Re:Magnitude #22519

From: Greg Roberts (
Date: Fri Jan 22 2010 - 13:27:38 UTC

  • Next message: "Re:Magnitude #22519"

    Hi Jim
    22519 (USA 89R) is a funny one.
    It goes through quite a range of magnitudes and has a slow variability 
    cycle, so can be very faint for a long time.
    When I tracked it a few days ago I initially did not see it crossing the 
    field of view of the video monitor. A few minutes prior to this I had tried 
    it on an earlier position and observed a satellite on the monitor at about 
    magnitude +8 but ignored it because it was about 90 seconds off the 
    predicted time, so I assumed it was an "unknown" as I had nothing predicted 
    at the time observed.
    I then proceeded to do a search for #22519, first setting a few minutes 
    ahead of the predicted track-in case it came early, and then waiting past 
    the predicted time for a few minutes in case it was late and saw nothing on 
    the monitor.
    I then moved my mount to the culmination position and then swept back and 
    forth in azimuth keeping the elevation constant and every 2 degrees or so 
    stopped sweeping and put the mount into auto track mode and tracked for a 
    few seconds. This effectively integrates the image so a faint satellite 
    appears stellar (and a few magnitudes brighter) and the stars trail. This 
    was done using the CCD camera.
    I did this several times and finally located #22519 and then automatically 
    tracked on it for a few minutes . Initially I could see nothing on the video 
    monitor but by the time I finished my few minutes track on 22519 it was 
    quite easy on the monitor.
    So, if you dont see it at the first position try another position a few 
    minutes later -- do this often enough, and, provided the satellites is not 
    running too far off, you should eventually see it.
    Incidentally I was tracking it at a range of about 8000 kms if memory 
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