The captivating image captured by NASA/ESA/CSA's James Webb Space Telescope unveils the intricate beauty of N79, an H II region nestled in the Large Magellanic Cloud (LMC), one of our Milky Way's satellite galaxies. This nebula, known as N79, is a vast expanse of interstellar atomic hydrogen, brought to life by Webb's Mid-InfraRed Instrument (MIRI), which unveils the ionization of this cosmic marvel.
N79 stretches across approximately 1,630 light-years in the relatively unexplored southwest region of the LMC, making it a colossal star-forming complex. Often regarded as a younger counterpart to the famous 30 Doradus, or the Tarantula Nebula, N79 has been a recent focus of Webb's attention. Researchers have uncovered that N79 exhibits a star formation efficiency surpassing that of 30 Doradus by a factor of two over the past half a million years.
This mesmerizing image zeroes in on one of the giant molecular cloud complexes within N79, named N79 South (S1). The prominent “starburst” pattern surrounding this luminous object is a result of diffraction spikes. These spikes, a common artifact in telescopes with mirrors, emerge due to the hexagonal symmetry of Webb's 18 primary mirror segments. They become noticeable around intensely bright, compact objects where light emanates from a single source. The unique patterns do not manifest in most galaxies since they are generally darker and more spread out than a solitary star.
Webb's MIRI captures longer wavelengths of light, providing a view of N79 that emphasizes the glowing gas and dust within the region. Mid-infrared light proves valuable as it penetrates deeper into the clouds, revealing the inner workings that shorter wavelengths might be absorbed or scattered by dust grains in the nebula. Notably, this field showcases some protostars still embedded within.
Astronomers are particularly drawn to star-forming regions like N79 due to their similar chemical composition to the massive star-forming regions observed during the universe's early stages when star formation was at its zenith. In contrast, star-forming regions within our Milky Way are not generating stars at the same prolific rate as N79, boasting a different chemical makeup. Webb's observations of N79 offer astronomers a unique opportunity to juxtapose star formation in this region with the telescope's deep insights into distant galaxies from the early universe.
These observations are part of Webb's broader program, delving into the evolution of circumstellar disks and envelopes around forming stars across various masses and evolutionary stages. Webb's remarkable sensitivity opens a new frontier, enabling scientists to detect, for the first time, planet-forming dust disks around stars akin to our sun's mass at the distance of the LMC.
The image's color coding adds another layer of richness to the narrative, with 7.7-micron light depicted in blue, 10 microns in cyan, 15 microns in yellow, and 21 microns in red. These filters (770W, 1000W, 1500W, and 2100W) contribute to a holistic understanding of the nebula's composition and dynamics.
Source: European Space Agency