ESO: Best Ever Image of a Star’s Surface and Atmosphere

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bystander
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ESO: Best Ever Image of a Star’s Surface and Atmosphere

Post by bystander » Wed Aug 23, 2017 3:28 pm

Best Ever Image of a Star’s Surface and Atmosphere
ESO Science Release | VLTI | 2017 Aug 23

First map of motion of material on a star other than the Sun
[img3="Credit; ESO/K. Ohnaka"]https://cdn.eso.org/images/screen/eso1726a.jpg[/img3][hr][/hr]
Using ESO’s Very Large Telescope Interferometer astronomers have constructed the most detailed image ever of a star — the red supergiant star Antares. They have also made the first map of the velocities of material in the atmosphere of a star other than the Sun, revealing unexpected turbulence in Antares’s huge extended atmosphere. The results were published in the journal Nature.

To the unaided eye the famous, bright star Antares shines with a strong red tint in the heart of the constellation of Scorpius (The Scorpion). It is a huge and comparatively cool red supergiant star in the late stages of its life, on the way to becoming a supernova [1].

A team of astronomers, led by Keiichi Ohnaka, of the Universidad Católica del Norte in Chile, has now used ESO’s Very Large Telescope Interferometer (VLTI) at the Paranal Observatory in Chile to map Antares’s surface and to measure the motions of the surface material. This is the best image of the surface and atmosphere of any star other than the Sun. ...

Using the new results the team has created the first two-dimensional velocity map of the atmosphere of a star other than the Sun. They did this using the VLTI with three of the Auxiliary Telescopes and an instrument called AMBER to make separate images of the surface of Antares over a small range of infrared wavelengths. The team then used these data to calculate the difference between the speed of the atmospheric gas at different positions on the star and the average speed over the entire star [2]. This resulted in a map of the relative speed of the atmospheric gas across the entire disc of Antares — the first ever created for a star other than the Sun.. ...

Vigorous Atmospheric Motion in the Red Supergiant Star Antares - K. Ohnaka, G. Weigelt, K.-H. Hofmann
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Re: ESO: Best Ever Image of a Star’s Surface and Atmosphere

Post by neufer » Wed Aug 23, 2017 3:58 pm

https://en.wikipedia.org/wiki/Antares wrote:
<<Antares (radius ~ 883 R), like the similarly-sized red giant Betelgeuse (radius ~ 887 R), will almost certainly explode as a supernova, probably within the next few hundred thousand years. For a few months, the Antares supernova could be as bright as the full moon and be visible in daytime.>>
"Ford's copy of The Hitchhiker's Guide to the Galaxy smashed into another section of the control console with the combined result that the guide started to explain to anyone who cared to listen about the best ways of smuggling Antarean parakeet glands out of Antares (an Antarean parakeet gland stuck on a small stick is a revolting but much sought after cocktail delicacy and very large sums of money are often paid for them by very rich idiots who want to impress other very rich idiots), and the ship suddenly dropped out of the sky like a stone."
Art Neuendorffer

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