Iridium 14 flash timings

From: Ed Cannon (ecannon@mail.utexas.edu)
Date: Fri Mar 24 2000 - 02:39:08 PST

  • Next message: Rainer Kracht: "DSP 15 obs"

    My recent observations (using one-power) of Iridium 14 
    (97-30A, 24836) have puzzled me.  It seems to be doing 
    a phase shift, or maybe two (or even three?) of them.  
    I'm somewhat uncertain as to the object's rotation 
    period, although I think it's about 6.5 seconds.
    
    Here's the series of times from March 10, observed from 
    Austin (30.31N, 97.73W, 150m):
    
    6.49 6.50 
    7.41  
    1.82 4.67 
    1.79 4.71 
    1.79
    6.50 6.57 
    7.54  
    6.69 6.24
    
    The split cycles (1-4 or 4-1) always begin and end with 
    the short 1.75-second partial cycle.  Also, as they begin 
    one is brighter, then they are nearly equal in magnitude, 
    and finally the other is brighter.  The brightest flashes 
    are in negative magnitudes, possibly -3 or -4 (?).
    
    Here are the times from last night (2000-03-24 UTC) from 
    Austin -- a nice pass in spite of it racing to stay ahead 
    of a fairly large cloud:
    
    0.00 (= 1:31:07.99)
    6.38 6.43 6.45 6.50 6.45 6.48 6.47 6.53 
    7.38
    1.98 4.44 
    **** 6.51 
    **** 6.44 
    1.86 4.67 
    1.78 4.64 
    1.86 4.66 
    1.78 4.75 
    1.76 4.66 
    1.75 4.80 
    1.70 4.75 
    1.75 4.75 
    1.69 
    6.49 6.52 6.53 6.43 (= 1:33:45.57)
    
    (The two instances of "****" mark when I should have clicked 
    on a secondary flash that I did in fact see.)
    
    I have similar sets of times for March 13 and 20.  
    
    I'll add my vote to Don Gardner's on Cosmos 2367 (26040, 
    99-72A).  It was about the same magnitude as Castor and 
    Pollux on its very good pass over here last night.  Luck 
    was favorable again in spite of a lot of clouds.  (The only 
    other one I saw last night was HST.)
    
    Ed Cannon - ecannon@mail.utexas.edu - Austin, Texas, USA
    
    -----------------------------------------------------------------
    Unsubscribe from SeeSat-L by sending a message with 'unsubscribe'
    in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org
    http://www2.satellite.eu.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Fri Mar 24 2000 - 02:42:44 PST