Webb telescope captures huge star-forming complex

This NASA/ESA/CSA James Webb Space Telescope image shows an H II region in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. This nebula, known as N79, is a region of ionized interstellar atomic hydrogen, captured here by Webb’s Mid-InfraRed Instrument (MIRI).

N79 is a massive star-forming complex spanning approximately 1,630 light years in the generally unexplored southwest region of the LMC. N79 is generally considered to be a younger version of 30 Doradus (also known as the Tarantula Nebula), another of Webb’s recent targets. Research suggests that N79 has a star formation efficiency exceeding that of 30 Doradus by a factor of two over the past 500,000 years.

This particular image centers on one of three giant molecular cloud complexes, dubbed N79 South (S1 for short). The distinctive “star” pattern surrounding this bright object is a series of diffraction spikes. All telescopes that use a mirror to collect light, as Webb does, have this form of artifact that arises from the design of the telescope.

In Webb’s case, the six largest star spikes appear due to the hexagonal symmetry of the 18 segments of Webb’s primary mirror. Such patterns are only visible around compact, very bright objects, where all the light comes from the same place. Most galaxies, although they appear very small to our eyes, are dimmer and more extensive than a single star, and therefore do not exhibit this pattern.

At the longer wavelengths of light captured by MIRI, Webb’s view of N79 highlights the region’s glowing gas and dust. This is because mid-infrared light is able to reveal what’s going on deeper inside the clouds (whereas shorter wavelengths of light would be absorbed or scattered by dust grains in the nebula) . Some still-integrated protostars also appear in this field.

Star forming regions like this are of interest to astronomers because their chemical composition is similar to that of the gigantic star forming regions observed when the universe was only a few billion years old and star formation star was at its peak. The star-forming regions of our Milky Way galaxy do not produce stars at the same rapid rate as N79 and have a different chemical composition. Webb now offers astronomers the opportunity to compare and contrast observations of star formation in N79 with the telescope’s extensive observations of distant galaxies in the early universe.

These observations of N79 are part of a Webb program that studies the evolution of circumstellar disks and envelopes of forming stars over a wide mass range and at different stages of evolution. Webb’s sensitivity will allow scientists to detect planet-forming dust disks around stars of mass similar to our sun at the distance of the LMC for the first time.

This image includes 7.7 micron light displayed in blue, 10 micron in cyan, 15 micron in yellow, and 21 micron in red (770W, 1000W, 1500W, and 2100W filters, respectively).