Re: Dec 6 Telstar 401 observations

Date: Tue Dec 06 2005 - 10:56:05 EST

  • Next message: Kevin Fetter: "interesting - where symphonie 2 flashes"

    Thanks for your observations!
    I have now entered most/all  of them into my mid-november model, with 
    axis at RA 16:15, declination +79.7.
    It seemed accurate at the time, but had a surprisingly low 
    0.02 h/y, vs. 1-6 h/y for other flashers I have analyzed.
    The cone angle was about 86 degrees, which was noted also in nov.
    though other observations clustered around 89 degrees, both of which 
    very normal for comsats.
    A polar chart showing position of my axis, and of reflecting surfaces 
    at the time of each "first" and "last" bright flash I have noted 
    2001-2005, is available at
    (Because of the lack of a proper polar chart in Excel, I had to 
    and show a X-Y scatter chart, so declinations are 90-abs(value shown))
    Starting backwards with some December obs, it looked like a 
    discontinuity in cone angle, jumping back to 89 degrees.
    Signs of this is also seen in the polar chart above. A similar but 
    smaller effect is seen comparing nov.2003 to dec.2003.
    Looking at the angles in columns U+V (thought to be different 
    there is a jump of 1.5 degrees nov.27-29, but looking at the angle 
    values there is a regular drift before (85-87) and after (89-90). 
    This can be seen in a rectangular plot:
    Some pairs of observations (one observer, one day) is indicated by 
    This cone segment is neither long, nor accurate, enough to calculate 
    radius. If I assume around 90 degrees angle, I will find a new pole, 
    will have to find a larger precession rate, to avoid disrupting the 
    near-circle I found. However, there ARE slight indications in the 
    segments that the axis is/was not where I've put it.
    The data for nov-dec and some calculations are shown in
    PS1. I will start using a new mail address soon, to try to avoid the 
    amount of spam, without changing ISP. Please be observant.
    PS2. Question for Rob and other analysts: Is it likely that spin axis 
    precession is around an axis normal to the orbital plane, instead of 
    equator plane I have assumed so far?
    COSPAR 5918 +018.1045E ,+59.2985N,22m 
    COSPAR 5919 +018.6172E ,+59.2576N,33m
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