Re: Eccentric flashing UNID (Telstar 402)

From: Mike McCants (
Date: Mon May 22 2000 - 09:31:47 PDT

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    Ed Cannon wrote:
    >I did not come up with any good candidates using loose parameters 
    >with Findsat and alldat.tle as the source of orbital element data.
    As we were driving home, Ed suggested that the unid might be Telstar 402.
    I agreed that this was a possibility.  It had been showing up in my
    predictions every once in a while recently.  I had deleted its
    prediction before printing predictions for Sunday evening.  But I
    remembered that my last recorded obs had a period on 0.8 seconds and
    that there was a good chance that this agreed with the observed
    fundamental period of 3/4 second.
    So when I got home I ran a prediction for Telstar 402 and it was
    a good match.  My son was using our Internet connection to download
    music.  He asked me if I wanted him to hang up, but I was so sure
    that Ed would also match the obs with Telstar 402, that I told him
    not to hang up.  So I didn't call Ed and he couldn't call me.
    > 5/22 at 3:17UT - alt 50.5, az 157  (seen in binoc field near 19649, 88-102A)
    Telstar 402 gives a 27 seconds time residual and a 0.2 degree
    cross-track residual from this alt/azi position.
    Telstar 402
    1 23249U 94058A   00142.27935861  .00125575  44451-6  16772-2 0  2711
    2 23249   7.1801  61.5875 6287198   2.8542 359.4815  3.70830952 60607
    >Mike found that by wiggling the telescope a little, the two sub-flashes 
    >of the double flashes could be seen separately (split?) in the 
    >field of view.
    I thought this was a very interesting phenomenon.  If one could
    estimate an angular speed for the telescope motion, then the apparent
    distance that the flash was visible could be translated into a
    duration time and the dark space between the two flashes could
    be translated into a separation time.
    Suppose the telescope was being moved about 1/2 degree per second.
    Then a perceived distance for the flash of about 1/20 degree would
    mean a flash duration of 1/10 second and the distance between the
    flashes of about 3/20 degree would mean a flash separation of
    3/10 second.  It is possible that the speed could have been 1 degree
    per second and the corresponding times would be 1/20 second duration
    and 3/20 second separation.
    Mike McCants
    Austin, TX
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