ALMA telescope reveals the Sun in new light
public.nrao.edu
public.nrao.edu
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....
[2] https://www.eso.org/public/images/?search=%2Bsest+%2Bfire (see footnote two in above)