Re: Flaring geosats soon for far north

From: Ed Cannon (ecannon@mail.utexas.edu)
Date: Wed Mar 10 2004 - 04:33:57 EST

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    I'm sorry to hear that the weather for Bram and others was
    so unfavorable.  Ours hasn't been too good here this winter,
    but we just had a very nice Tuesday evening (local time).
    I was able to see several flaring geosats with my handheld
    8x42 binoculars, and with Mike's 8-inch (20 cm) telescope,
    we saw at least eleven more.  And we stopped at about 11:00
    PM local time.  The action was roughly in the vicinity of
    RA 10:50-11:00, Dec -5.0, where they were nearing their
    entry into the Earth's shadow.  I didn't try to see the few
    farther west that also flare at the "wrong time", about 
    three hours early.
    
    One aspect of this phenomenon that's a bit tricky is that
    the conditions are most favorable when the observer is 
    close to the Earth's limb, as seen from the vantage point
    of the satellite.  That's either early in the evening or 
    late in the morning from here, when the satellites low in
    east (or west in the morning, though I've never tried to
    see those yet) are nearing eclipse.  I guess it's pretty 
    much all night long from high latitudes.  
    
    The photo that John Locker recently pointed out helps to 
    visualize this aspect of it:
    
    http://www.satobs.org/seesat/Mar-2004/0057.html
    
    An observer near the limb of the Earth is as close as 
    possible to the "perfect" alignment of Sun, satellite, 
    and observer.  Someone on the equator at midnight on the 
    equinox is at the least favorable position.
    
    Ed Cannon - ecannon@mail.utexas.edu - Austin, Texas, USA
    
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