The mystery of the Swirl<\/strong><\/h2>In images taken in both X-ray and visible light, there is a set of nested and overlapping rings.<\/p>
Named \u2018The Swirl\u2019 by its discoverer Frank Winkler (making it the object in the sky which most sounds like something a Star Trek<\/em> captain would encounter), it was originally thought to be the signature of a second supernova taking place within the remnant of the first.\u00a0<\/p>But there is a science paper that takes a close look at the Swirl and comes to a different conclusion.<\/p>
The authors argue that the Puppis A supernova remnant remnant is actually being sculpted by the presence of a second star, a companion to the supernova<\/a> progenitor, whose influence on the initial explosion is being revealed all these millennia later.\u00a0<\/p>The tool of choice is an integral field spectrograph, mounted on the 2.3-metre telescope at Siding Spring Observatory in Warrumbungle National Park, New South Wales, Australia.<\/p>
These instruments, which are slowly revolutionising professional astronomy, give not only an image of the target, but also a spectrum for each pixel within a grid.<\/p>
This gives the team two for the price of one \u2013 they can study the image to get a sense of the structure of the Swirl, while the spectra tell us how its movements and composition change across the object.<\/p>![\"Rings](\"https:\/\/c02.purpledshub.com\/uploads\/sites\/48\/2023\/12\/puppis-a-supernova-remnant-rings.jpg\")
Rings inside Puppis A suggest a massive as-yet-untraced star is sculpting the supernova remnant. Click on the image to zoom in. Credit: NASA\/GSFC\/S.Snowden et al\/NOAO\/AURA\/NSF\/Middlebury College\/F.Winkler et al<\/figcaption><\/figure>Arguments for a hidden star<\/strong><\/h2>With data in hand, they consider whether the Swirl could be material spewed into space by a wind from the progenitor before it went supernova.<\/p>
If this hypothesis is true, we\u2019d expect the Swirl\u2019s rings to be uniform, with no changes in composition from place to place.<\/p>
Instead, different rings are made of different things: the outermost one is nitrogen-rich, while inner components show oxygen and sulphur too.\u00a0<\/p>
As massive stars reach the end of their lives, they end up with an onion-like interior, their \u2018burning\u2019 of nuclear fuel producing layers of different heavy elements.<\/p>
The pattern seen in the Swirl corresponds to being made up of a series of these layers \u2013 though the pattern does break down slightly in the innermost components.\u00a0<\/p>
But why do we see a series of rings? This is where the presence of a companion comes in.<\/p>
If such a star exists, it would have got in the way of material flowing outwards during the supernova, producing a funnel shape, which we see as the Swirl.\u00a0<\/p>
It\u2019s an elegant explanation, but could the companion star have survived?<\/p>
Recent searches using data from the European Space Agency\u2019s Gaia satellite<\/a> have found nothing, though the authors suggest a broader search might be needed.<\/p>As ever, understanding the complexity of these fascinating objects requires more observations.\u00a0<\/p>
But there is a science paper that takes a close look at the Swirl and comes to a different conclusion.<\/p>
The authors argue that the Puppis A supernova remnant remnant is actually being sculpted by the presence of a second star, a companion to the supernova<\/a> progenitor, whose influence on the initial explosion is being revealed all these millennia later.\u00a0<\/p> The tool of choice is an integral field spectrograph, mounted on the 2.3-metre telescope at Siding Spring Observatory in Warrumbungle National Park, New South Wales, Australia.<\/p> These instruments, which are slowly revolutionising professional astronomy, give not only an image of the target, but also a spectrum for each pixel within a grid.<\/p> This gives the team two for the price of one \u2013 they can study the image to get a sense of the structure of the Swirl, while the spectra tell us how its movements and composition change across the object.<\/p> With data in hand, they consider whether the Swirl could be material spewed into space by a wind from the progenitor before it went supernova.<\/p> If this hypothesis is true, we\u2019d expect the Swirl\u2019s rings to be uniform, with no changes in composition from place to place.<\/p> Instead, different rings are made of different things: the outermost one is nitrogen-rich, while inner components show oxygen and sulphur too.\u00a0<\/p> As massive stars reach the end of their lives, they end up with an onion-like interior, their \u2018burning\u2019 of nuclear fuel producing layers of different heavy elements.<\/p> The pattern seen in the Swirl corresponds to being made up of a series of these layers \u2013 though the pattern does break down slightly in the innermost components.\u00a0<\/p> But why do we see a series of rings? This is where the presence of a companion comes in.<\/p> If such a star exists, it would have got in the way of material flowing outwards during the supernova, producing a funnel shape, which we see as the Swirl.\u00a0<\/p> It\u2019s an elegant explanation, but could the companion star have survived?<\/p> Recent searches using data from the European Space Agency\u2019s Gaia satellite<\/a> have found nothing, though the authors suggest a broader search might be needed.<\/p> As ever, understanding the complexity of these fascinating objects requires more observations.\u00a0<\/p>Arguments for a hidden star<\/strong><\/h2>