3 ms·
They are "mask" which only allow some wavelengths so you can see different structure. https://en.wikipedia.org/wiki/Coronagraph https://en.wikipedia.org/wiki/C
by dekhn 4y ago
They are "mask" which only allow some wavelengths so you can see different structure.
https://en.wikipedia.org/wiki/Coronagraph https://en.wikipedia.org/wiki/Coronagraph