RE: STSS-ATRR 2nd stage elements from probable observation

From: Ted Molczan (ssl3molcz@rogers.com)
Date: Sat May 09 2009 - 16:34:07 UTC

  • Next message: Bram Dorreman: "Re: STSS-ATRR 2nd stage elements from probable observation"

    Bram Dorreman reports a chance sighting of an object he suspects to be the 2nd
    stage (09023B / 34904):
    
    http://satobs.org/seesat/May-2009/0082.html
    
    Bram reported two positions, both of which are in good agreement with the
    updated elements based on Marco Langbroek's apparently successful search for the
    object:
    
    1 71951U          09125.95957159  .01895775  00000-0  23000-2 0    02
    2 71951 112.7800 217.0376 0519924 282.5074  71.2250 15.08518086    07
    
    Marco and Bram observed the same pass, from locations not far apart. (Marco is
    in the Netherlands, Bram in Belgium.)
    
    Bram reported:
    
    > On Friday night May 8th I intended to start observing a "PPAS-object".
    > Before looking at the target area I saw a satellite moving in between
    > beta and gamma Ser, dividing the connection line in 1 and 2. Position
    > estimate RA 15:50 dec +15.7.
    
    The above elements place the object near that position at 21:02:03 UTC.
    
    > I followed this object because the inclination was more like Seasat
    > than like sun-synchronous satellites. It passed Edasich (iota Dra)
    > 1 minute 28 seconds later, estimate RA 15:25 dec +59.0.
    
    The above elements predict an appulse ~0.3 deg below iota Dra at 21:03:47, about
    1m44s after Bram's position. The time interval is not in good agreement with
    Bram's 1m28s, but the positions are close. Bram, is your 1m28s sufficiently
    precise that I should consider an attempt to improve the elements?
    
    These are nice examples of two of the common ways in which we make discoveries.
    Marco carried out a methodical search, based on the available information, using
    his experience to make allowances for uncertainties; Bram made a chance sighting
    of an object that followed a path that in his experience was unusual, so he
    followed it and made observations.
    
    Alberto Rango also looked for the object on that pass, from Rome, but was
    hampered by clouds, made worse by the moonlight. Pierre Neirinck, observing from
    northern France, shivered in the cold, and was hampered by dew forming on the
    lens of his binoculars.
    
    For tonight, using the above elements, I estimate prediction time uncertainty of
    about 1 min for Europe, and 1.5 - 2 min for North America.
    
    Ted Molczan
    
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