Saturday, September 2, 2017

ASTRONOMERS PRODUCE BEST IMAGE OF A STAR TO DATE

 Astronomers using the European Southern Observatory's Very Large Telescope Interferometer (VLTI) have mapped the surface of the star Antares in unprecedented detail, creating the best image of a star's surface to date (excluding images of our own Sun).
 Through the VLTI's AMBER instrument, the astronomers were able to take the photo using near-infrared light, producing a resolution seven times smaller than the star's angular diameter and almost 12 times smaller than its full atmospheric extension. As an added bonus, the team was able to measure the speed of gas moving across the surface of Antares, a feat that has only ever been accomplished with our Sun up until now.
 The results also showed that Antares' atmosphere contains several clumps of gas that extend nearly two times the star's radius. Convection (the rising of heated gas and the sinking of cooled gas) does not explain this extension to such a great distance meaning some unexplained process must be at work in the star's atmosphere.
 Antares is a red supergiant star located about 550 light-years away with a mass of about 12 times as big as our Sun. It is the brightest star in the constellation Scorpius.
Read more about this fascinating story at: http://www.astronomy.com/news/2017/08/astronomers-map-antares
Image Credit: ESO/K. Ohnaka

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