One of the greatest strengths of NASA’s James Webb Space Telescope is its ability to give astronomers detailed views of areas where new stars are being born. The latest example, shown here in a new image from Webb’s Mid-Infrared Instrument (MIRI), is NGC 346, the largest and brightest star-forming region in the Small Magellanic Cloud.
The Small Magellanic Cloud (SMC) is a satellite galaxy of the Milky Way, visible to the naked eye in the southern constellation of Tucana. This small companion galaxy is more primitive than the Milky Way because it has fewer heavy elements, which are forged into stars through nuclear fusions and supernova explosions, compared to our own galaxy.
Since cosmic dust forms from heavy elements such as silicon and oxygen, scientists expected the SMC to be devoid of significant amounts of dust. However, the new MIRI image, as well as an earlier image of NGC 346 from Webb’s near-infrared camera released in January, show a lot of dust within this region.
In this representative color image, blue tendrils trace emission from a material that includes dusty silicates and sooty chemical molecules known as polycyclic aromatic hydrocarbons, or PAHs. More diffuse red emission shines from warm dust heated by the brighter, more massive stars at the heart of the region. An arc in the center left may be a reflection of light from the star near the center of the arc. (Similar, fainter arcs appear associated with stars at the bottom left and top right.) Finally, bright patches and filaments mark areas with abundant protostars. The research team searched for the reddest stars and found 1,001 point light sources, most of them young stars still embedded in their dust cocoons.
By combining Webb’s data in both the near-infrared and mid-infrared, astronomers can make a more complete census of the stars and protostars within this dynamic region. The results have implications for our understanding of galaxies that existed billions of years ago, during an era in the universe known as “cosmic noon,” when star formation was at its peak and concentrations of heavy elements They were minors, as seen in the SMC.The James Webb Space Telescope is the world’s premier space science observatory.
Webb is solving mysteries in our solar system, looking beyond it to distant worlds around other stars, and exploring 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 the Canadian Space Agency.