Astrology

James Webb images show the Lion Nebula's dying star shedding its outer layers

NASA's James Webb Space Telescope has captured new images of the Lion Nebula, formally known as NGC 2392, showing the structure left behind by a dying star now in its white dwarf phase, NASA reports via Kottke. The pictures, taken with the telescope's NIRCam and MIRI instruments, show a stellar core casting off its outer gas layers as the star nears the end of its life.

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A bubble of ionized hydrogen gas forms the lion's face#

NASA describes the nebula's glowing core as producing a bubble of ionized hydrogen gas that forms what looks like the face of a lion, with expanding shells and rings clearing away dust as they move outward, according to the agency's account via Kottke. The feature astronomers call the lion's mane is lit from within, offering a view toward the star's core, NASA reports.

A nebula is a part of the interstellar medium made of ionized, neutral or molecular hydrogen along with cosmic dust, and many nebulae mark regions where stars are born rather than where they die, according to Wikipedia. The Lion Nebula instead shows the opposite end of a star's life, as its outer layers disperse into space, NASA reports via Kottke.

Webb has turned up other unexplained signals elsewhere in the sky. Live Science reports the telescope identified a potential candidate for being among the most distant supernovas yet observed, a blast named AT 2026abck dated to around 1.15 billion years after the Big Bang, with light released more than 12.5 billion years ago. Separately, cristinaiglesias.com reports Webb detected a bright, unexplained infrared emission line near a wavelength of about 1.6 micrometres in the Hubble Ultra Deep Field, a patch of sky where no galaxy or star had previously been recorded, with the signal registering twice over roughly 88 days.

The structure will fully disperse in about 10,000 years#

Though the nebula appears unchanging on human timescales, NASA says its gas and dust took shape over several thousand years and the whole structure is expected to disperse completely in roughly 10,000 years, a brief span in astronomical terms, according to the agency's account via Kottke.

Webb has also been turned toward objects closer to home. Dagens.com reports the telescope found that two narrow rings circling the asteroid Chariklo, a 250-kilometer-wide body orbiting between Saturn and Uranus on a 62-year orbit, are actively shifting in thickness and density, a discovery planetary scientist Vincent Kofman of the University of Oslo called surprising given assumptions that the outer solar system is too cold for such activity.

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