has captured the infrared light of numerous features that previously were impossible to see beyond the thick dust of the FS Tau star system. In addition to myriad background galaxies that burst into view like fireworks for the United States’ 250th anniversary celebrations, this image flickers with a number of protostars, or baby stars that are formed from dense pockets of gas and dust. These hot, clumpy, and low-mass objects eventually will become full-fledged stars capable of burning hydrogen in their cores, like our Sun. The protostars of FS Tau are about 1 to 3 million years old, which is relatively young in cosmic scales. Our Sun, by contrast, is 4.6 billion years old.
Low-mass stars emit less radiation and have less energetic stellar winds than those with larger masses, which means they disrupt their environment at a much lower level. This makes the FS Tau region incredibly useful for studying low-mass star evolution without the same level of environmental interference seen near higher-mass stars. A pair of protostars that creates the largest diffraction pattern seen slightly to the left of center in the image, called FS Tau A, is about half the mass of our Sun.
In infrared light, NASA’s James Webb Space Telescope reveals bright protostars in star system FS Tau and a tapestry of background galaxies. FS Tau B, the orange protostar slightly right of center, is thought to be responsible for the orange outflows amid the dusty region.
Image: NASA, ESA, CSA, STScI; Image Processing: Alyssa Pagan (STScI)
Even though these objects are young and low-mass, they still can impact their surroundings, partially due to the outflows they emit. These outflows, seen as orange and red wisps and wide sheets, are theorized to come from FS Tau B, the protostar slightly to the right of center that has an orange diffraction pattern. As FS Tau B feeds on the surrounding dust and gas to grow, it ejects some of that matter outward. The wider outflows are thought to come from the interaction between the protostar’s magnetic field and superheated matter closest to the protostar within its accretion disk. The disk is seen as a dark band that cuts across at a 30-degree angle.
The gaps between the outflows, newly discovered in this Webb observation, add to growing evidence that protostars accrete matter in discrete episodes. In the periods where protostars gather material and increase in mass, they also eject superheated matter in different directions. In between these episodes, they are relatively quiet.
A comparison between the observations of FS Tau by NASA’s Hubble and James Webb space telescopes. Hubble’s visible-light view shows the star-forming region mostly obscured by thick dust. Webb sees through the dust, revealing how the protostars are shaping their surroundings.
Image: NASA, ESA, CSA, STScI; Image Processing: Alyssa Pagan (STScI)
As protostars eject these outflows, they shape their surroundings. This is best shown by the prominent light-blue ridges of dust and gas near FS Tau B. These thicker regions were likely created as outflows struck and compressed matter together. The brightness of these light-blue ridges shows that the nearby protostar’s light is reflected. Moreover, Webb’s sensitivity reveals the varying textures of dust and gas across the entire region.
The range of colors seen in this observation also provides a wealth of information, specifically about where dust is and how much of it obscures the region. Light with bluer wavelengths is absorbed and scattered by dust, while redder-wavelength light is able to slip through. Therefore, background galaxies behind thicker foreground dust appear redder. Alternatively, yellow galaxies have much less dust obscuring them. The few white stars visible in this image are likely in the foreground.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
To learn more about Webb, visit:
The following sections contain links to download this article’s images and videos in all available resolutions followed by related information links, media contacts, and if available, research paper and Spanish translation links.
English (UK) 
English (United States)