Richard's mystery GEO satellite near Cone Nebula

From: Matson, Robert (ROBERT.D.MATSON@saic.com)
Date: Wed Mar 16 2005 - 17:49:32 EST

  • Next message: Richard Crisp: "Re: Richard's mystery GEO satellite near Cone Nebula"

    > Though Rob is an expert I tend to disagree.
    
    Bjorn is being kind here -- I'm definitely out of practice!  ;-)
    
    > My image shows the track of 76-4A inclined 3.9 degrees to the
    > declination grid (+10 runs just below the glint)  The scale
    > of UNID_314.gif overlaid on iridium_flare_xga_ov.gif is 1.96
    > degrees (118') over the 805 pixel vertical.
    
    I didn't bother to rotate images and do a slope comparison since
    I thought the match looked reasonably close in time, location and
    slope.  However, now that I've done so I see that Bjorn is right --
    the inclination is off by a couple degrees.  While this doesn't
    seem like a lot, it is enough to rule out 76-4A as a match.
    
    Symphonie 2 was on a parallel track, so it's not a good
    match for the same reasons.
    
    Ekran 8 and OPS 9442 were closer to the correct location in
    cross track (and on more nearly east-west trajectories), but
    their intrack positions are poor and the slopes are actually
    too far the other way (too horizontal).
    
    Nearby Kiku 2 (ETS 2) looks to be close to the correct slope, but
    shifted well to the east.  Bottom line is that none of these
    is a solid match.
    
    Two possibilities to consider:
    
    Are the observer coordinates correct and/or can they be provided
    to greater accuracy?
    
    Are the reported UTC date and time absolutely certain?
    
    Finally, answering Richard's questions:
    
    "So Bjorn, you say it is 76-4A?  And Rob, you say it is #8585 right?"
    
    No, #8585 is the same as 76-4A.  Bjorn didn't identify an alternate
    candidate (nor can I).  It remains an unknown unless the location, date
    or time were in error.
    
    > We are all pretty sure it is a LEO because of the EW travel, right?
    
    No -- I'm very confident that it is a *GEO* because of the EW travel.
    Could be a glint from a small piece of debris near GEO that isn't in
    the catalog.  By measuring the RA/Dec of two positions in the track
    and assuming a GEO orbit, I bet Ted Molczan could generate you a
    search orbit.  But you'd need to reacquire it soon in order not to
    lose it.  If successful, it might very well be the dimmest object
    ever discovered by an amateur!  --Rob
    
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