Quote:
Originally Posted by Caglow
If it is 2 feet wide (and if my 20" diameter guess is about right), then the bird would be flying at ~26,426 feet high.
If 1 feet wide, then ~10,313 feet high.
if 3 inches wide, then ~2,578 feet high.
My guess would be some kind of insect in front of the sun...likely a gnat.
Formula:
distance = (size/2) * 1/tan(apparent size/2)
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I decided on a bird rather than a bug because it would have to be a very large bug, far away, since the telescope would probably not be in focus closer than a few dozen meters. A telescope with the full sun in its view would be out of focus on a nearby gnat.
It would help to know the focal length of the telescope and its f stop.
We can’t tell the size of the thing. It could be a small bird 100 to 200 meters away.
Also, figure how far away a bird or bug would have to be so that it would take that amount of time to cross the image of the sun, from our viewing position on the surface of the earth.