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    Occultation puzzle
    From: Peter Hakel
    Date: 2011 May 21, 00:07 -0700
    The Wikipedia entry for Aldebaran contains the following image:

    http://en.wikipedia.org/wiki/File:Occultation.jpg

    Based on the information on this page and after some trial and error with Excel (see attached) I came up with the following plausible coordinates in time and space at which this image may have been created:

    New Orleans area: 30N 90W
    UT: July 29, 1997,    10h 08m 30s

    This really should be only a point along an entire LOP of possible solutions, which I did not investigate further.  I neglected refraction which I'd think would have a small effect for such a tiny lunar distance (center-to-center topocentric LD = Moon SD = 15.5') and the overall achievable accuracy in this exercise (no obviously visible refractional flattening of Moon's disk).  Parallax is important (center-to-center geocentric LD = 34.4')

    Accompanying data look consistent with everything else:
    The Moon age (25 days, "waning crescent") and phase (23% or about 1/4 illuminated)
    Local time (UT-6h) => around 4am, about an hour before sunrise ("predawn")

    The two bodies would have appeared due east at an altitude of roughly 34 degrees.


    Peter Hakel

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