The James Webb Space Telescope (JWST) from NASA has presented a new view of the nebula NGC 2392, known as the Lion Nebula, which draws attention due to its structure resembling a lion's muzzle.
The new image was obtained using the NIRCam instrument, which captures light in the near-infrared range, and MIRI, which specializes in the mid-infrared range. The combination of these instruments allows for clearer observation of ionized gas and dust structures compared to previous observations.
The Lion Nebula was previously captured by the Hubble Space Telescope in 2000 in visible wavelengths. However, Webb's infrared view reveals a more detailed structure of the nebula and allows for the study of various components of its formation.
At the center is a stellar remnant that gave rise to the nebula. Although it appears as a tiny dot in the middle of the lion's 'face', it is an extremely hot white dwarf whose radiation continues to alter the surrounding material.
This radiation also destroys the dust encountered in its path. Simultaneously, some filaments are able to withstand the intense stellar radiation.
NASA explains that the gas bubble continues to expand and transform the nebula. Understanding why this gas has such a complex structure with rings and shells remains one of the mysteries for astronomers.
Nebula Structure Details
One of the most noticeable features of the image is the structure resembling an animal's mane. According to NASA, this area corresponds to the inner part of the dust shell illuminated by the central white dwarf.
Small clumps, resembling tufts of fur or comet tails, are actually dense concentrations of dust. These clumps have managed to resist the radiation emanating from the stellar core and serve as a protective barrier for the material located behind them.
Webb is able to highlight these structures through its observations in the infrared range. Although the overall appearance of the nebula is similar to what Hubble recorded, the new observations demonstrate dense dust clumps and haze of ionized gas.
Thus, the image captures not just an interesting formation, but various stages of interaction between the radiation of a dying star and the material it itself ejected into space.
The structure of the Lion Nebula formed thousands of years ago, and this process is still ongoing. NASA describes Webb's images as a kind of frozen record of a transformation that does not cease.
NASA explains: 'Webb's images 'freeze' this planetary nebula in time, even though the death of the star and its dramatic consequences continue.'
However, this process will not be eternal. The gas and dust will continue to move away from the stellar core, and the nebula will eventually dissipate. Astronomers suggest that the Lion Nebula will disappear in about ten thousand years, which is a very short period compared to astronomical timescales.
Planetary nebulae, such as NGC 2392, are also important because they help astronomers understand the fate of Sun-like stars. Much more massive stars end their lives in supernova explosions, but these events occur relatively rarely. Most stars in the universe have smaller masses and undergo a different process at the end of their existence.
Instead of exploding, these stars release their outer layers, which turn into structures of gas and dust. The remaining core becomes an extremely hot white dwarf. In the case of the Lion Nebula, it is this white dwarf that continues to shape the nebula.
Thus, the central star not only left behind the structure we see in the image; it continues to shape and simultaneously destroy it. New Webb observations allow tracking this process with a level of detail unavailable in previous images.
The result is a portrait of a star in its final evolutionary stages and simultaneously a nebula that is slowly disappearing. The Lion Nebula still appears to be roaring in the Webb image, but from an astronomical perspective, its roar has an expiration date.
