Optical 05 Dec 2007

From: Greg Roberts (grr@telkomsa.net)
Date: Thu Dec 06 2007 - 12:09:15 UTC

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    Observations 5 Dec 2007:
    ------------------------------
    
     Cosatrak 1 (Computerised satellite Tracking System).
    MINTRON low light level CCD surveillance camera (0.005 lux typical
    in non integration mode) and 0.00005 lux in STARLIGHT mode with 128
    frame integration.
    
     Used with 6 inch f/2.7 reflector,integrating for 96 frames
    which is equivalent to an exposure of 1.92 seconds per image.
    Faintest magnitude seen in "real time" was about mag +15
    
     Site 0433 : Longitude 18.51294 deg East, Latitude  33.94058 deg S,
    Elevation 10 metres - situated in Pinelands (Cape Town), South Africa
    
    
     For CLASSFD.TLE:
     ----------------------
    
     90013 03 564A   0433 G 20071205181728800 56 15 0225151+083507 39  +080 05
    90013 03 564A   0433 G 20071205182100700 56 15 0228434+084221 39  +080 05
    90025 04 800A   0433 G 20071205182125900 56 15 0228445+090755 39  +080 05
    90025 04 800A   0433 G 20071205182130500 56 15 0229536+085014 39  +080 05
    90025 04 800A   0433 G 20071205182134800 56 15 0230577+083253 39  +080 05
    90078 07 835A   0433 G 20071205184851800 56 15 0431025+045822 39  +140 05
    90078 07 835A   0433 G 20071205185027500 56 15 0432424+045911 39  +113 05
    90078 07 835A   0433 G 20071205185055600 56 15 0433120+045939 39  +115 05
    90078 07 835A   0433 G 20071205185326200 56 15 0435485+050005 39  +122 05
    90078 07 835A   0433 G 20071205185401000 56 15 0436244+050019 39  +115 05
    90078 07 835A   0433 G 20071205185741200 56 15 0440149+050123 39  +113 05
    90078 07 835A   0433 G 20071205185945200 56 15 0442233+050204 39  +115 05
    90078 07 835A   0433 G 20071205190455800 56 15 0447472+050334 39  +108 05
    90078 07 835A   0433 G 20071205190848700 56 15 0451502+050448 39  +108 05
    27169 02 001B   0433 G 20071205192546000 56 15 0048180+070146 39  +100 05
    27169 02 001B   0433 G 20071205192805200 56 15 0050393+070233 39  +100 05
    
    
     Strays seen:
    --------------
    Thuraya 2 geostationary
    27825 03 026A   0433 G 20071205182308800 56 15 0229284+084838 39  +110 05
    Atlas Centaur 2
    00694 63 047A   0433 G 20071205182737200 56 15 0405002+051415 39  +010 05
    Intelsat 704 geostationary
    23461 95 001A   0433 G 20071205184701300 56 15 0430402+051216 39  +110 05
    Delta 1 debri
    21435 75 052DT  0433 G 20071205185806000 56 15 0439478+050338 39  +080 05
    Scout X-4 Rocket body
    01358 65 032B   0433 G 20071205185927800 56 15 0443065+051257 39  +080 05
    Meteor 2-11
    15099 84 072A   0433 G 20071205190249900 56 15 0444588+050628 39  +050 05
    Intelsat 704 geostationary
    23461 95 001A   0433 G 20071205190557500 56 15 0449373+051239 39  +105 05
    Cosmos 1257
    12327 81 022H   0433 G 20071205193954400 56 15 2138416-053900 39  +075 05
    Breeze M Rocket body, range 27000 kms, steady
    31864 07 032C   0433 G 20071205202931700 56 15 0635490+105204 39  +107 05
    31864 07 032C   0433 G 20071205205233300 56 15 0659595+071956 39  +107 05
    
     Notes:
     -------
     (1) Purpose of observing session was to observe 90078.
    
           On saturday afternoon ( my time) 1st Dec I was doing routine radio 
    monitoring
           and trying to determine where the recently SKYNET satellite was 
    positioned .
           During this search I checked 2227.50 Mhz and found a relatively strong 
    signal
           doing some rather peculiar variations.  I monitored this for about four 
    hours and
           using a directional 18 turn helical antenna, was able to determine its 
    approximate
           azimuth and elevation and establish that it was slowly drifting 
    eastwards.
    
           Peter Wakelin was able to find the object on CCD exposures on two nights 
    and
           this enabled the orbit to be determined. The satellite is slowly drifting 
    eastwards
           at the rate of 13 degrees per day and will take about 27 days to do one 
    rev along
           the Clarke belt.
    
           Despite further monitoring of 2227.5 Mhz the strange behaving signal has 
    not
           recurred but has instead been replaced by a carrier with some small 
    amplitude
           frequency variations. This, combined with the optical behaviour, leads me 
    to
           think that the satellite is not operational ?   The behaviour on Dec 1 
    may have
           been a random event or was it commanded ?
    
           It would be worthwhile keeping a watch on this one. I will loose it 
    shortly as it
           dips below my eastern horizon but it will soon be in range of the 
    USA/Canada
           and, unless it performs a manoevre, the orbit is now well determined so 
    should
           be easy to find again. The transmission on 2227.50 Mhz appears to be
           continuous.
    
          This object ranges in variability from approximately mag 11 to fainter 
    than
          mag 15. I was unable to determine a well defined period other than it took
          between  213 and 240 seconds between bright brief flashes. The satellite 
    would
          brighten from invisible to mag 11 and sometimes do a short flash and then
          rapidly fade again. It also appeared to have periods when it stayed bright 
    for
          perhaps as much as 30-40 seconds. Sometimes bright periods occurred with a
          period less than two minutes.
    
     (2)Object reported as #90025 sighted as an UNKNOWN. Later found that
         90025 was predicted to pass this position at around this time,so based
         on this and the track angle observed Im pretty certain it was #90025.
    
    
     Cheers
    Greg
     
    
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    This archive was generated by hypermail 2b29 : Thu Dec 06 2007 - 12:13:30 UTC