Unk 90907 observed (I think.)

From: Ed Cannon (ecannon@mail.utexas.edu)
Date: Wed Aug 28 2002 - 04:39:20 EDT

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    Last night I looked for and believe I found unknown 90907, a 
    probable payload which is in close to a 12-hour orbit.  Its 
    flash period is about 5 seconds, with variable maxima, a few
    of which were as bright as +6.0 I estimate.  I was searching 
    with my 10x50 binoculars, handheld.  Using Highfly predictions 
    from the following Int2-propagated elements, the object seemed 
    to be running about 5.5 minutes early:
    
    1 90907U          02237.25412428 -.00000723  00000-0  00000+0 0    02
    2 90907  63.0902 153.5499 6897454 283.4713    .0000  2.01488208    07
    
    I apologize for the following very rough and improperly 
    formatted positional estimates (UTC time; 2000 RA & Dec):
    
    2002/08/28 04:25:29  22:22, +2.1
    2002/08/28 04:29:04  22:28, -0.8 (shadow entry soon after?)
    
    Observing site, E. Ney Museum grounds, 30.307N, 97.727W, 150m.
    The waning gibbous Moon was very low in the sky and behind a
    building at the time.  The weather conditions were pretty good.
    
    I don't know how to adjust elements based on observations.
    
    To my knowledge, this object may not have been observed in 
    about 15 months.  Here are the elements I somehow happened to 
    use as input for the Int2 run:
    
    Unknown 990907   4.0  2.0  0.0  6.0 v    8
    1 90907U 99550A   01143.56958075-0.00001312  00000-0 -84578+0 0    00
    2 90907  62.9886 206.7942 7004970 284.4760   0.0000  2.01441359    03
    
    These, with no drag, are from the mccants.tle file of August 27:
    
    Unknown 990907   4.0  2.0  0.0  6.0 v    8
    1 90907U 99550A   01143.56958075 0.00000000  00000-0 +00000+0 0    09
    2 90907  62.9886 206.7942 7004970 284.4760   0.0000  2.01441359    03
    
    Now, there is definitely a significant element of uncertainty 
    here until more -- and *much* better! -- observations are made, 
    but I did check for any known flashing Centaurs and the like 
    and did not get any other match using the mccants.tle and 
    eccen.tle files.
    
    Here's an Int2-generated element set for day 240, using the set
    above that has non-zero drag:
    
    1 90907U          02240.23200059 -.00000893  00000-0  00000+0 0    07
    2 90907  63.0876 153.2103 6897688 283.4622    .0000  2.01483383    03
    
    Muses B M-5 Rk (97-005B, 24721) is making near-perigee, very
    fast passes over here every third night.  Last night it had 
    asymmetrical secondary maxima; PPAS report:
    
    97-  5 B 02-08-28 02:03:46   EC   40.5 0.4   7  5.8   +4.5->inv asymm 2ndary
    
    (Brightest maxima may have been +3.5 -- just not sure.)
    
    I didn't find Gorizont 23; ended session about midnight; it's
    pretty low in the sky now, and I was in town (worse city glow
    low in the SW than BCRC site). 
    
    Ed Cannon - ecannon@mail.utexas.edu - Austin, Texas, USA
    
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