Acceleration Report : 22 Aug 96: 92- 30 J = 21984

Kurt Jonckheere (kjonckheere@unicall.be)
Fri, 23 Aug 1996 00:12:09 +0200

I just came home from observing 92- 30 J = 21984.  I saw it flashing
at 20h53m UT (Aug 22) with a period of 8.19 seconds.  It was 
flashing rather regularly although there were some flashes that
were brighter and sharper than the others.

These are the observations of the last months:
92- 30 J 96-03-11 20:07      MR   85.7 1.0   8 10.7
92- 30 J 96-03-12 19:42      KJ  215.0 0.3  20 10.75
92- 30 J 96-03-13 19:14      LB  107.4 0.1  10 10.74  FF, mag 4->inv
92- 30 J 96-03-14 20:51      WV  129.8 0.3  12 10.82
92- 30 J 96-06-05 22:19:34   LB   79.4 0.2   6 13.23  FF, mag 5->inv
92- 30 J 96-06-06 23:54:16   LB  132.3 0.2  10 13.23  FF, mag 4->inv
92- 30 J 96-06-07 23:26:39   LB  159.4 0.2  12 13.28  FF, mag 4->inv
92- 30 J 96-06-09 22:34      TC  133.4 0.2  10 13.34  FF, mag +4.5
92- 30 J 96-06-12 23:15:37   LB   66.6 0.2   6 11.10  FF, mag 6->inv
92- 30 J 96-06-13 22:47:55   LB   65.6 0.2  10  6.56  FF, mag 5->inv
92- 30 J 96-06-15 00:29:03   LB   81.2 0.2   6 13.53  AA, mag 3->inv
92- 30 J 96-06-15 21:59:47   LB   54.2 0.2   4 13.5   FF, mag 4->inv
92- 30 J 96-06-15 22:00      KD  149.8 1.0  11 13.6
92- 30 J 96-06-15 22:00      KJ  217.4 0.5  16 13.59
92- 30 J 96-06-15 22:00      TC  108.2 0.2   8 13.52  FF, mag +4
92- 30 J 96-08-21 03:39      PM   56.3       7  8.0
92- 30 J 96-08-22 20:56      KJ  278.5 0.5  34  8.19  

The characteristic time is defined as the time in days needed to multiply
the period with a factor 'e' (e = 2.71...).  
The characteristic time of this rocket is about 450 days, indicating that
if the period should have evolved normally, the period should now be
about 15.9 s.  
Paul Maley also noticed (in a private mail) that "he had the impression 
that the maxima were not uniform".  
This might be an indication that the *real* period is double, being
about 16s which is remarkable near the 15.9 mentioned above.

I also wasn't able to find out if we are watching secundary maxima.
I saw rather regular variations, each 8.2 seconds.

The entries in our database only mention secundary maxima a very
few times, so there probably was indeed an acceleration of the rocket
which coincides with a sudden change in Mean Motion around Aug 14.
If our observations are correct, the period is (already) going up
again, one week after the acceleration.  

Normally it takes more than one week before the period of an accelerated
rocket is increasing again, so there are still doubts...

To be sure if there was an acceleration we need more observations !

Who's next ?

latest elements :
21984
1 21984U 92030J   96234.11968175 -.00000004 +00000-0 +10000-3 0 06484
2 21984 073.9991 127.0764 0123821 232.1459 126.8324 12.22109990188158
------------
!
Don't forget to send your observations of flashing satellites before
Sunday evening to be included in the next PPAS-update. (see below).
!
-----------

Happy observing,

Kurt Jonckheere


-------------------------------------------------------------------------
        Kurt Jonckheere (kjonckheere@unicall.be)   51.2 N  2.9 E 
    observations collector for the Belgian Working Group Satellites: 
Send your observations of flashing satellites, preferrably in the correct
     PPAS format to obs@physics.oxford.ac.uk or obs@physics.ox.ac.uk
              Where is my mind ?      --       The Pixies
-------------------------------------------------------------------------