
ALMA telescope reveals the Sun in new light - autocorr
https://public.nrao.edu/news/pressreleases/2017-alma-solar-campaign
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autocorr
This is a better writeup [1] but only includes one of the figures. For some
context, the ALMA observatory is a radio telescope array that works at
wavelengths of around a millimeter. The images show the intensity of the radio
emission and are only in a false-color black-orange color scheme. These are
the best images ever taken of the Sun at these wavelengths, you can see that
the first two "zoom in images" are essentially focused just on that black pip
centered in the third figure.

One thing that makes ALMA unique for these kind of observations is that it can
actually observe the Sun--without melting the secondary mirrors from the
focused sunlight that is. The antennas are designed to be reflective in the
radio, but diffusely scatter optical and infrared light in all directions. The
Swedish SEST observatory was not so lucky, and after accidentally pointing at
the Sun it's secondary mirror burst into flames (see footnote 2 in [1], here
are some pictures [2]).

[1]
[https://www.eurekalert.org/pub_releases/2017-01/e-aso011717....](https://www.eurekalert.org/pub_releases/2017-01/e-aso011717.php)

[2]
[https://www.eso.org/public/images/?search=%2Bsest+%2Bfire](https://www.eso.org/public/images/?search=%2Bsest+%2Bfire)
(see footnote two in above)

