A star in its death throes glows like gold in new images from the James Webb Space Telescope.
Messier 57, or the Ring Nebula, is a glowing ring of gas in the constellation Lyra, about 2,750 light-years from Earth, made of material ejected by a low-mass star as it dies. JWST's spectacular resolution will reveal intricate knots and patterns in this material to help better understand what happens when stars like the Sun reach the end of their lives.
Messier 57, or the Ring Nebula, is a glowing ring of gas in the constellation Lyra, about 2,750 light-years from Earth, made of material ejected by a low-mass star as it dies. JWST's spectacular resolution will reveal intricate knots and patterns in this material to help better understand what happens when stars like the Sun reach the end of their lives.
"We are witnessing the final chapters of a star's life, a preview of the Sun's distant future, and JWST's observations have opened a new window into understanding these awe-inspiring cosmic events," says Mike Barlow, astrophysicist at University College London in the UK and co-leader of the international JWST Ring Nebula Project.
"We can use the Ring Nebula as our laboratory to study how planetary nebulae form and evolve."
Planetary nebulae have nothing to do with planets; they were so named because 18th-century astronomers thought their round shape resembled a planet. In fact, they are much larger and much more dynamic: clouds of matter surrounding stars smaller than eight solar masses that have reached the end of their lives.
When their cores run out of material to fuse, these stars destabilise and eject all their outer material. No longer supported by the outward pressure of fusion, the stellar core collapses under gravity into a white dwarf. This is the ultimate fate of the Sun and most stars in the Milky Way.
From our point of view, the Ring Nebula was created by a star that reached the end of fusion within the last 2000 years. At its centre is a white dwarf about 60 per cent of the mass of the Sun; the material around this star is expanding out into space in a sphere that looks to us like a ring filled with glowing material.
The outer shell of the nebula is thick and dusty and carved into complex structures where it enters and interacts with the interstellar medium. Studying these structures can help scientists understand the physical processes involved in the planetary nebula's shape and expansion; and JWST provided breathtaking detail.
"The James Webb Space Telescope has provided us with an extraordinary image of the Ring Nebula that we have never seen before," says Barlow. "The high-resolution images not only showcase the intricate details of the nebula's expanding shell, but also reveal the inner region around the central white dwarf in perfect clarity."
The data are still in the analysis phase, but the observations are already revealing an unexpected complexity that the team is excited to investigate. In addition to the incredible detail seen in the structure of the shell, the observations have provided a wealth of data on the composition of the nebula, including large, carbon-based molecules whose origin is currently uncertain.
"These images have much more than aesthetic appeal; they offer a wealth of scientific information on the processes of stellar evolution," says astrophysicist Nick Cox of ACRI-ST in France and co-leader of the JWST Ring Nebula Project.
"By studying the Ring Nebula with JWST, we hope to gain a deeper understanding of the life cycles of stars and the elements they release into the cosmos."
Source: https://www.sciencealert.com/
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