Had the opportunity to visit a most fascinating solar #observatory Thursday in #Switzerland near #Arosa, the Astrophysikalisches Observatorium #Tschuggen (AOT) which #MaxWaldmeier had built in 1939, which was abandoned in 1980 and which amateur astronomers are now bringing back to the state just at that time: Here are the original Kern #coronagraph and another one from #Zeiss (with a huge spectrograph) it's sitting on. See https://www.facebook.com/media/set/?vanity=dan.fischer.393&set=a.10230945670040155 for a picture album, with links to the background in the first comment.