James Webb Space Telescope Uncovers Unique Star-Forming Secrets of N79 in LMC

Astronomers using the James Webb Space Telescope have captured a stunning image of N79, a star-forming region in the Large Magellanic Cloud (LMC) that may serve as a younger version of the Tarantula Nebula. This observation provides valuable insights into the early Universe’s star formation processes and chemical compositions, which differ significantly from those in our Milky Way galaxy.

The James Webb Space Telescope (JWST or Webb) is an orbiting infrared observatory that complements and extends the discoveries of the Hubble Space Telescope. It covers longer wavelengths of light, allowing it to see inside dust clouds where stars and planetary systems are forming, as well as observe the first galaxies that formed in the early Universe. In a recent image taken by the Webb telescope, N79, a key star-forming region in the LMC, is showcased for its efficiency and chemical uniqueness compared to the Milky Way.

N79 is a massive star-forming complex spanning approximately 1630 light-years in the southwest region of the LMC. It is considered a younger version of 30 Doradus, also known as the Tarantula Nebula, another target of the Webb telescope. Research indicates that N79 has a star formation efficiency twice that of 30 Doradus in the past 500,000 years.

The image focuses on one of the three giant molecular cloud complexes within N79, known as N79 South (S1). The distinctive “starburst” pattern surrounding the bright object in the image is a result of diffraction spikes, which occur due to the telescope’s design. The Webb telescope has six largest starburst spikes that appear because of its hexagonal symmetry caused by the 18 primary mirror segments.

The image captured by the Webb telescope reveals the glowing gas and dust within N79. Mid-infrared light, detected by the Webb’s Mid-InfraRed Instrument (MIRI), offers a deeper view inside the cloud, as shorter wavelengths of light would be absorbed or scattered by dust grains. The image also shows some still-embedded protostars.

Star-forming regions like N79 are of great interest to astronomers because their chemical composition resembles that of gigantic star-forming regions observed billions of years ago when star formation was at its peak. Compared to our Milky Way, which produces stars at a different rate and has a different chemical composition, N79 provides an opportunity for astronomers to study the evolution of circumstellar discs and envelopes of forming stars. Webb’s sensitivity allows scientists to detect planet-forming dust discs around stars of similar mass to our Sun, even at the distance of the LMC.

The image of N79 captured by the Webb telescope includes different wavelengths of light, with 7.7-micron light shown in blue, 10 microns in cyan, 15 microns in yellow, and 21 microns in red. These observations form part of a program to study the evolution of forming stars’ circumstellar discs and envelopes at different evolutionary stages and mass ranges. Webb’s deep observations of distant galaxies in the early Universe provide a basis for comparing and contrasting star formation in N79.