{"id":33328,"date":"2024-03-04T15:25:31","date_gmt":"2024-03-04T04:25:31","guid":{"rendered":"https:\/\/astro3d.org.au\/?p=33328"},"modified":"2024-03-04T15:29:10","modified_gmt":"2024-03-04T04:29:10","slug":"astronomers-use-chemistry-to-understand-the-orbit-of-binary-stars","status":"publish","type":"post","link":"https:\/\/astro3d.org.au\/astronomers-use-chemistry-to-understand-the-orbit-of-binary-stars\/","title":{"rendered":"Astronomers use chemistry to understand the orbit of binary stars"},"content":{"rendered":"

When stars like our Sun end their lives, they throw off their outer layers through a dramatic stellar wind.<\/h1>\n

This stellar wind is a key source of dust in the universe and enriches the interstellar medium of the Galaxy with heavy elements that are produced during the star\u2019s death throes.<\/p>\n

W Aquilae (W Aql) is one star going through this process. Unlike our future Sun, however, W Aql is not dying alone, with a longer-lived sunlike star keeping it company as they orbit around each other. Before work led by ASTRO 3D Associate Investigator Ta\u00efssa Danilovich, little was known about the orbit of the two stars, except that it was probably centuries long. Now, thanks to evidence of the two stars passing very close to each other \u2014 a process that left behind a chemical imprint \u2014 researchers can determine that the orbit has a very elliptical shape, as well as taking around a millennium to complete one cycle.<\/p>\n

A variety of molecules and dust make up the stellar wind of the dying star, and the researchers found that some of these were, unexpectedly, found only on one side of the system. Such an arrangement could only have happened with the aid of another hotter star.<\/p>\n

\u201cOnce we saw the silicon nitride emission off to one side, we knew something unusual was going on,\u201d says lead author Dr Ta\u00efssa Danilovich.<\/p>\n

The research team ran hydrodynamical simulations to understand how the sunlike star was shaping the stellar wind of the dying star. These showed that if the W Aql system was viewed side on, then something like concentric rings would form in the wind. These are visible in data taken with the ALMA telescope in Chile, and combined with observations from the SPHERE instrument on the Very Large Telescope and older observations from the Hubble Space Telescope, the team was able to understand the orbit well.<\/p>\n

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