After a number of years of use, the mirror of the observatory’s 30 cm (12″) telescope was in need of a thorough cleansing. We used distilled water to soak the surface of the mirror and to get rid of insects, pollen and other dirt. More water was used for a final rinse. The central hole of the mirror shows signs of wear and oxidation, so we probably need to have it recoated in the near future. With a brush we wiped the inside of the tube clean, after which the original matt finish re-appeared.
Our annual visit to Europe’s largest astronomy fair; toys for boys. Less visitors than last year, and also a number of vendors that didn’t show up this year. I would have loved to see the new AstroTrack GEM. Nevertheless we had a very good time. We checked out different solar telescopes. Clear winners were the double-stacked scopes.