Dying star analysed by Cardiff University scientists reveals new structures of its star system
Researchers at Cardiff University say new images of a dying star have revealed the structure of its star system that have never been seen before.
The star is at the centre of the Ring Nebula, which is said to be 2,600 light years away from Earth.
The Ring Nebula is a well-known planetary nebula. Planetary nebulae are the shells of gas and dust ejected from dying stars.
Planetary nebulae such as the Ring form when stars exhaust the hydrogen in their cores and eject their outer layers.
The new images "reveal structures that no previous telescope could detect," according to Dr Roger Wesson, a Research Associate at Cardiff University’s School of Physics and Astronomy.
As the source of much of the carbon and nitrogen in the universe, the way in which these stars evolve and die is crucial to understanding the origin of these elements, without which life on Earth could not have developed.
The team, led by researchers at Cardiff University’s School of Physics and Astronomy, say the images of the Ring Nebula captured by NASA's James Webb Space Telescope (JWST), show it to be part of a triple star system.
A triple star system is made up of three main stars which orbit the centre of mass.
The never-before-seen details were discovered by the telescope between July and August 2022. They've shown 20,000 dust clouds, known as globules, in the nebula which are rich in molecular hydrogen.
In this way, nebulae like the Ring Nebula reveal a kind of astronomical archaeology, as astronomers study the nebula to learn about the star that created it.
Dr Wesson said: “Planetary nebulae were once thought of as very simple objects, roughly spherical and with a single star at their centre.
"[The] Hubble [telescope] showed that they were much more complicated than that, and with these latest images JWST is revealing yet more intricate detail in these objects."
“The evidence that the star has a close binary companion shaping its outflow provides some long-sought answers about how this intricate detail arises.”
“We can now see the subtle influence of a third, previously unknown star in the system, alongside a much more distant companion which was identified in 2021. This third star has sculpted the outflow from the dying central star of the nebula and imprinted a faint concentric pattern into the outer parts of the nebula.”
The JWST international programme by NASA was launched in December 2021, along with its partners, the European Space Agency and the Canadian Space Agency.
The James Webb Space Telescope is NASA's largest and most powerful telescope and will be the main observatory for the next decade.
The hope is that it will enable astronomers across the world to study every phase in the history of our Universe.
Dr Mikako Matsuura, a Reader at Cardiff University’s School of Physics and Astronomy, said: “JWST’s six-metre diameter telescope is three times larger than Hubble’s and also operates two infrared cameras, which can detect longer wavelengths than are visible to the human eye or indeed Hubble.
“These telescope and infrared detection innovations mean many of the Ring’s details revealed in these latest JWST images were not previously visible to astronomers.
“Where before we saw only a ring, we now know it is filled with 20,000 globules. And, for the first time, we can also see beyond the ring which extends with faint spikes and arcs, shaping a petal-like structure resembling a flower.”
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