〔놀라운 우주〕 심연에 휘날리는 ‘우주 사자’의 보랏빛 갈기

NASA's James Webb Space Telescope (JWST) recently released images of the planet-like nebula 'NGC 2392', estimated to be about 5,000 light-years away. Nebulas are clouds of gas and dust left behind by stars at the end of their life cycle, not directly related to planets as their name suggests. After exhausting their fuel, these stars either explode as supernovae or become white dwarfs, the latter being the case for most stars in the universe.

The white dwarf at the center of NGC 2392 is visible as a white dot in the center of the image. The gas and dust layers surrounding it give the nebula its striking resemblance to a lion's face and mane, earning it the nickname 'Lion Nebula'. It is estimated that the nebula itself is around 1 light-year in size, having taken thousands of years to reach its current form.

The ring-like structures forming the lion's face are formed by fast stellar winds (150,000 km per hour) from the central star, which heats and ionizes surrounding hydrogen gas, creating bubbles that overlap to form ridges and ridgy facial features. Unlike a balloon, this structure is not smooth but densely packed with high-density material in a fine, intricate mesh.

The outer ring of the nebula contains intricate structures resembling comets, with a dense dust clump protecting the gas and dust tail from the universe. Astronomers predict that the lion face will continue to grow until around 10,000 years from now, at which point it will fade away. The lion-like appearance of NGC 2392 was first identified by the Hubble Space Telescope in 2000 using visible light.

JWST, however, captured the nebula's inner dust clumps and gas filaments using its infrared cameras, revealing details that Hubble's visible light instruments could not see. NGC 2392 was first observed by British astronomer William Herschel in 1787, who famously discovered Uranus around the same time.