RE: Decaying Raduga 33

From: Ted Molczan (molczan@rogers.com)
Date: Sun May 02 2004 - 04:44:01 EDT

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    Although Raduga 33 is in shadow during its passages through perigee, it may be
    sufficiently low to glow due to atmospheric heating.
    
    Coincidentally, its rocket body did just that, back in August of 1996, as
    observed by Stephen Bolton:
    
    http://satobs.org/seesat/Aug-1996/0151.html
    
    "The sat was at max brightness, approx -2, just prior to U. Maj. and before
    reaching max elevation above local horizon. Then appeared to slowly dim but
    remained visible with binoculars and glowing to loss near the NE horizon."
    
    Stephen was fortunate to observe the object about 30 s after its passage through
    perigee, about 97 km above the Earth.
    
    Raduga 33's perigee passages are somewhat higher, about 110 km, but that should
    be low enough for atmospheric heating to occur.
    
    As Mike McCants pointed out, the object's latitude of perigee is near 48 N;
    therefore, to observe atmospheric heating, observers must be near that latitude
    - the closer the better, but observers between about 43.3 N and 52.5 N are
    sufficiently close for perigee passage to occur at least 10 deg above their
    horizon. At those latitudes, passes will occur almost entirely in shadow, so the
    object will only be visible due to atmospheric heating.
    
    Anyone lucky enough to see it pass directly overhead while at perigee will see
    it move at a breathtaking 4.74 deg/s.
    
    Anyone who sees it (whether self-illuminated or sun-illuminated) should make an
    effort to make the "approximate positional observation" requested by Mike.
    Timing to the nearest second of closest approach to a known star, or passage
    between a pair of known stars should be sufficient. Try to note the position
    relative the star(s) at the moment of timing.
    
    Those of us with access to NASA/OIG should make certain to share updated elsets
    via SeeSat-L, as soon as possible after they are issued.
    
    Ted Molczan
    
    
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