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    Vega over Chicago
    From: Frank Reed CT
    Date: 2006 Sep 27, 20:05 EDT

    Last night at 7:07:00 Central Daylight Time, I  was standing next to a street
    light here in Chicago. Looking up the pole, I  noticed Vega very close to he
    zenith. So I pulled out an index card ruled with  lines spaced 0.25 inches
    apart and measured the distance between Vega and the  zenith. I judged the
    position of the zenith by visually extending the sides of  the pole to the point
    where they met. I knew the distance to my hand at arm's  length looking up was 16
    inches so it was a simple matter to get the distance in  degrees. I found
    that Vega was 3.3 degrees south of the zenith and 0.8 degrees  west of the
    Almanac data: Vega's Dec: 38d 48'. Vega's GHA at  1900 CDT (0h GMT): 86d 21'.
    So at 1907 CDT, the GHA would be 88d 07'.
    I  can calculate my latitude right away. It's 38.8+3.3 or 42.1 North. Next I
    have  to convert the angle west of the zenith to Local Hour Angle. For small
    angles,  that's easy, I think. I divide the measured angle, 0.8 degrees, by the
    cosine of  my latitude. That gives 1.1 degrees. So my longitude must be
    88.1-1.1 or 87.0  West.
    My actual position at the time of this observation was 41d 56'  50"N, 87d 39'
    47"W so the error is about 0.15 degrees in latitude and 0.65  degrees in
    longitude. I'm fairly confident that I was able to estimate the  angles accurate
    to +/-0.2 degrees so I attribute the error in longitude to a  tilted lamp post.
    42.0N 87.7W, or 41.4N  72.1W.
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