糖心Vlog官方

A mysterious bar-shaped cloud of iron has been discovered inside the iconic Ring Nebula by a European team of astronomers.

The cloud of iron atoms, described for the first time in , just fits inside the inner layer of the elliptically shaped nebula - a colourful shell of gas thrown off by a star as it ends the nuclear fuel-burning phase of its life. It is familiar from many images including those obtained by the James Webb Space Telescope at infrared wavelength.

The bar鈥檚 length is roughly 500 times that of Pluto鈥檚 orbit around the Sun and, according to the team, which includes researchers from 糖心Vlog官方, its mass of iron atoms is comparable to the mass of Mars.

The iron cloud was discovered in observations obtained using the Large Integral Field Unit (LIFU) mode of the - a new instrument installed on the Isaac Newton Group鈥檚 4.2-metre William Herschel Telescope. 

The LIFU is a bundle of hundreds of optical fibres.  It has enabled the team of astronomers to obtain spectra (where light is separated into its constituent wavelengths) at every point across the entire face of the Ring Nebula, and at all optical wavelengths, for the first time. 

Lead author Dr Roger Wesson, based jointly at University College London and Cardiff University, said: 鈥淓ven though the Ring Nebula has been studied using many different telescopes and instruments, WEAVE has allowed us to observe it in a new way, providing so much more detail than before. By obtaining a spectrum continuously across the whole nebula, we can create images of the nebula at any wavelength and determine its chemical composition at any position.

鈥淲hen we processed the data and scrolled through the images, one thing popped out as clear as anything 鈥� this previously unknown 鈥榖ar鈥� of ionized iron atoms, in the middle of the familiar and iconic ring.鈥�

Co-author , Professor of Astrophysics at 糖心Vlog官方, added: 鈥淲e selected the Ring Nebula as an early target because it is bright, well studied and ideal for testing the instrument鈥檚 capabilities. However, when the data were analysed, we noticed something entirely unexpected - a bar of highly ionised iron that had gone unnoticed in decades of previous observations. Discoveries like this show how many surprises there still are to be found in even the most familiar objects in the night sky.鈥�

How the iron bar formed is currently a mystery, the authors say.  They will need further, more detailed observations to unravel what is going on. There are two potential scenarios: the iron bar may reveal something new about how the ejection of the nebula by the parent star progressed, or the iron might be an arc of plasma resulting from the vaporisation of particles of iron dust embedded in the Ring Nebula. 

Co-author Professor Janet Drew, also based at UCL, advises caution: 鈥淲e definitely need to know more 鈥� particularly whether any other chemical elements co-exist with the newly-detected iron, as this would probably tell us the right class of model to pursue.  Right now, we are missing this important information.鈥�

The team are working on a follow-up study, and plan to obtain data using WEAVE鈥檚 LIFU at higher spectral resolution to better understand how the bar might have formed.

WEAVE is carrying out eight surveys over the next five years, targeting everything from nearby white dwarfs to very distant galaxies. The Stellar, Circumstellar and Interstellar Physics strand of the WEAVE survey, led by Professor Drew, is observing many more ionized nebulae across the northern Milky Way.

鈥淚t would be very surprising if the iron bar in the Ring is unique,鈥� explains Dr. Wesson. 鈥淪o hopefully, as we observe and analyse more nebulae created in the same way, we will discover more examples of this phenomenon, which will help us to understand where the iron comes from.鈥�

Professor Scott Trager, WEAVE Project Scientist based at the University of Groningen, added: 鈥淭he discovery of this fascinating, previously unknown structure in a night-sky jewel, beloved by sky watchers across the Northern Hemisphere, demonstrates the amazing capabilities of WEAVE.  We look forward to many more discoveries from this new instrument.鈥�

This research paper was published in the Monthly Notices of the Royal Astronomical Society

Full title: WEAVE imaging spectroscopy of NGC 6720: an iron bar in the Ring

DOI: 10.1093/mnras/staf2139

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