This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: The NASA/ESA/CSA James Webb Space Telescope recently imaged NGC 2392 (also known as the Lion Nebula), named for its distinctive appearance, which resembles a lion's face seen head-on. The venerable Hubble Space Telescope (HST) also viewed this nebula in 2000, showcasing its population of hazy, comet-shaped objects.
By combining data from its Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI), Webb has provided the clearest, most detailed view yet of the Lion Nebula. The image reveals the nebula's complex structure and the white dwarf at its center, which continues to shape it. This stellar remnant created the nebula when it reached the end of its life cycle and shed its outer layers.
This star looks like the lion's nose, while the extended gaseous envelope, shells of dust and tendrils resemble its "mane." The central star is so hot that it illuminates everything inside the bubble, ionizing hydrogen and causing it to expand and destroy much of the dust it encounters. While more massive stars collapse at the end of their lives and shed their outer layers in an explosive event (a supernova), lower-mass stars that produce nebulae such as NGC 2392 are different. When these stars exhaust their hydrogen and helium fuel, they become unstable and begin to pulsate, blowing off their outer layers in the process.
The powerful radiation from the stellar remnant drives the ejected material away, leaving behind a white dwarf surrounded by a shell of gas and dust. This is how most observable dust in the universe is produced. In the case of the Lion Nebula, the progenitor star was oxygen-rich, leaving behind a white dwarf that heats everything inside the bubble and ionizes the hydrogen gas.
The gas bubble is expanding, clearing most of the dust in its path and creating the complex structure of rings and shells visible in the image. Understanding these structures, common in planetary nebulae, remains an active area of astronomical research. While Webb's images appear similar to Hubble's optical images at first glance, Webb's infrared instruments highlight certain features.
These include compact clumps of dust that appear red, orange and yellow in the image, as well as haze caused by ionized gas. These clumps survived the expanding gas cloud and protect material beyond them. The powerful forces that cause the nebula to appear this way are ongoing and will continue to alter its shape as its gas and dust migrate away from the stellar core.
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