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I was once with a group at a small local observatory, trying to take a look at Venus, low over the horizon. As the rotating roof rolled into the correct positio
by exitb 2y ago
I was once with a group at a small local observatory, trying to take a look at Venus, low over the horizon. As the rotating roof rolled into the correct position, it turned out that a Yagi-style antenna mounted outside sat right in middle of the view. It seemed like something that'd ruin your day (or night), but it turned out that it really made no noticeable difference.
- ajb 2y agoI guess it's just down to the percentage of the aperture that is blocked? There's an amusing picture where a large owl has blocked a substantial portion of the view: https://apod.nasa.gov/apod/ap030401.html https://apod.nasa.gov/apod/ap030401.html
- exitb 2y agoYes. Given enough distance, the obstructing object will start to come into focus, but if it's close, it just darkens the image. After all reflecting telescopes have a secondary mirror (along with its mount) permanently obstructing part of the primary mirror.
- DoctorOetker 2y agoThis was not a telescope, it was an all sky camera, the caption explicitly states the owl scratched the optics with its claws.
- magicalhippo 2y agoGuess if you were imaging a bright star you'd might get some interesting diffraction spikes[1] though. [1]: https://en.wikipedia.org/wiki/Diffraction_spike https://en.wikipedia.org/wiki/Diffraction_spike
- madaxe_again 2y agoYou have to block a significant chunk of aperture to get them. This is useful, however, for focussing using a bahtinov mask. https://en.m.wikipedia.org/wiki/Bahtinov_mask https://en.m.wikipedia.org/wiki/Bahtinov_mask