Each winter we make a trip to L’Observatoire de Haute-Provence (or, OHP). I wrote about it before On this blog. It is always a challenge to find something new to photograph!
This year I spent a lot of time photographing heavy machinery inside the domes. Very old heavy machinery because this stuff was made in the 1950s. Here are the ventilation fans inside the dome of the largest telescope, the 193cm (this is the first telescope in the world that detected a planet around another star). Much later, other instruments like the Canada-France-Hawaii Telescope would also adopt similar strategies to improve atmospheric conditions inside the domes. The fans are an attempt to make air flow freely over the telescope and remove turbulence, which is the effect which make stars twinkle. Great for poets, not so great for astronomers.
At OHP, as far as I can tell, they are not used any more, and it’s not clear if they made a big difference. The “intrinsic seeing” of site is quite bad.