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    Re: Jupiter in daylight and micrometer test
    From: Frank Reed
    Date: 2016 Apr 20, 00:03 -0700

    Peter Monta, you wrote:
    "Would it help to suspend a collimated source in midair near the object of interest? "

    Interesting idea! I have never experimented with a collimated light source, but even an un-collimated marker, if far enough away to be nearly in focus helps tremendously. That's a mouthful to refer to a high tree branch or a roof peak. The catch is getting the angular alignment right. For example, if I know that Jupiter is at altitude 42° and azimuth 141°, I can probably find it in late afternoon in a clear sky if I can place a tree branch right next to that exact location. A workable trick is to find it in a telescope based on true coordinates. Jupiter is almost always visible in a typical backyard telescope, like my old 6" reflector, even in the middle of the day so long as the sky is a nice deep blue. Then switch to binoculars by sighting along the telescope tube. Once you find it binoculars, you can "walk" the planet to a convenient foreground object like a high tree branch. Now aligned with the branch, you lower your binoculars and run a very slow search pattern close to the foreground tree branch. I have found Jupiter in late daylight this way a few times. It sure is easier when the Moon is close by...

    Frank Reed

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